February 09

Sponsored By Dresser-Rand

Kevin Klucher, Rishitha Dias, Reme Meck, John Hayles, Ammar JangwarbalaDresser-Rand sponsored a senior design team in the academic year 2007-08 in the creation of a self-contained pump flow loop to perform flow visualization. The purpose of this year’s project is to further improve the existing pump loop as well as increase the system capabilities for more complicated flow characteristics and increase the number of possible pump element configurations. This document will serve the purpose of updating the valued design review consultants regarding the existing platform, issues the group has found, and several proposed solutions for each subsystem.

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Table of Contents

State of Previous Project’s Pump Flow Loop.................................................................3

Current Project Progress..............................................................................................4

System Architecture.....................................................................................................5

Impeller and Diffuser Design Selection and Analysis.....................................................5

Volute Redesign and Optimization...............................................................................7

Housing Expansion and Raising....................................................................................8Constraints on Enlarging the Pump.................................................................................................................10Why Raise the Pump?.............................................................................................................................................11

Tank Reposition..........................................................................................................12

Riser Analysis.............................................................................................................13

Draining.....................................................................................................................13

Sealing.......................................................................................................................13

Fastening....................................................................................................................14

Safety.........................................................................................................................14

Graphical User Interface.............................................................................................15

Test Plan....................................................................................................................17

Risk Assessment and Specification Analysis................................................................18Risk Assessment & Risk Mitigation Plan Summary..................................................................................18

Final Engineering Specifications for Design Considerations.........................................20Meeting Specifications...........................................................................................................................................20

Conclusion..................................................................................................................20

Appendix A: Impeller and Diffuser Design Equations…………………………………..………………………..22

Appendix B: System Fluid Mechanics Analysis............................................................24

Appendix C: Full Risk Assessment...............................................................................26

Appendix D: Vibrations Analysis.................................................................................28

Appendix E: Riser Drawings........................................................................................29

Appendix F: Impeller and Diffuser Drawings...............................................................30

Appendix G: Fastening Analysis..................................................................................36

Appendix H: Entire System Assembly.........................................................................38

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State of Previous Project’s Pump Flow LoopThe previous project is composed of two carts, one with all of the computer components and data acquisition interfacing, and the other with the pump flow loop mounted in a highly visible position. The fluid reservoir is quite large, and to achieve visual access to the centrifugal pump, it had to be mounted on the bottom shelf of the cart. Piping led from the reservoir to the inlet, with only a primer pump intake between those two points. However, after the flow outlet, there is an extensive system of piping that serves as a mounting point for several sensors for all relevant data acquisition. All of the measurements and inputs should be accessed through a LabVIEW interface shown later, but the remote motor control function does not work, and the speed of rotation must be changed manually with a standalone motor control box. The main components of the current pump test loop that this project will focus on are shown in the following computer model screenshot.

This system is designed primarily for one type of impeller to be mounted and then remain affixed within the system for extended periods of time. To serve its proposed function in the classrooms and laboratory exercises, it must be interchangeable within a reasonable period of time without excessive effort. The five mounting screws for the clear pump housing are set in locations where there is very low tool clearance, thus it is very difficult to remove in a short time. The sealing mechanism, rubber hosing, is glued inside a channel extending around the fluid interface area on the back housing, and does not provide uniform sealing properties due to a decline in the material quality and sealant. As mentioned before, the system was designed for use with only one impeller, and the sealant does not sustain itself throughout the attempts our group made to remove and remount the impeller. This creates a problem with the flow dynamics within the impeller cavity.

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Flow within the current pump cavity with the straight-edge impeller designed by the previous team is shown below.

