powerflow空气动力学教程.ppt

Aerodynamic Optimization of Heavy Trucks,Agenda,Project Process PowerFLOW Introduce Application Examples Customers,Exa Corporation Confidential,Exa Confidential,PS,P1,P2,P3,P4,M1D,P5,J1,Design/Styling,Vehicle Engrg/ Development,Body/Chassis Engrg,Prototype Build & Manuf.,Multiple Themes Narrowed to 3,Reference Model,Single Theme,Design Concepts,Design Intent CAD,Final Surface Sign-off,Upper Body - Aero Design Sensitivity,Reference Vehicle Testing,M1 Prototype Testing/Development,VP Prototype Testing/Development,Benchmarking,Clay Model/Prototype Testing/Development,Update Cooling Module,Underbody Panels,Component Detail Tuning,Wheels / Tires,Mirror Design,Preparation & M1 Build,Preparation & VP Build,Production Process & Tooling,Start Mass Production,VP,M1,Surface Freeze,Design Freeze,Engrg Complete,Vehicle Aerodynamics Product Development Process,Vehicle Evaluation & Development,Design,Target Setting,Strategy Development,Development of Production Facilities/Tooling,3,Upper Body - Solve Aero Problems to Meet Targets,Aero Devices / Deflectors,Grille Openings Provide Sufficient Cooling Flow,Exas Aerodynamics Digital Simulation Process,Theme Selected,Upper Body Freeze,Model Freeze,Agenda,Project Process PowerFLOW Introduce Application Examples Customers,Exa Corporation Confidential,Unique Technology,DIGITAL PHYSICS,DENSITY MOMENTUM ENERGY,Extended Lattice-Boltzmann Based Solver More Fundamental Approach Wider Range of Physical Validity than Navier-Stokes Complex fluids From micro to macro scales Time Dependent Inherently unsteady fluid mechanics Benefits Efficiency & scalability No significant artificial dissipation Fast, time dependent solver Robust & physical realization of boundary conditions Fully automated grid generation,“PowerFLOW contains a state-of-the-art turbulence model that has significant advantages. With this model, PowerFLOW gives extraordinary results for the most complex turbulent flows” Prof. Steve A. Orszag, Percey F. Smith Professor of Mathematics, Yale University,Exa Corporation Confidential,Simulation Process,Geometry Preparation,Case Setup,Simulation,Results Analysis,Modify Geometry,Typical Process,Faceted Model & Setup,Results,CAD,PowerFLOW,Grid,Setup,Simulation, 5 to 6 days for 1st result 1 day per optimization,Simulation,CAD &CFD Modules,CAD CFD,Agenda,Project Process PowerFLOW Introduce Application Examples Customers,Exa Corporation Confidential,Exa Corporation Confidential,Areas of Interest for Aerodynamic Optimization,Cabin front with corner vanes and bumper apron Roof spoiler Trim tab Side extender Tractor side panels Trailer flow guide Trailer side panels,Flow Impingement Increases Drag,Exa Corporation Confidential,Application Examples,3% Fuel Saving from Side Panels 5% Fuel Saving from Boat-tailing,Exa Corporation Confidential,External Aerodynamics Cabin Optimization (late Pre-SOP),Why PowerFLOW was chosen/used Traditional WT testing high effort and too late in process DNW Windtunnel 250k per week + MAN mandays + logistics Objectives Select best possible Deflector shape Cover the tractor/trailor gap best Get best-in-class TGA truck Impact Multiple deflector variants Drag reduced by 30 counts,Kambiz Salari, et al DOE Heavy Vehicle Systems ReviewApril 18-20, 2006,Exa Corporation Confidential,External Aerodynamics Cabin Optimization (late Pre-SOP),Savings and benefits 5% Fuel Savings Saving 1: Fuel 35 l/100km 150.000 km / p.a. 52.500 l 5% = 2.625 l 3.000 p.a. 3.000,- * 7 years = 21.000 total Saving 2: Time 800 l / fuel tank 2.200-2.400 km 3-4 stops refuels p.a. + extended range 100km,Motivation,Tyres with extra low rolling resistance 3-5%,Electronically controlled cooling fan 0.5-1.2 %,Side air deflectors 0.2%,Revised air conditioning 0.5 %,Improved air pressure supply 0.5-1.0 %,Front underrun protection (FUP) 0.2 %,Modified retarder 0.5%,Roof air deflector for high bodywork 3%,Kenworth Truck,Part of $15B PACCAR Group Focus on Delivering Value to Fleet Owners Reliant on Technology for Competitive Edge EXA / IBM Cloud Computing Early Stage Aerodynamic Optimization Average Fleet Saves $1M / Year,“We exclusively do our engineering and aerodynamics work in digital,“ Feight says. Put another way, theyre in it for the long haul.,/2009/02/19/technology/fortt_kenworth.fortune/index.htm,Peterbilt Truck,Also part of PACCAR Group Achieved 12% improved fuel economy Implementation of new “aerodynamic package” Each 1% fuel saving = $5,600 savings in fuel per year per truck ($2.30/gal at 130,000miles/yr),