review of components analysis aerospace engineering, international school of engineering (ise)...
TRANSCRIPT
![Page 1: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/1.jpg)
Aircraft Propulsion 1
Review ofComponents Analysis
Aerospace Engineering, International School of Engineering (ISE)Academic year : 2012-2013 (August – December, 2012)
Jeerasak Pitakarnnop , [email protected]@nimt.or.th
November 17, 2012
![Page 2: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/2.jpg)
Aircraft Propulsion 2
Component Analysis
• Diffuser– Free Stream to Diffuser Inlet– Diffuser Inlet to Outlet
• Nozzle– Fixed Divergent Nozzle– Diverging Converging Nozzle
• Axial Flow Compressor• Axial Flow Turbine
November 17, 2012
![Page 3: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/3.jpg)
Aircraft Propulsion 3
Engine without Inlet Cone
• Free Stream to Diffuser Inlet• Subsonic Flow• Supersonic Flow with Shock
• Diffuser Inlet to Outlet• Ideal Diffuser – Isentropic Flow• Non Ideal Diffuser – Fanno Line Flow
November 17, 2012
![Page 4: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/4.jpg)
Aircraft Propulsion 4
Free Stream to Diffuser Inlet
November 17, 2012
πo represents loss from free stream to the inlet.
Subsonic Flow• πo ≈ 1 (= 1: ideal isentropic flow)
Supersonic Flow Shock• πo < 1
![Page 5: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/5.jpg)
Aircraft Propulsion 5
Supersonic Flow with Normal Shocks
• Shocks usually occur exterior to, or near, the inlet plane of the diffuser when an aircraft flies supersonically.
• The strongest shocks is the normal shocks.
Oct. 13, 2012
![Page 6: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/6.jpg)
Aircraft Propulsion 6
Ex 1: Normal Shocks
A standing normal shock occurs on an aircraft flying at Mach 1.50. The internal recovery factor of the diffuser is 0.98, and the specific heat ratio is 1.40. Find the total recovery factor of the diffuser.
Oct. 13, 2012
![Page 7: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/7.jpg)
Aircraft Propulsion 7
Ideal Diffuser
November 17, 2012
Isentropic & Adiabatic Flow• Constant Total Pressure
pta = pt1 = pt2
• Constant Total TemperatureTta = Tt1 = Tt2
(hta = ht1 = ht2)
![Page 8: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/8.jpg)
Aircraft Propulsion 8
Isentropic Flow
Oct. 13, 2012
Mach Number and Local Speed of Sound
Stagnation Relations
Area Ratio
![Page 9: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/9.jpg)
Aircraft Propulsion 9
Limit on Pressure Rise
Separation is one of the limits of the diffuser operation.
Oct. 13, 2012
Aligned Inlet Flow:
for flow without separation.
Mis-Aligned Inlet Flow:Upper limit on the pressure coefficient will be
reduced appreciably to perhaps 0.1 to 0.2.
![Page 10: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/10.jpg)
Aircraft Propulsion 10
Ex 2: Separation Limit
Design an ideal diffuser to attain the maximum pressure rise if the incoming Mach no. is 0.8. That is find the diffuser area ratio, pressure ratio and the resulting exit Mach number. Assuming isentropic flow and γ = 1.4.
Oct. 13, 2012
![Page 11: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/11.jpg)
Aircraft Propulsion 11
Non Ideal Diffuser
November 17, 2012
To quantify loss from the free stream to the diffuser exit, we introduce:• Total Pressure Recovery Factor:
where• πr is the diffuser pressure
recovery factor, and• πo represents loss from free
stream to the inlet.
High Speed/Flow decelerates/Pressure increases
Low Speed/Flow accelerates/Pressure decreases
Nearly Adiabatic Flow, assume:• Constant Total Enthalpy
hta = ht1 = ht2
• Constant Total TemperatureTta = Tt1 = Tt2
![Page 12: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/12.jpg)
Aircraft Propulsion 12
Friction Flow
Viscous flows are the primary means by which total pressure losses occur!!
