Aston Martin MSc Project Summary
First, a quick summary of my MSc project. During my year at Oxford Brookes University I designed, built and tested a 1:18 scale aero package for an Aston Martin V8 Vantage, again specifically to compete within the Britcar regulations. The standard road car was evaluated and an aero kit designed, optimised and tested - with the aim of increasing overall downforce as efficiently as possible. The baseline was found to have a Drag Coefficient (Cd) = 0.335 and a Lift Coefficient (Cl) = 0.322 (positive!!). The aero kit reversed the positive lift of the standard car to Cl = -0.314 for an increase in the Cd of only +0.08. Some of the more interesting pictures from the project are included below:
Well, there's a lot of research that can carry over from this project such as the wing profiles used, optimum attack angles etc. More on this later though, let's get back to the Z3 aero work.
CFD Study 1 - Open Top or Closed Top?
The first thing I wanted to look at was the effect of running the car with and without the hardtop, in terms of overall drag and the behaviour of the airflow over the car. Leaving the car without a roof would save a lot of weight and lower the car's centre of gravity, but is it really as simple a decision as that? As per Le Mans prototypes I suspected the closed top car would perform better aerodynamically, but it's always good to put numbers on things!
Look at the smooth uniform flow over the closed top compared to the open top. It's all going on, with flow re-circulating, flowing upwards and even forwards!
Engineering is always about compromise, very rarely do you get something for nothing in this game. It's a no-brainer though that I'll have to go with the hard top at the expense of high-up weight (raised CoG), manufacture time and cost. I've already got an OEM hardtop but it weighs a ton, so I'll make my own light-weight composite version at some point. This is what it's all about though and by evaluating your options you can make an informed engineering decision based upon your overall project aim i.e building a race car to be as quick as possible!