I thought it would be good to share a project I have been working on. Although the Z4M is one of the best looking cars on the planet it always struck me as looking a little bit mild for an m-car. In my eyes the front especially could do with a little bit more CSL/GTS, a bit more aggression. There are several parts already on the market but the design, quality, functionality or price was something I felt was lacking. I therefore decided to design and create my own.
Last year a Stateside friend of mine who is involved with reverse engineering used photogrammetry to reconstruct his car. This involves using several hundred overlapping pictures to generate a point cloud. It took me several months to reconstruct the various external surfaces on the car.
Having these external surfaces available in CAD allows me to perform computational fluid dynamics analysis (CFD) and assess the performance of new designs. The CFD model includes all reasonable detail such as rotating wheels/discs, moving ground, underfloor and a portion of the engine bay. The latter allows me to check the influence on radiator mass flow. The fluid volume is divided up into millions of hexahedral elements. To get the most from the simulation with the available resources it requires simplification in tight and overdetailed areas. The pictures below show the various parts/sub-assemblies and a close up of the individual mesh elements.
The simulation matches quite well on drag in spite of some of the simplifications. It already highlights some nice avenues for front splitter and canard development. Below a picture of the pressure distribution on the surface.
It would be great if you could share your feedback, experiences or thoughts.
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- Update 1 : First front diffuser iteration, page 1 post #8
- Update 2 : Centre extension and endplate detail, page 1 post #12
- Update 3 : First canard iteration, page 1 post #17
- Update 4 : Canard endplate and underbody splitter length, page 1 post #18
- Update 5 : Raised central splitter, page 1 post #20
- Update 6 : Biplane canard, page 2 post #24
- Update 7 : 3D scanning, page 2 post #32
- Update 8 : Final canard design, page 2 post #35