Fanno Line Flow: flow with friction but no heat transfer
Fanno Line Flow could be used when:• Exit-to-inlet area ratio is near unity,• The flow does not separate.
Oct. 13, 2012
![Page 13: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/13.jpg)
Aircraft Propulsion 13
Fanno Line FlowAdiabatic Flow of a Calorically Perfect Gas in a Constant-Area Duct with Friction
Oct. 13, 2012
![Page 14: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/14.jpg)
Aircraft Propulsion 14
Engine with Inlet Cone
• Oblique Shock–Oblique Planar Shock–Oblique Conical Shock
• Mode of Operation–Design Condition–Off Design Condition
November 17, 2012
![Page 15: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/15.jpg)
Aircraft Propulsion 15
Oblique Planar Shocks
• 2D planar shock is simpler than conical shock.• Occur when an inlet is attached to the
fuselage of the aircraft, the inlet is more or less rectangular, resulting in planar shock.
• Flow behind the planar shock is uniformly parallel to the wedge.
Oct. 13, 2012
![Page 16: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/16.jpg)
Aircraft Propulsion 16
Oblique Planar Shocks
Oct. 13, 2012
δ = deflection angleσ = shock angle
![Page 17: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/17.jpg)
Aircraft Propulsion 17
Oblique Conical Shocks
• Found in many aircraft applications.
• A conical ramp is used to generate an oblique shock, which decelerate flow to a less supersonic conditions.
• A normal shock further decelerates the flow to a subsonic condition for the internal flow in the diffuser.
Oct. 13, 2012
Spike on BlackBird
![Page 18: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/18.jpg)
Aircraft Propulsion 18
Oblique Conical Shocks
Oct. 13, 2012
![Page 19: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/19.jpg)
Aircraft Propulsion 19
Oblique Conical Shocks
Oct. 13, 2012
![Page 20: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/20.jpg)
Aircraft Propulsion 20
Oblique Conical Shocks
Oct. 13, 2012
![Page 21: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/21.jpg)
Aircraft Propulsion 21
Modes of Operation
Oct. 13, 2012
Design Condition: the oblique shock intersects the diffuser cowl All the air that cross oblique shock enters the engine
Flow rate decreases Pressure in the diffuser decreases Mach no. in the diffuser decreases Shock is pushed out!!
Flow rate increases Pressure in the diffuser drops Shock moves into the diffuser
Shock is stronger larger total pressure lossSome of the air will be spilled high pressure additive dragShock is used to compress air outside shock wasting power
Acting like a supersonic nozzle Shock occurs in diverging section with high Mach no. More total pressure is lost.
![Page 22: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/22.jpg)
Aircraft Propulsion 22
Mass Flow or Area Ratio
Oct. 13, 2012
True ingested mass
Mass flow enters the engine
Reference Parameter
Mass flow ratio
![Page 23: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/23.jpg)
Aircraft Propulsion 23
Design Operation
November 17, 2012
![Page 24: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/24.jpg)
Aircraft Propulsion 24
Off-Design Operation
When the diffuser operated at off-design conditions, the area should be varied so that it operates efficiently.
Oct. 13, 2012
In the case of a single planar oblique shock:
Inlet area could be determined from:
![Page 25: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/25.jpg)
Aircraft Propulsion 25
Ex 3: Supersonic Diffuser
A diffuser with a spike is used on a supersonic aircraft. The freestream Mach number is 2.2, and the cone half-angle is 24°. The standing oblique shock is attached to the spike and cowl, and a converging inlet section with a throat of area Am is used to decelerate the flow through internal compression. Assume γ = 1.4 and πr = 0.98.
a. Estimate πd on the assumption the inlet starts. Also, find the required Am/A1
b. Find πd on the assumption the inlet doesn’t start and has a standing normal shock located in front of the spike.