Current Project ProgressThe team has addressed every concern and cross-referenced design solutions to customer needs and engineering specifications. All project risks have been accounted for and mitigation plans have been set. Areas of improvement proposed and designed for include new impellers, the addition of a diffuser ring, an optimized volute in an expanded housing, with improved sealing and draining methodology, along with an GUI that enables more variable control. To allow for the expansion of the housing, the motor, drive shaft, and bearings will have to be raised on aluminum risers that have been optimized for vibration damping. All changes took into account safety concerns and dimension constraints of the PIV (Particle Imaging Velocimetry) system, as well as tool clearance. The fastening methods used for all parts have been slightly modified; faster interchange time will be achieved using a handheld power screwdriver with a fixed amount of torque to prevent damage to the components. All of these proposed designs have been subjected to rigorous engineering analysis and computer simulation using various software programs, and have been proved to meet the engineering specifications. Initially, many solutions were considered, but through logical assessment of the benefits versus the adverse impacts of all options, the designs were narrowed down to those that this document will elaborate upon.

The following pages are the analysis documentation of all design choices, including all relevant engineering analysis along with computer models and simulations if applicable. The engineering specifications and system architecture are presented up front so that they can be referenced for all design analysis.

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System Architecture

Impeller and Diffuser Design Selection and Analysis

The previous project team converted rotational mechanical energy to pressure and head. They used 8 flat blades rotating to create fluid separation. The fluid separation created a pressure and suction side for each blade. This is the most basic example of a centrifugal pump.

The P09454 Project Team studied typical centrifugal pump design to progressively modify

a series of impellers designed to achieve better efficiency in converting rotational energy to fluid flow and pressure. All equations used and calculations done for this portion of the project are included in Appendix A.

The first item to engineer was the angle of the blade versus the radial axis. The greater the blade angle from the radial component the more fluid velocity the

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pump will transfer to the pumped liquid. The preferred angle to balance the pump head and flow is 70°.

The original impeller used eight blades. The typical number of blades used for pumping a liquid fluid is six. The slip for a six-blade system is calculated as 0.96 while the slip for an eight-blade system is 0.825. To demonstrate the effect of fluid slip the team will create both a six and eight version of each blade configuration.

The second variable to consider is the diameter of the inlet. For given flow and rotational speed the impeller has an optimum inlet diameter. The inlet diameter for the P09454 pump is calculated to be 1.1907 in. All impellers designed for in the P09454 project group will be designed for this inlet diameter.

The next variable to account for is the fluid inlet angle. The inlet angle is determined to be 54.75°. With the inlet angle set at 55° and the tip angle at 70° the blade must create a continuous path to follow from inlet to exit. This design for a vertical blade with different inlet and tip angles is a typical centrifugal pump design called a radial cascade.

The blade angle is not enough to control the flow in the pump housing alone. The meridional angle must also be applied. The typical exit angle for a mixed flow pump 22°, this design calls for an exit angle of 25°.

The inlet angle can also be calculated to be 55°.

The diffuser angle can be accounted for by two methods. Using the calculated flow for

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a given blade design angle the lead angle can be determined. This method found an inlet angle of 86.8° or near enough to be left at 90°.

The diffuser angle can also be determined from the pump coefficients. The pump coefficients determine that the diffuser angle as 77.2°.

Volute Redesign and OptimizationThe volute, based on the impeller and diffuser diameters and flow properties, was optimized for the best balance between head and flow. The tangential velocity of the fluid exiting the diffuser was obtained from the diffuser technical analysis and applied to the equation for volute optimization. This will result in a more efficient conversion between pure velocity coming out of the diffuser and the head produced by the system. For the best balance between those two variables, the volute must have a constant cross sectional area in proportion to the fluid entering the cut water zone. A sample of the degree-by-degree radius calculation is shown below, along with the resulting volute shape:

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Housing Expansion and RaisingWhen considering the addition of a vaned diffuser ring, which is a core project goal, the current pump housing and impeller size do not allow space for one.

Because of this, either the housing has to be enlarged or the impeller shrunk to accommodate a diffuser.

