INFLUENCE OF GAS-DYNAMICAL NONSTATIONARITY ON LOCAL HEAT TRANSFER IN THE GAS–AIR PASSAGES OF PISTON INTERNAL-COMBUSTION ENGINES

The results of experimental investigation of the effect exerted by gas-dynamical nonstationarity on the intensity of heat transfer in the intake and discharge manifolds of piston internal-combustion engines are presented. Experimental setups, instrumentation, and experimental procedures are described. Combined dependences of the change in the instantaneous fl ow velocity and in the local coeffi cient of heat transfer in the gas–air passages on the engine crank angle are analyzed. It is shown that the gas-dynamical nonstationarity reduces the local heat transfer intensity in
the gas–air passages of piston internal-combustion engines 1.3–2.5 times depending on the gas fl ow velocity (on the mode of engine operation). A method is suggested to account for the gas-dynamical nonstationarity by applying a correction coeffi cient of heat transfer mobility to the classical equations used for calculating the local heat transfer coeffi cient.
   
Author:  L. V. Plotnikov and B. P. Zhilkin
Keywords:  local heat transfer, gas-dynamical nonstationarity, gas fl ows, intake manifold, discharge manifold, gas exchange processes, piston internal-combustion engine.
Page:  1444