Abstract
KEYWORDS – heat transfer, spark ignition engines, thin film sensor, experiments, signal processing
ABSTRACT –
Engine optimization requires a good understanding of the in-cylinder heat transfer which implies accurate heat transfer measurements. A better understanding will lead to improved heat transfer models for use in simulation tools. This work shows a new measurement technique based on Thin Film Gauges to measure the in-cylinder heat flux. In this work, an inlet valve of a Volvo 1.8l engine is instrumented with several Thin Film Gauge heat flux sensors. The implementation and sensor measurement technique is discussed. The TFG sensors are used to study the incylinder heat transfer phenomena under motored conditions and an initial fired operation measurement is also performed. The analysis makes use of calculating the convection coefficient which characterizes the convective heat transfer. The effect of the manifold air pressure and engine speed on the peak heat flux is studied in a systematic way using Analysis of Variance in motored operation. Furthermore, the spatial variation in heat flux measured with the Thin Film Gauge sensors is investigated.