The benefits of shrinking the impeller are as follows:

Uses the same clear acrylic front pump cover, no redesign necessary

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The costs associated with shrinking the impeller:

The aluminum pump back housing will need to be completely redesigned Optimal impeller inlet diameter will have to be remachined on current front housing

By instead enlarging the pump housing, these benefit s are seen:

Ample space for impeller, sufficiently large diffuser, and redesigned volute collector. New scaled-up front housing with optimal impeller inlet diameter, instead of arbitrary

value. Impeller mounting and shaft seal can be re-used. Aluminum back housing scaled up instead of completely redesigned. Pump flow paths are geometrically bigger, allowing for better naked-eye observation

and improved PIV and high speed camera flow mapping.

Potential issues with enlarging the housing are:

Motor will need to be elevated to accommodate higher pump centerline. Aluminum back housing and acrylic front housing will need to be scaled up. New gaskets will be needed for a longer pump sealing perimeter, larger clamping force

may be needed.

Addressing the issues of enlarging the housing, the following conclusions can be drawn.

The motor will be elevated anyways to accommodate a 2 inch rise in pump centerline to improve flow visualization, allow for a better seal around the pump housing, allow for more drainage options, and permit needed tool clearance for impeller-diffuser change outs. Because of this, additional elevation due to an enlarged housing becomes a minor issue.

The current system leaks, partially due to a poor sealing system and partially the lack of clearance around the seal to ensure alignment. Raising the pump housing will alleviate some of the problems, and a redesigned gasket seal with five ¼-20 hex head bolts provides sufficient clamping force for the larger housing. Since new gaskets are being ordered anyways for the redesigned seal, and the clamping force has been shown to be sufficient, a longer sealing perimeter is no longer a problem.

The only real issue associated with enlarging the housing is that the pump front and back housings will need to be scaled up to accommodate a diffuser ring. This is hardly different from needing to redesign the back housing and remachining a larger impeller inlet on the front housing. Considering the ample benefits that can be seen with a larger housing, as compared with only shrinking the impeller, the decision was made to enlarge the housing.

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Constraints on Enlarging the PumpWhen doing initial considerations for the new pump housing size, it was the general consensus that going from a 7” by 7” pump housing to a 10” by 10” housing was the “best choice”. This was determined by largely arbitrary selection criteria. While it did give an initial idea for direction, it turned out to be the optimal choice for many reasons.

P09454 Pump Housing Resize A B C D  8x8 pump

cover9x9 pump

cover10x10 pump

cover7x7 pump cover (ref) 

Selection CriteriaSpace for Volute & Diffuser - 0 + -LOS for High-speed Camera + 0 0 +Material Required (Al & acrylic) 0 - - +Eye clearance for PIV + 0 0 +LOS for PIV 0 + + -Matches Base Size - 0 + -         Sum + 's 2 1 3 3Sum 0's 2 4 2 1Sum -'s 2 1 1 3Net Score 0 0 2 0Rank 2 2 1 2

Continue? No No Yes NoTable 1: Housing Resizing Screening Matrix

In turbo machinery, there is no industry standard for impeller-diffuser-volute spacing. The rule of thumb states that a clearance of 5-10% of the outer diameter of the impeller is sufficient space between it and the diffuser.

The size and shape of the diffuser is largely based on optimal flow conditions. For the most efficient impeller design, a flow-rate of about 23 gallons per minute with a tangential exit velocity of 93.73 inches per second are obtained. With a blade height of 0.8 inches (the chosen housing depth), and an impeller clearance of 7.5% (0.3 inches) the outer diameter of the diffuser needs to be 6.25 inches.

Between the diffuser and the volute tongue, an additional clearance of 5% of the diffuser’s O.D. is added to prevent pump lock-up in sup-optimal flow conditions. This brings the beginning of the volute circle to a 6.56 inch diameter. The end of the volute curve lies on a circle of about 8.3 inches in diameter.

With a 10 inch square pump housing, a minimum of 0.85 inches on either side is left for sealing.

