Development of Heat Transfer Model at Intake System of IC Engine with Consideration of Backflow Gas Effect

Abstract

Improving thermal efficiency of internal combustion engines has been a priority in the automotive industry. It is necessary to model the heat transfer phenomenon at the intake system and precisely predict intake air’s mass flow rate into the engine cylinder. In the previous studies, the heat transfer at the intake system was modeled as quasi-steady state phenomenon, based on Colburn analogy. Authors developed two empirical equations with the introduction of Graetz and Strouhal numbers. In the present study, further improvements were done by the addition of pressure ratio between the intake manifold and atmospheric pressure, along with Reynolds number in order to characterize the backflow gas effect on intake air temperature. Compared with the experimental results, maximum and average errors of intake air temperature estimations inside the manifold found to be 2.9 % and 0.9 %, respectively.