Cooled Engine Experiments

The experimental part of the program is concerned with making detailed heat flux measurements in both conventionally cooled metallic engines and in ceramic coated insulated engines for the purpose of validating the in-cylinder gas phase heat transfer models which have been developed in this program.

In the experiments carried out on the conventionally cooled metallic engine (single cylinder Cummins NH engine), a detailed set of heat transfer measurements was made over a matrix of engine speeds and loads. This included the total heat transfer measured by a thin film thermocouple probe (Morel et al, 1987) and the radiation heat transfer measured using a fiber-optic two-color radiation probe (Wahiduzzaman et al, 1987). The data showed an excellent agreement with the previously developed models. This includes detailed variation of heat flux with crank angle and location in the combustion chamber shown in Figure 3 (the bowl location refers to a location on the head facing the piston bowl, while the crown location refers to a location facing the piston crown), and the dependence of peak heat flux on speed and load shown in Figure 4. Figures 5a and 5b show predictions of the operating conditions of Figure 3 carried out with two widely used

CRANK ANGLE , DEGREES

Figure 3. Heat flux at rated operating conditions in a cooled metal engine. Comparison of predictions of flow-based model to experimental data.

CRANK ANGLE , DEGREES

Figure 3. Heat flux at rated operating conditions in a cooled metal engine. Comparison of predictions of flow-based model to experimental data.

0 0

Post a comment