advanced - openvspopenvsp.org/wiki/lib/exe/fetch.php?media=workshop20:... · 2020. 9. 23. ·...

NNX09CC86P SBIR Review, Presented to NASA, July 7th, 2009OpenVSP Workshop 2020 Sept. 15th – Sept. 17th

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Empirical Systems Aerospace, Inc. www.esaero.com

VSPAERO GUI & Tutorial - Advanced

Presented by:

Justin Gravett

[email protected]

Empirical Systems Aerospace, Inc. (ESAero)

mailto:[email protected]


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Agenda

• Panel Method

• VSPAERO Advanced Options

• Cp Slicer

• Control Surfaces & Grouping

• Rotor Disks

• Propellers (Unsteady Analysis)

• VSPAERO API

• Unsupported Advanced Features

• Demo


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• Toggle Panel Method on

Overview tab

• Preview VLM Geometry

disabled

• 3D mesh representation of

input geometry

– Use VSPAERO GUI to

generate Cart3D file

• Cart3D file name override on

Advanced tab

• Actuator disks not included

• Do not include control surface

groups

Panel Method


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Advanced Case Setup

• File name set when model is

saved – override available

• Set Num CPU to the number of

physical CPU cores

• Batch calculation– OFF: Flow conditions executed one

by one – separate result files

– ON: All flow conditions executed at

once – grouped in result files

• Use X-Z symmetry to speed up

symmetric cases

• Preconditioner– Matrix (default), Jacobi, and SSOR

– Influence on robustness & speed

• 2nd Order KT Mach Correction

• Write 2D FEM - output *.fem2d

file for structural calculations

(e.g. Beam3D)

GUI – Advanced Tab (1/3)


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Wake

• Wake iterations (Num It.)– Solution convergence and

execution time

– Marginal return past default

– Used for steady analysis

• Wake Nodes: Number of wake

points in solution

• Fixed Wake: No iterations

Other

• Clmax, Max Turning Angle– Coarse methods to globally limit

the lift from the inviscid solution

• Far Field Dist. – Ability to set distance to freestream

• Ground Effect Dist.– Enable ground effect at input

distance

– Rotates vehicle by alpha about CG


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Propeller Representation

• Actuator disk or rotating blades

analysis representations– Activates Disk or Propeller tab

Run Mode

• Stability Type– Enable finite differencing for aero

coefficient derivatives

– Num cases = 7+ ncontrols

• Single axis unsteady p, q, & r

analysis available

Advanced Flow Conditions

• Available for actuator disk,

unsteady, and stability analysis

• VRef & MachRef– Hover analysis: set Vinf to 0 and

VRef to rotor tip speed

• ReCref – Re along ref. chord


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Cp Slicer

• Runs vspslicer program on

VSPAERO *.adb output

• Define 2D cutting planes

– Slice Type -> Normal axis

– Position along normal axis

• dCP for VLM, CP for Panel

• Slice VSPAERO *.adb file

– Activate for next VSPAERO run

– Slice previous VSPAERO run

Cp Slicer


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Cp Slicer Results

Slice

Selection

X-Axis Plotting

for Slice Types

Flow Condition

Selection

Legend

Manual

Axis Limits


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GUI – Control Grouping

User Groups

• Groups are analogous to

control “channels” that can

deflect multiple surfaces

• User defined or auto grouped

Available Control Surfaces

• Available Control_Surf or

Rectangle types for each group

• One control surface for each

reflected copy

• Highlighted red when available,

green when grouped

Deflection Gains

• Gains multiplied by group

deflection angle

• Flip sign for symmetric surface

– cancel roll moment (elevator)

Auto Group → EASY Button


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GUI – Control Grouping Workflow

1. Add a control surfaces

2. VSPAERO GUI → Control

Grouping Tab

3. Add new group

4. Rename group [Optional]

5. Select Surfaces

6. Click “Add Selected”

2

51

3

46


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6. Click surface to highlight on

geometry

7. Set deflection gains as

needed

8. Set Deflection on Overview

Tab

9. Launch Solver

10. Check lift distribution for

expected results

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6

7

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GUI – Rotor Disks

Rotor Disk Element Settings

• Requires a “Disk” surface– Disk Custom Geom

– PropGeom in Disk mode

• Select Actuator Disk

representation on Advanced tab

• Lists all disk settings in the

model

• Vinf & Rho apply to all disks

(Advanced tab)

• Hub Diameter, RPM, CT, & CP

specific to each disk

• Selected disk highlighted red


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GUI – Propellers (Unsteady Analysis)

Overview

• Time dependent analysis

• Requires a Prop Geom

• Select Rotating Blades

representation on Advanced tab

• Vinf & Rho apply to all propellers

(Advanced tab)

Time Settings

• Automatically calculate time step

for 20 deg turn of slowest prop

• At least 5 full revolutions

recommended

• Manual time step options


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GUI – Propellers (Unsteady Analysis)

Advanced

• Hover Ramp

– Initial flow velocity

– Reach steady state more

quickly

• From Steady State: Initialize

unsteady solver from steady

solution

Noise Analysis

• Generate output files for

PSUWOPWOP

– Next or previous run case

• Noise type and length unit inputs

Propellers

• Set individual or uniform RPM

• Selected propeller highlighted

red


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Unsteady Results

Data

Selection

Flow

Condition

Selection

Legend

Manual

Axis Limits

Group/Rotor

Selection

Data Type

• Plots *.history,

*.group.*, &

*.rotor.* files


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• Plots *.lod and

*.rotor output

file

• Blade loading

averaged

across all time

steps

Unsteady Results

Data Type


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API Documentation

• VSPAERO run in API through the Analysis Manager

– "VSPAEROComputeGeometry“ – Generate VLM DegenGeom or Panel Method *.tri

– "VSPAEROSinglePoint“ – Single flow condition

– "VSPAEROSweep“ – Multiple flow conditions

• VSPAERO API results stored and queried through Results Manager

• VSPAERO Actuator Disk and Propeller Functions

• VSPAERO Control Surface Group Functions

Angelscript Examples

• “CpSlicer.vspscript”

• “Master_VSP_VV_Script.vspscript”

• “TestAnalysisVSPAERO.vspscript”

• “VSPAERO_UnsteadyProp.vspscript”

• “VSPAERO_ActuatorDisk_CSGroup.vspscript”

• Swept Wing API Example

VSPAERO API

*See OpenVSP API & MATLAB/Python Integration Presentation

http://openvsp.org/api_docs/latest/group___v_s_p_a_e_r_o_disk_and_prop.html

http://openvsp.org/api_docs/latest/group___c_s_group.html

https://github.com/OpenVSP/OpenVSP/tree/master/examples/vspaero_ex/Swept_Wing_API


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Unsupported Advanced Features

Flow Field Query

• Add the following to the *.vspaero input file and run from command line:

NumberofSurveyPoints = n

1 x1 y1 z1

2 x2 y2 z2

3 x3 y3 z3

4 x4 y4 z4

......

n xn yn zn

Isolated Rotor Analysis

• -rotor input argument: rotates frame instead of geometry

• See “Isolated_Rotor” example in “vspaero_ex”

Unsteady Analysis of Complex Motion

• Can specify velocity & acceleration vector, mass, & inertia matrix

• Must create *.groups input file manually


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Demo

advanced - openvspopenvsp.org/wiki/lib/exe/fetch.php?media=workshop20:... · 2020. 9. 23. ·...

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