The Effect of Various Test Parameters on the Steady Flow Test Results of a Four-Valve Spark Ignition Engine: A Tentative Approach toward Standardization

The present paper is an account of an experimental analysis carried out to investigate to what extent the flow characteristics in the intake system of a 4-valve, spark ignition internal combustion engine depend on the experimental conditions at the steady flow test bench. In this respect, the study is aimed at determining the influences of the intake adaptor, test pressure, adaptor length and diameter, adaptor roughness, paddle wheel diameter, and asymmetric valves lifting on the flow coefficient and the swirl intensity measurements. In studies of this kind, researchers generally tend to adopt different test parameters to arrive at a nonuniform base to compare results from several investigations. This work is aimed at verifying the quantitative differences detected using these test parameters. The findings revealed that the swirl intensity depends on the pressure test, adaptor length, and the entry type to a significant degree. Moreover, it was observed that the intake adaptor is the most effective test parameter on the flow coefficient. Finally, the sensitivity analysis has been performed in order to investigate the experimental results and to correlate them with the test parameters.