More options are available for larger impellers and different fluid collection methods for future flow visualization projects.

The pump housing is now the same width as the base plate it rests on, making pump alignment easier.

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By making it smaller, between 7” and 10”, the benefits to the seal shrink, and fewer options can be explored for impellers. Additionally, it becomes harder to align the pump. A smaller housing would not accommodate a sufficiently large diffuser for the impeller diameter chosen. For all of these reasons, the decision was made to go forward with resizing the pump housing to a 10” by 10” square.

Why Raise the Pump?Improving the change out time of the impeller and diffuser is a core need and design specification of the project. Currently, hex socket bolts are used to seal the housing. These are removed and attached by using an Alan wrench. Because there is no clearance between the bottom of the housing and the base plate it rests on, the 2 bolts on the bottom edge of the pump housing have no room for attachment and removal. There is a maximum 180o range of motion with one bolt, and about 100o on the other bolt.

In addition to tool clearance, the housing does not seal correctly. Since there is no room around the bottom edge of the pump housing to ensure a proper fit, leaks can form there.

When the pump system is stopped, water either runs out of the discharge or inlet pipes, except for the fluid still inside the pump housing. This is the system “low point”, and the only way out for the water is through the bottom of the housing. Since quick and convenient change outs of impellers and diffusers in a laboratory setting are a project need, more options for system drainage are needed.

The solution to all three of these problems lies in raising the elevation of the pump housing, bearings, and motor above the level of the base plate. The only question is: How far should the pump be raised?

There are some constraints to the pump housing height.

The “maximum” is determined by a minimum eye clearance for safety when using the PIV laser with the pump.

o Because of this eye clearance standard, the top of the pump housing can be no higher than 48 inches above the floor.

It needs to be ensured that there is sufficient tool clearance for the ¼ - 20 hex bolts by ASME standards, which has been verified as 0.45 inches.

The cart on which the pump system rests has a 2 inch lip around the edge that impedes line of sight of the lower half of the pump housing.

The current system’s inlet pipe needs to be repositioned to accommodate new pump housing elevation. Discharge is through a flexible tube so it is unaffected.

A basic screen of a few different options on repositioning was explored.

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P09454 Pump and Motor Reposition ConceptsA B C D

(Reference)Selection Criteria 3 inches 2 inches 1 inch 0 inchesTool clearance + + - -Material Needed - - 0 +LOS for PIV + + 0 -Drainage + + 0 -Eye clearance (Safety) - + + +LOS for high-speed camera - 0 0 +Sum + 's 3 4 1 3Sum 0's 0 2 5 0Sum -'s 3 1 1 3Net Score 0 3 0 0Rank 3 1 3 3

Continue? No Yes No No

Table 1: Pump Reposition Screening Matrix

Though the 2 inch option looked most attractive, it needed to be proven.

With a 2 inch rise, and adding in a 10 inch square pump housing, the new system maximum height is 46.75 inches, within the laser eye clearance. This height is the minimum required to place the entire pump housing above the steel lip currently obstructing line of sight of the flow. Additionally, the inlet pipe can be repositioned to feed into the elevated housing with virtually no system redesign, something that the 3 inch reposition cannot offer.

All in all, a repositioning of 2 inches offers the most relevant benefits to the projects specifications, while not conflicting with any customer needs.

Tank RepositionTo reduce system head losses, the team considered reducing the piping and raising the fluid reservoir to the top level of the cart. This would eliminate the need for priming, but bring a draining issue to the surface since the system would not naturally drain without a mechanism to force the water out. Based on the system fluid mechanics analysis, the head would be affected adversely by raising the tank, and this would not benefit any specifications in a manner so greatly that it overcomes the work involved. Therefore, this is judged to be outside the team’s project scope and will not be considered. The fluid mechanics analysis can be found in Appendix B. The proposed system would have less plumbing connections that contribute to head loss but would increase the amount of work for the team, while the current platform performance properties are known and proven. Altogether, the tank reposition is found to be negligible for any project benefits and will not be done.

