Search Results

Hydro-pneumatic suspension systems have been used increasingly in recent times because of the well known advantages they offer. It is equally well known that the spring force is time- and temperature dependent, resulting in varying ride height and ride comfort of vehicles equipped with hydro-pneumatic suspension systems. In the present study, the temperature- and time dependent characteristics of hydro-pneumatic springs are modelled mathematically. This is done in order to investigate the effect of heat transfer on the spring characteristic so that it can be taken into account during the design of such systems. The mathematical analysis is based on the solving of the energy equation of a gas in a closed container by using the Benedict-Webb-Rubin equations for real gas behaviour. This differs from the traditional method which makes use of the ideal gas approach and polytropic processes to determine the spring characteristic.