NAVAIR 4.0M.1.5

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

Presented to:

Presented by:

NAVAIR Use of OpenVSP

1

OpenVSP Workshop

AJ Field

29 Aug 2017

AIR-4.0M

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

Agenda

• Agenda – Role of NAVAIR Conceptual Aircraft Design – Our Design Tool Framework – How we use OpenVSP now – Future plans for using OpenVSP

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

Effectiveness • Sets of System

Capabilities • Combat Speed • Payload • Radius • etc

Design • System Attributes for

each Set • Engine Type • Construction

Materials Composition

• Fuel Burn Rate • etc

Cost • System Cost for each

Set • Development • Flyaway • Operating • Life Cycle • etc

Feasibility Assessment New Aircraft Models

Role of Government Design

File: NAVAIR Brief 3

Decision Maker • Effectiveness vs Cost • For Feasible System

Capability Sets

In-house conceptual design work informs pre-milestone A requirements refinement and S&T studies

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

MAOIE

File: NAVAIR Brief 4

Lift & Drag Estimates

Weight Estimates

Propulsion Estimates

Single Geometry Result

3D Geometry OpenVSP

Mission Performance

MMPAC

Point Performance

MAOIE Geometry

Aircraft Design Variables

Engine Design Variables

MAOIE: Multidisciplinary Analysis and Optimization Integration Environment

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

OpenVSP Enables Wide Trades • MAOIE uses OpenVSP during wide tradespace

exploration – Millions of geometry variations – MAOIE gets updated geometry measurements for

each variation • Surface areas, Cross-Section areas, Volumes • These measurements are used by parametric weight and

drag estimation modules • For configurations within the parametric dataset, these

methods are accurate to within 10%, but only if the geometry inputs are accurate

• OpenVSP enables wide configuration tradespace exploration while maintaining accurate geometry inputs

File: NAVAIR Brief 5

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

Parameters Measured • Parameters Measured from OpenVSP

– Fuselage Total Wetted Area – Fuselage Max Xsect Area – Inlet Longitudinal Length – Whole Aircraft Max Length – Whole Aircraft Xsect Area Distribution – Whole Aircraft Total Volume – Potential Fuel Volume

File: NAVAIR Brief 6

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

Input Visualization • OpenVSP also lets design engineers visualize

the geometry they are analyzing

File: NAVAIR Brief 7

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

2017 Geometry Process 1. Build a parametric

SolidWorks model for a baseline configuration

2. Build an OpenVSP model for the same configuration, “tune” it to match the SolidWorks measurements

3. Use the OpenVSP model for tradespace exploration

4. Model the selected point in the tradespace with SolidWorks

i. check to make sure internal layout and carrier suit constraints still met

File: NAVAIR Brief 8

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

OpenVSP Models • OpenVSP Link to MAOIE completed through

User Parms – The user builds any OpenVSP model they want, but

all models have a standard set of User Parmameters • The Linking and Advanced Linking in OpenVSP are used to

shape the geometry based on the user Parms • This allows many OpenVSP models without having to

recompile the MAOIE C# code

– The user adds the VSP3 file location into their MAOIE file

File: NAVAIR Brief 9

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

User Parms

File: NAVAIR Brief 10

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

OpenVSP Link • OpenVSP Link to MAOIE completed through

Python API – During a MAOIE run, the MAOIE (C#) code writes

the standard set of User Parm values to a JSON File, then calls a Python script • The same set of User Parms are always written out, although

some values may be left at zero

– The Python script reads the JSON file, then uses the OpenVSP Python API to send the User Parm values to OpenVSP

– The Python also calls the OpenVSP computation methods, and writes the outputs to a JSON for MAOIE to read

File: NAVAIR Brief 11

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

Impact • Even this initial use of OpenVSP is substantially

improving our ability to explore tradespace at the beginning of acquisition programs

• Using DoD HPC resources, we are running millions of geometry variations to understand the impacts of varying design requirements

• This wide tradespace exploration would not be possible without the flexibility and accuracy of OpenVSP

File: NAVAIR Brief 12

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

Future Plans • We have just scratched the surface of how we can

utilize OpenVSP • Over the next couple years we would like to take

advantage of OpenVSP for: – CG estimation – Ballpark carrier “spotting factor” estimates – VSPAero for performance and Stability & Control

analysis • CL vs alpha • Induced Drag

– CDmin, Wave Drag estimations – Linking to/from OpenVSP and MAOIE without pre-

built User Parameters • Visualization • Simplify initial creation of MAOIE files

File: NAVAIR Brief 13

Distribution Statement A – Approved for public release; distribution is unlimited, as submitted under NAVAIR Public Release Authorization 2017-611.

Questions?

File: NAVAIR Brief 14