Oct. 13, 2012
![Page 26: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/26.jpg)
Aircraft Propulsion 26
NozzleFixed Diverging
Nozzle
November 17, 2012
Converging-Diverging Nozzle
![Page 27: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/27.jpg)
Aircraft Propulsion 27
Primary Nozzle
In real analysis: Pexit may not match Pa due to incorrect nozzle area proportion. Frictional losses are include but adiabatic process still be assumed.
Nozzle Efficiency
Constant cp
Specific heat
Exit Velocity
Adiabatic
Oct. 20,2012
![Page 28: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/28.jpg)
Aircraft Propulsion 28
Primary Nozzle
Adiabatic Process Flow: For the ideal case, isentropic process
Adiabatic
Thus,
Oct. 20,2012
![Page 29: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/29.jpg)
Aircraft Propulsion 29
Primary Nozzle
Choke condition:
Then,
If p* > pa, the nozzle is chokeIf p*= p8, M8 = 1If p* < pa , M8 < 1 and p8 = pa
Oct. 20,2012
![Page 30: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/30.jpg)
Aircraft Propulsion 30
Converging Nozzle
Oct. 20,2012
Exhaust of converging nozzle with matching exhaust and ambient pressures
Exhaust of under expanded converging nozzle
![Page 31: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/31.jpg)
Aircraft Propulsion 31
Converging-Diverging Nozzle
Oct. 20,2012
![Page 32: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/32.jpg)
Aircraft Propulsion 32
1st – 3rd Condition of CD nozzle
• Case 1: pexhaust = pambient and Subsonic Flow Through out the nozzle.
• Case 2: pexhaust = pambient and Subsonic Flow Through out the nozzle but Mthroat =1.
• Case 3: pexhaust = pambient , Subsonic Flow in the converging section and Supersonic Flow in the diverging section. – MAXIMUM THRUST– Design Condition for the ideal case
Oct. 20,2012
![Page 33: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/33.jpg)
Aircraft Propulsion 33
4th Condition of CD Nozzle
• pambient is slightly above the designed pexhaust
– Result in a complex 2D flow pattern outside the nozzle
Oct. 20,2012
Considered as “Overexpanded Case”• The flow suddenly is compressed
and decelerates outside the nozzle.
• A series of compression waves and expand waves are generated.• Can be calculated basing on 2D
compressible flow
![Page 34: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/34.jpg)
Aircraft Propulsion 34
5th Condition of CD Nozzle
• pambient is below the designed pexhaust
– Result in a complex 2D flow pattern outside the nozzle
Oct. 20,2012
Considered as “Underexpanded Case” or “Super Critical Case”• The flow continues to expand and
accelerates outside the nozzle.• A series of compression waves and
expanded waves are generated resulting in a series of shock diamonds.
![Page 35: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/35.jpg)
Aircraft Propulsion 35
6th Condition of CD Nozzle• pambient is significantly above the designed pexhaust
But below the 2nd case– Result in a single normal shock or a series of oblique
and normal shocks called λ
Oct. 20,2012
Also “Overexpanded Case”• Result in a subsonic exit Mach no.: LOW THRUST Totally
undesirable
![Page 36: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/36.jpg)
Aircraft Propulsion 36
7th Condition of CD Nozzle
• pambient is significantly above the designed pexhaust
Limit condition of the 6th case– Exit pressure causes a normal shock exactly at the exit
plane– Case 4 falls between case 7 and 3.
