Altitude cooling investigation of the R-2800-21 engine in the P-47G airplane II : investigation of the engine & airplane variables affecting the cylinder temperature distribution

摘要

The data obtained from cooling tests of an R-2800-21 engine installed in a p-47G airplane were studied to determine which engine and airplane operation variables were mainly responsible for the extremely uneven temperature distribution among the 18 engine cylinders obtained at the medium and high engine-power conditions. The tests consisted of flights at altitudes from 5000 to 35,000 feet for the normal range of engine and airplane operation. The results of the study showed that a flow condition in the induction system associated with the wide-open throttle position, which affected either the fuel air or charge distribution, was primarily responsible for the uneven temperature distribution. For the range of fuel-air ratios tested (0.080 to 0.102), the temperature distribution remained essentially unchanged. The individual effects of thrust-axis inclination, cowl-flap opening, and quantity of auxiliary air were found to be secondary in importance. At low angles of throttle opening, engine speed was found to have little effect on the temperature pattern.