sae comvec 2014 cfd expert panel - the adjoint solver
DESCRIPTION
A presentation given at the SAE COMVEC conference this year during the CFD expert panel. Focuses on the new adjoint solver that is part of the automotive CFD suite, Elements, from Streamline Solutions.TRANSCRIPT
THE ADJOINT SOLVERAngus Lock, Auto Research Center LLC
Eugene de Villiers, Streamline Solutions LLC
SAE INTERNATIONAL
Features
• Supports incompressible & compressible flows
• 2nd order accuracy
• Turbulence handling:
– Spalart Allmaras, k-eps, frozen turbulence
• MRF and porous media support
• Immersed boundary for interface tracking
• Multi-objective:
– forces & moments, uniformity, pressure loss, massflow split,
swirl, wall shear stress, etc
• No expert knowledge required
Adjoint Solver
2
SAE INTERNATIONAL
Overview
• Specify design space and inlet/outlet interfaces
• Define optimisation objectives
• Run single simulation
• Output optimised shape
Topology Optimisation
3
SAE INTERNATIONAL
Simple Duct
• Topology Optimisation
• Pressure loss minimisation
• Design space with obstacles
Topology Optimisation
4
SAE INTERNATIONAL
Simple Duct
• 50% Pressure Loss improvement
• Optimised shape:
Topology Optimisation
5
SAE INTERNATIONAL
Topology Optimisation
6
SAE INTERNATIONAL
Overview
• Multiple objective Functions employed
– Minimize pressure loss in domain
– Maximize flow uniformity through porous media
– Target flow split through outlets 3x33%
– (Reduce curvature)
– (Reduce volume)
Topology Optimisation
7
SAE INTERNATIONAL
Topology Optimisation
8
SAE INTERNATIONAL
HVAC Duct
• Final shape
• 30% reduction in
pressure loss achieved
• At the cost of
– slightly worse flow
uniformity through the
porous media
– slightly worse flow split
at the three outlets
Topology Optimisation
9
SAE INTERNATIONAL
Open Wheel Race Car
• Generic open wheel car shape
• Thanks to Samuel Silva for providing the model
• Symmetric model
• ~17M cells generated with helyxHexMesh
• RANS simulation
• Spalart Allmaras turbulence model
• Lift and drag force objectives
• Internal porous media uniformity objective
Shape Optimisation
10
SAE INTERNATIONAL
Shape Optimisation
11
SAE INTERNATIONAL
DRIVAER
• Generic car shape based on BMW and Audi cars
• Thanks to TU Munich for providing the geometry*
• Symmetric model
• ~7M cells generated with helyxHexMesh
• RANS simulation
• Spalart Allmaras turbulence model
• Lift and drag force objectives
* A. I. Heft, T. Indinger, N. A. Adams: Introduction of a New Realistic Generic Car Model for Aerodynamic Investigations, SAE
2012 World Congress, April 23-26, 2012, Detroit, Michigan, USA, Paper 2012-01-1068
Shape Optimisation
12
SAE INTERNATIONAL
Shape Optimisation
13
SAE INTERNATIONAL
DRIVAER
• Comparison of 2nd order accuracy (top) with former 1st
order (bottom) results
Shape Optimisation
14
SAE INTERNATIONAL
DRIVAER
• Comparison of 2nd order accuracy (top) with former 1st
order (bottom) results
Shape Optimisation
15
SAE INTERNATIONAL
Others
• Regional train
• Showing drag surface sensitivities (front of the train on the
right side, rear of the train on the left side).
Shape Optimisation
16
Front/Rear combined
SAE INTERNATIONAL
Future Work
• Integrated surface morphing
• Carat++ plug-in from FEMopt
• Revolutionary FEM based surface
morphing framework
– smart filtering & feature preservation
– proven performance
• Improved immersed boundaries
• Adjoint Turbulence
• Adjoint thermal and species
• Adjoint CHT
Adjoint Solver
17
SAE INTERNATIONAL
Questions?
Paper # (if applicable) 18