Predicting Vehicle Turbocharged Diesel Engine Performance at Altitude

A method is developed for predicting vehicle turbocharged diesel engine performance over a broad range of altitude and ambient temperature at constant fuel rate and engine speed. This method contains the calculation for changes in turbocharger characteristic with varying ambient conditions, and reflects the compensation offered by turbocharging system for reducing air inlet density at altitude, and is simple without involving engine thermodynamic cycle simulation. Using this method with engine performance and turbocharger characteristic measured at some ambient condition, the engine performance and turbocharger characteristic at desired altitude and ambient temperature can be predicted.

The calculations are carried out for two vehicle turbocharged non-intercooled diesel engines by using this method, and are validated by comparing the calculated and experimental results.

The effects of altitude up to 6000 meters and within a ambient temperature range of 258- 318 K on vehicle turbocharged diesel engine performance are predicted.

Applications of this method have proved that it is a convenient analytical tool in the study and correction for turbocharged diesel engine performance at altitude.