Influence of clean side duct topology on mass air flow for gasoline engine on passenger vehicle

The need for effective control systems is exacerbated by tighter pollution regulations. Also, there is growing demand for highly efficiently vehicles especially in the passenger segment. The air flow estimation of engine and accordingly controlling the fuel quantity removes many lacunas of the modern gasoline engines. The hot wire type mass air flow sensor is commonly used for air flow measurement, and is generally mounted in clean side piping to prevent damage to air mass flow sensor. The right estimation of air flow is possible by getting uniform flow over the different engine operating speed and load conditions. The placement of air flow sensor becomes critical considering the engine layout and packaging constraints and meeting the sensor mounting requirements. The deviation in mounting of air flow sensor will lead to consequential impact on engine performance and emissions. In our new developed air intake system for passenger vehicle application, torque oscillations were observed over engine operating speeds and load conditions. The air flow oscillations and signal were further evaluated to understand the issue. The detail study of air flow signal was carried out over different engine operating range with air filter box layouts. In this paper, extensive work was carried out to understand impact of air flow signal variation. The different air intake layouts were evaluated along with sensor mounting to minimise signal disturbance to get proper estimation of air flow. The detailed study with final air intake system was finally evaluated.