Construction of a Diesel Engine Test Stand and a Crank Angle Based Heat Release Model

Abstract

A test stand for a light duty diesel engine was constructed and used to measure both mean and crank angle based engine operating parameters. The test stand features a 1.1L Hyundai CRDi turbo-diesel engine, a Land and Sea Dynamometer, and requisite instrumentation. Measured operating parameters include temperature (ECT, oil, EGT, intake air), mass air flow, manifold pressure, air-fuel ratio, engine speed, and load torque. Crank angle resolved measurements include in-cylinder pressure, injector current, and fuel-rail pressure. In-cylinder pressure traces were used to calculate rate of heat release (ROHR) curves for specific engine loads and speeds. A heat release estimation model was then calibrated using the experimental ROHR curves and expanded to handle multiple fuel injections per cycle. A comprehensive engine model was created that includes estimation of heat release, heat transfer to the surrounding cylinder, thermodynamic properties of the cylinder, engine geometry, and input fuel and air quantities. The model provides the pressure, temperature, gross heat release and heat transfer rate, cumulative gross heat release and heat loss on a crank angle basis. Other model outputs including indicated work, indicated torque, brake torque, and indicated specific fuel consumption (ISFC) per cycle were calculated and compared with dynamometer results.