The Prediction of Heat and Mass Transfer During Compression and Expansion in I.C. Engines 760761

The mathematical equations describing the momentum, energy and mass exchanges in non-firing engine cylinders are described and solved. Attention is confined to laminar flow in axi-symmetric cylinders. Pressure development and velocity prediction, for plane cylindrical combustion chambers, compare favourably with experimental measurements for compression] and expansion in motored engines. At engine speeds less than 100 rev/min the piston motion induces a toroidal vortex during compression whose direction is not reversed on expansion. Conductive heat transfer at higher engine speeds, 600-1000 rev/min, adequately describes the gas-wall heat-transfer. Flow patterns are also predicted for a diesel-type bowl in piston configuration.