This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Implementation and Validation of Active Aerodynamic Force Control During Race Vehicle 7-Post Testing
Abstract:
The typical approach for body load simulation during 7-Post testing has been to match body motion and forces for a known suspension setup condition, and then to maintain the applied body loads for subsequent tests with different setups. However, in order for the test to remain valid across a wide range of vehicle setups, the applied body loads may need to be varied to match the specific test car. A significant component of the body load comes from aerodynamic downforce, which can be calculated during a 7-Post test based on vehicle body position and previously recorded wind tunnel test data. This paper discusses a method to generalize the 7-Post inputs by updating the aerodynamic force content automatically during each test run.
The paper begins by discussing validation of an active aerodynamic force control scheme on a MTS 320 7-Post road simulator with a NASCAR Sprint Cup vehicle. Testing included comparing loads on the rig with wind tunnel loads, verifying the ability of the simulator to input the desired loads, and measuring the response to vehicle setup changes.
The paper concludes that the active aerodynamic control method accurately replicates the relationship between vehicle body position and aerodynamic loads during 7-Post testing. The simulator control scheme correctly adapts to changes in body position by adjusting the aerodynamic loads to match previously measured static wind tunnel data. This method for 7-Post testing is expected to allow more accurate prediction of vehicle response due to suspension setup change, as well as more accurate overall prediction of track performance. The new 7-Post control scheme has been found to be an improvement in testing methodology by more capably replicating expected on-track vehicle response.