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Riser AnalysisThe motor and bearings for the drive shaft must move up to match the newly expanded and lifted housing for the turbomachinery assembly. To do this, risers that accommodate the existing design for the fastening of the bearings and motors have been designed. However, the riser for the motor will not be aluminum alone, it will consist of half an inch of vibration damping rubber glued to the base plate with permanent epoxy, with the remainder of the height being filled by an aluminum block that will be machined for precise fastening positions. A full engineering analysis of the worst case vibration transmittance between the motor to the cart was done, and it was found that a maximum of 0.0003614 inches would be transferred to the cart, well within the acceptable range of vibrations to ensure the high speed camera and PIV system will not be influenced. This will also provide a means of preparing documentation for possible future flow visualizations with more complicated vibrating turbomachinery. The riser for the bearings will also serve as a shelf for the back aluminum housing of the pump, while providing clearance for the drainage tray. The vibrations analysis is in Appendix D, while the drawings of the riser are in Appendix E.

DrainingTo reduce the complexity of this and allow the team to focus on more relevant objectives that will contribute more to the final engineering specifications, the draining system was simplified to a tray that will be inserted below the housing to collect any water that is left in the pump cavity after the system is drained. This tray has been calculated to have enough volume to hold twice as much water as needed, so that there is no chance for spillover. The user will then be able to return the water to the reservoir at their own leisure, while not having to clean up the cart of any spilled water as they would need to do with the current system.

SealingAfter considering multiple alternatives, it was deemed that the industry standard of silicon o-rings would be satisfactory to prevent leakage from the pump housing. Due to wide availability of o-rings, this would be an ideal solution for the sealing. The back aluminum housing will have a groove that will be snug against the o-ring tubing to prevent any imbalance in sealing forces. A fixed o-ring would be an improvement from the cord that was cut for the previous housing since it would not have any gaps in the sealing, and it also would be more durable than the rubber material used previously. The fluid being used in the system is water, which has no issues in the interface with silicon. No epoxy will be used for the sealing because of the need for quick interchangeability; the previous team had epoxy on top of the cordage since the system was only designed for use with one permanent impeller. This would lead to rapid degradation of the seal with multiple uses. This manner of sealing would not have any issues with line of sight from either the side or the front, therefore satisfies the customer need of flow visualization with no obstructions. Splitting the distance between the outside of the block and the outer diameter of the

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pump cavity, while accounting for proximity of the seal to the actual fluid system, gives a diameter for the o-ring groove of 8.16 inches. Relating the two diameters and accounting for the cross section ratio of the groove and o-ring, the optimal o-ring would have a diameter of 0.094 inches, while being mounted in a groove of a depth of 0.062 inches. This ensures effective sealing of the system based on the compression from the fastening analysis.

FasteningThere were many trade-offs made in this design category since most options in the selection process interfered with the line of sight in some way, which is a critical component of this project’s success. It was decided that a similar setup as the previous team’s would be used, but with a few changes. Mechanical design of the fastening system based on the constraints of the impeller mounting plate was done and it was found there would be approximately 380 pounds of force holding the impeller to the mounting plate. The diffuser will utilize three flat-head bolts to lessen the influence on the flow, and they will have a total clamping force of around 1560 pounds. The housing will use longer bolts, reducing the force from each bolt, but makes up for this with five bolts. Due to the increase in system height, there will be abundant tool clearance for a handheld power screwdriver with a standard Allen key to be used for all bolts in the interchangeable components. The bearings and the motor both will use the same attachment as before since they are not to be removable except for maintenance. There will be around 529 pounds of force holding each of the bearings and the motor to their respective aluminum plates. All of these clamping numbers are more than sufficient to hold their components in place during standard operating conditions. The spreadsheets showing each fastening force analysis are shown in Appendix H.