Oct. 20,2012
![Page 37: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/37.jpg)
Aircraft Propulsion 37
Ex4: Converging-Diverging Nozzle
A converging-diverging nozzle with an exit area of 0.2258 m2 and a minimum area of 0.1774 m2 has an upstream total pressure of 137.895 kPa. The nozzle efficiency is 0.965 and the specific heat ratio is 1.35. a. At what atmospheric pressure will the nozzle
flow be shockless?b. At what atmospheric pressure will a normal
shock stand in the exit plane?Oct. 20,2012
![Page 38: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/38.jpg)
Aircraft Propulsion 38
Axial Flow Compressor
November 17, 2012
![Page 39: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/39.jpg)
Aircraft Propulsion 39
Velocity Polygon
November 17, 2012
![Page 40: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/40.jpg)
Aircraft Propulsion 40
Total Pressure Ratio
• Power Input to the Shaft
October 27, 2012
• Total Pressure Ratio of the Stage
The equations is derived for a single stage (rotor and stator) using 2D planar mean line c.v. approach.“Midway between hub and tip”
Control Volume definition for compressor stage
![Page 41: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/41.jpg)
Aircraft Propulsion 41
Percent Reaction
A relation that approximates the relative loading of the rotor and stator based on the enthalpy rise:
October 27, 2012
![Page 42: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/42.jpg)
Aircraft Propulsion 42
Relationships of Velocity Polygons to Percent Reaction and Pressure Ratio
October 27, 2012
![Page 43: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/43.jpg)
Aircraft Propulsion 43
Limit on Stage Pressure Ratio
• The rotor is moving, the relative velocity must be used:
October 27, 2012
• For the stator, which is stationary the relative velocity must be used:
1 and 2 refer to the stage inlet and midstage properties.
![Page 44: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/44.jpg)
Aircraft Propulsion 44
Limit on Stage Pressure Ratio
Rotor
October 27, 2012
Stator
![Page 45: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/45.jpg)
Aircraft Propulsion 45
Axial Flow Turbine
November 17, 2012
![Page 46: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/46.jpg)
Aircraft Propulsion 46
Velocity Polygon
November 17, 2012
![Page 47: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/47.jpg)
Aircraft Propulsion 47
Velocity Polygon
November 17, 2012
![Page 48: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/48.jpg)
Aircraft Propulsion 48
Total Pressure Ratio
• Power Input to the Shaft
November 17, 2012
• Total Pressure Ratio of the Stage
The equations is derived for a single stage (rotor and stator) using 2D planar mean line c.v. approach.
“Midway between hub and tip”The continuity, momentum and energy equations are used for the delivered shaft power:
![Page 49: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/49.jpg)
Aircraft Propulsion 49
Percent Reaction
A relation that approximates the relative loading of the rotor and stator based on the enthalpy rise:
November 17, 2012
![Page 50: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/50.jpg)
Aircraft Propulsion 50
Relationships of Velocity Polygons to Percent Reaction and Pressure Ratio
November 17, 2012
![Page 51: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/51.jpg)
Aircraft Propulsion 51
Turbine and Compressor Matching
1. Select operating speed.2. Assume turbine inlet temperature.3. Assume compressor pressure ratio.4. Calculate compressor work.5. Calculate turbine pressure ratio required to
produce this work.
November 17, 2012
![Page 52: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/52.jpg)
Aircraft Propulsion 52
Turbine and Compressor Matching
6. Check to see if compressor mass flow plus fuel flow equals turbine mass flow; if it does not, assume a new value of compressor pressure ratio and repeat step 4, 5, and 6 until continuity is satisfied.Note: No need to do the iteration in the exam, I will provide a required values to determine other value.
November 17, 2012
![Page 53: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/53.jpg)
Aircraft Propulsion 53
Turbine and Compressor Matching
Note: No need to do the iteration in the exam, I will provide a required values to determine the others from compressor and turbine performance maps.
Ex. For given rotational speed, mass flow rate and total pressure ratio across each component, efficiency could be determined.
November 17, 2012
![Page 54: Review of Components Analysis Aerospace Engineering, International School of Engineering (ISE) Academic year : 2012-2013 (August – December, 2012) Jeerasak](https://reader038.vdocument.in/reader038/viewer/2022110103/56649f0c5503460f94c1fe7d/html5/thumbnails/54.jpg)
Aircraft Propulsion 54
Good Luck!!!
November 17, 2012