A generalized sidewall air inlet (SWAI) was designed based on past research (Wu et al., 1994; Hoff et al., 1994). Research was conducted on this SWAI design to evaluate volumetric flow rate as a function of inlet height, opening height, hood design, deflecting vane-design, and static pressure difference across the inlet. Dimensional analysis was used as a tool to decide the importance of each inlet parameter. Extreme values of Pi terms were calculated, tested, and compared with each other to analyze the significance of inlet parameters affecting the discharge coefficient and volumetric flow rate. Results showed that the discharge coefficient ranged from 0.58 to 0.90 and was affected by the opening aspect ratio, weather hood approach angle, and deflecting vane angle. Design graphs are presented for evaluating the discharge coefficient for this generalized inlet.