SafetyLaser Safety Considerations:

The PIV system will be used in the laser lab due to the immobility of the laser. Therefore, the access to the laser & PIV studies will be limited to a few individuals at any given time. Therefore, the pump system with PIV studies in an undergraduate lab section is infeasible.

Furthermore, the laser lab already has safety measures in place that would be more than adequate to meet the demands of the project. Safety eyewear and clothing are already part of these measures employed in the lab when the laser is in operation.

However, as a precaution, the team has set a specification for the maximum pump height for the system to allow at the line of the laser to be at least 12” below the eye level for 95% of the population.

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Maximum Pump Housing Height Calculations:

Criteria:

The maximum pump housing must be at least 12 inches below the eye height on 95% of the population as a safety precaution against damage from the level 4 intensity laser equipment used for the PIV studies.

Assumptions:

Designing to fit the 10th percentile female will ensure that 95% of the population fit the requirements of the system

The eye height of an individual is 0.936H where H is the individuals height Source: ANSUR database, for females, sample size of 2207

Summary:

The mean height for females is 64.15 inches, while the 10th percentile is 61.06 inches; therefore the eye height for the 10th percentile of females is 57.15 inches. Because of this, to be low enough to be safe for 95% of the population, the upper limit of the pump housing must be approximately 12 inches lower than the eye height. The maximum pump housing height at the top of the block is calculated to be 45.12 inches.

New Design Constraints:

ParameterHeight (in)

Existing Housing

New Housing

Center Line 38.25 Variable

Top Edge 41.75 45.15

Table Height 34.75 34.75

Table 1: New Design Constraints & Existing Design Parameters

Graphical User InterfaceThe Graphical User Interface inherited from the previous group has been analyzed, and it was determined that the only portion of the LabVIEW VI file that did not function was the motor control module. This is one of the engineering specifications that needs to be met, therefore this will have to be troubleshot. The wiring for the communication between the motor control box and the PC needs to be acquired since the previous group’s wire was roughly spliced and easily shorted out or disconnected when it came into contact with the cart. Another way the team will improve the GUI is to add the data from an ammeter attached to the motor, which

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will measure the power input and compare that value to the flow measurements to get an output for the efficiency of the pump instantaneously. Other than these two improvements, there are no additions needed to meet customer needs and specifications. The current output window in LabVIEW is represented with the following screenshot:

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Bill of Materials

Test PlanThere will be several basic tests performed on the material being used for the impellers and diffusers. A simple drop test from the height of the cart will be performed to check if the material can withstand the impact force without adverse effects. A vibration test will be conducted to check for the transmittance of motor vibration to the cart to ensure that the rubber damping block will do its job. Specific torques will be tested for the fastening to determine the proper limit for tightening the bolts without damaging the components. Checks to see if the sealing system functions as designed will also be done. The draining system will be verified to ensure it handles the proper amount of fluid volume without overflow. Flow visualization will be performed when the system is assembled, with both the high speed camera and the PIV system, to see how the flow compares to predicted results.

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Risk Assessment and Specification Analysis

Risk Assessment & Risk Mitigation Plan SummaryVery High Risk Items:

R1.04 – The sealing system is critical to the success of the project and thereby must work well for the project to be a success. The sealing design is sound and the analysis suggests that the seal will perform as intended and thereby have a very low likelihood of failure. Furthermore, the seal can be reinforced using a tube of sealant if the need arises and thereby making the risk mitigation action simple and effective. In consideration of the risk and mitigation action this item can was classified as a low risk component for the future.

R1.14 – The risers will support the pump housing and the motors. The risers were considered a high risk component because of their exposure to vibrations from the motor. The team further analyzed the design and performed a vibrations analysis of the new designs. The engineering analysis suggests that the new riser design is acceptable and will reduce the risk of failure. The team believes the new design has a moderate level of risk and will mitigate that by introducing a budget and schedule buffer in the master plan.

