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A radio telemetry system has been designed and developed at Durham University that enables surface pressure data to be transmitted from a rotating racing wheel to a host PC, where data post-processing is carried out. A multi-element wheel rim has been designed to allow the telemetry system to be located inside a pneumatic tire. Surface pressure distributions around the centerline of the wheel show good agreement with previous research. A flow field investigation has also been conducted, downstream of the wheel, for both stationary and rotating wheel cases. The results presented highlight some of the key features of the flow field and give confidence in the telemetry system.

The aerodynamic forces induced on a generic ‘hatchback’ model have been measured as it passes through a perpendicular cross-wind jet generating a relative yaw angle of 30°. This has been done in the unique University of Durham automotive wind tunnel, which utilises the stationary model approach, with the cross-wind being introduced by means of a second jet which is separated from the main jet by a moving belt and aperture assembly. Data acquisition was by means of an array of surface pressure tappings. Transient pressure force and moment coefficients have been measured and it is shown that the side and lift forces experienced in the transient situation exceed the steady state values at corresponding yaw angles by between 10% and 20%.

An improved technique is described for the experimental modeling of transient cross wind gust influences on passenger vehicles. The new configuration uses a set of vertical axis shutters which open and close in a ‘Mexican wave’ fashion to scan the cross wind jet along the working section of the wind tunnel. The new arrangement dramatically increases the rate at which experiments can be performed and offers the opportunity to apply phase-averaging techniques to multiple data sets in order to reduce noise. This is a significant development as most previous test methods have suffered from poor signal to noise ratios. Experimental results are presented for transient surface pressure measurements on a simplified vehicle model which clearly demonstrate the benefits of the new technique.