Evaluation of Variables Influencing Air Cooling of Engines 350118
TO convert cooling results observed under one set of conditions to equivalent values for other conditions, a better understanding of some of the many variables involved is needed. The progress of experiments being conducted along several lines with this objective in view is reported.
Published data on heat-transfer research have been examined and, from these, a working approximation relating air temperature and mass flow has been set up.
Single-cylinder engine and full-scale testing have been conducted to evaluate this equation as applied to modern baffling conditions.
Tests to observe directly the effect of cooling-air temperature-variation on cylinder-wall temperatures under specified conditions have been made.
The effect of carburetor-air temperature on cylinder-wall temperatures at constant manifold pressure has been experimentally determined.
A method of obtaining an indication of velocity through the baffle passages which is accurate under any condition of installation is described.
The volume of cooling-air flow through the baffle passages of a Cyclone engine is calibrated against readings of a baffle-flow indicator.
Other variables still require evaluation. The results obtained thus far are submitted for the use of others concerned with this problem.