R2.09 – The Impeller back plate is a critical component of the housing design as the impeller is fastened onto it. Furthermore, the back plate is connected to the motor and is a dynamic component in the system. The assembly and disassembly of the back plate will be minimized during the testing phases of the pump. Furthermore, the design and the components of the back plate assembly will be studied and researched by the team to effectively and immediately react to an unlikely failure of this sub assembly. Therefore, the updated risk level is low risk.

R3.03 – Volute disassembly will increase the amount of components that the user must deal with. Therefore, the team has decided to eliminate the interchangeable volute design and stick with the current design of using one component for the volute & front housing. Therefore this risk is not irrelevant through design changes and is a negligible level of risk.

R3.06 – The design of the system might require a certain level of exertion and dexterity to align and flush the front and back housing. The team has considered this and updated the designs to have tool and hand clearances that can be used to maneuver the housing into place. The team is confident that the design changes will help the assembly process and thereby reclassify as a moderate level risk. Additionally, the team would leave a buffer in schedule for testing & troubleshooting with respect to sealing.

R4.05, R4.06 – Outsourcing of designs can adversely affect the schedule of the project. The team will design majority of the components to be created in-house at RIT. For the parts that will require outsourcing, the team will submit the designs ahead of time and plan buffer times into the master schedule of the project. Furthermore, the team will

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use rapid prototyped parts for testing while the outsourced components are being fabricated.

High Risk Items:

R1.01, 1.02, 1.03 – The engineering analysis shows that the impeller, diffuser and volute combinations will not likely reach the engineering specifications already set. The team does not see a feasible mitigation action in order to reduce the gap between the designs and the specified performance levels. The team will accept the risk as High Risk and initiate conversations with the customer in order to revise the specifications.

R2.01, R2.02 – The impeller/diffuser failure is categorized as a high risk factor due to the fact that these components are the main focus of the project. Even though the likelihood of failure is low the severity of such a failure is high. However, the engineering analysis and design meet the specified factors of safety and thereby are not likely to fail. Furthermore, the materials for the impellers and diffusers will have a significant amount of surplus inventory that can be used to remake critical components in case of a failure. The testing phase will be moved earlier in the quarter to allow time for the fabrication of parts if required. Therefore, the items are reclassified as Low Risk items.

R2.11 – PC failure will cause the team to invest much time and resources to recreating the GUI. The team has already completed backing up the existing GUI and thus diffusing the threat level and reclassifying as Negligible Risk. Furthermore, the team will set a reserve in the budget to accommodate for any unforeseen equipment failures such as motor, motor control, PC components and instrumentation components.

R3.10 – The amount of fasteners used on the components could cause the disassembly time to increase. The team has already made design efforts to standardize the types of fasteners used on all the components. Furthermore, the designs have considered the tool clearances in the design that will reduce the time required for assembly and disassembly. If the time is still too high the team will consider recommending a power tool to minimize the time removing and placing fasteners.

R3.13 – Risers adding to the disassembly and assembly times was a concern for the team. The final design does not require interaction with the risers for both the assembly or disassembly tasks and thereby essentially diffusers the risk level making it Negligible.

R4.01 – The loss of efficiency in the pump is a concern for the team as it affects the overall performance of the pump. However, the redesign of the piping is outside the scope of the project and team will accept the existing risk level.

R4.02, R4.03 – Repositioning of the tank was a significant risk factor as it caused the need for investment of high levels of time and resources. However, the engineering analysis and the cost/benefit analysis steered the team away from repositioning the tank and thereby diffused the risk level to Negligible.

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Final Engineering Specifications for Design Considerations

Meeting SpecificationsThe project is highly likely to meet 18/22 target specifications as outlined in the Table except Spec # 1, Spec # 15, Spec # 16 and Spec # 18. Here, Spec # 1 is a high priority specification; Spec # 15 & Spec # 16 are moderate priority and Spec # 18 is low priority.

