Search Results

Cooling of low-drag cars can be very sensitive to front-end air management in hot environments. An iterative simulator of a car-engine-radiator system is presented which predicts the radiator temperature at idle after a heat soak. The procedure uses information gained under laboratory conditions at lower than boiling temperatures which is then used for thermal stability predictions. An estimate of the stored energy in the engine-bay at high temperature is needed. The procedure offers a reasonably simple way of computer prediction of the coolant temperature of a radiator system and assessing the sensitivity of the various parameters. It also offers the potential for less testing-time in the environmental wind tunnel. The analytical simulator appears to behave correctly in response to known state changes. Other than simulating one condition in a car, its ability to satisfactorily predict other conditions for other cars has not been established.

Recently aerodynamic devices have become larger to reduce aerodynamic drag. Some structural problems have been experienced when attached to lightweight cabin roofs. On-road and wind-tunnel tests are presented to document the forces generated by the devices to provide information to the truck and device manufacturers. Two-component transducers measured vertical and horizontal loads at device attachment points and for one test a truck front axle was strain gauged. Data were recorded under a range of road conditions, including rough roads and heavy braking, on a Mercedes Benz V2244 prime mover fitted with a Rudkin-Wiley roof fairing and an International Harvester Australia (IHA) “S” series prime mover fitted with a Fuelscoop roof fairing. The results showed that dynamic loads arising from the road roughness are causing structural problems rather than the aerodynamic loads. It was concluded that a low mass device with a carefully designed support system is required.