The team is highly unlikely to meet the requirements of Spec # 1. The engineering analyses of the current designs show that the team is not in a position to achieve a level of efficiency between 60% and 100%. Furthermore, the team does not foresee any design changes in the volute, impellers or diffuser that will meet the target specification. If possible, the team will consult with the customer to revise the target specification.

The team is concerned about meeting Spec # 15, Spec # 16 and Spec # 18, which deal with the interaction of the Graphic User Interface and the Motor Control Module. Therefore, measuring and controlling the motor parameters from the GUI is not currently possible. The team has added the required materials (DB9 to RJ45 adapter cable, Serial communication port replicator card) to the BOM and will begin repairing the GUI/Motor Control connection as materials become available. The team has planned to assign adequate time and resources to achieving these specifications and is moderately confident of success.

ConclusionThe team will be following the action items spreadsheet as well as the engineering analysis spreadsheet to complete all needed items by the end of MSD1. The designs, based on any feedback during the design review, will be finalized and sent to be machined, so as to reduce the lead time before the queue becomes long. Most parts can be machined at RIT in the Brinkman Machining Center, but there is no five-axis CNC at that facility, so the more complicated designs

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will have to be outsourced to local machine shops in Rochester. Typical lead times were found to be two weeks, which is satisfactory for a tentative deadline for component testing during the first few weeks of MSD2, if designs are submitted for machining before finals week. Thank you for your feedback.

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Appendix A: Impeller and Diffuser Design Equations

inDRPM

inD

QD

BladesBlades

CrCt

inftCr

ftCr

inftCt

ftCtUCr

UCt

GPMQin

galinQ

inftQ

ftininftft

ininQ

BUDQ

ftU

inBinD

1907.1

))1750)((

sec875.85(533.1

)(533.1

80825.696.0

tan

2.77

tan

sec35.34sec8625.2

)sec9.22)(125.0(

sec14.151sec595.12

sec)/9.22)(55.0(

3.22

)min

sec60)(2311

(sec875.85

sec875.85sec156.0

)12625.0)(125.0)(sec9.22)(

124(

sec9.22

625.0 470 125.0 55.0

1

31

602

3

1

31

1

2

3

2

23

2

2

2

2

2

2

2

2

3

3

33

222

2

22

2

23

sec43.10070cos

cos82.86

sec93.10sec71.196

tan

sec71.196

)70(tansec93.10)825.0)(12)(sec9.22(

sec93.10)625.0)(4(

sec875.85

tan

75.54

tansec12.77sec128.109

0 costan

tan

sec12.774

1907.1sec875.85

)4(

sec128.1092

)1907.1)(sec3.183(2

2

22

3332

3

3

2

2

3

2

2222

222

11

1

11

1

1

1

2

3

1

21

1

1

1

11

inC

CrC

BDCQ

in

in

inCt

inft

inftCt

ininin

inCr

CrUCtBD

QCr

rm

min

in

rm

CU

inC

in

inC

DQC

inU

inradU

DU

24

N s=N∗Q

12

H3

4

H=2. 31(P )s . g.

s .g .h 20=. 999H=11. 56 ft @5 psi

N s=1750∗5gpm

12

11. 56 ft34

N s=949. 1

N s=(1750)∗22. 3gpm1/ 2

9. 457 ft34

N s=1532→NewPumpN s

Appendix B: System Fluid Mechanics Analysis

Figure 1: Existing System

25

Figure 2: Proposed System

26

Appendix C: Full Risk Assessment

27

28

29

Appendix D: Vibrations Analysis

30

Appendix E: Riser Drawings

31

Appendix F: Impeller and Diffuser Drawings

32

33

34

35

36

37

Appendix G: Fastening Analysis

38

39

Appendix H: Pump Housing

Back Housing

40

Volute:

Front Housing: