Numerical Investigation of Geometric Factors for Design of High Performance Air-Jet Pumps Using in Vehicle-Mounted Vacuum Toilet
Air-jet pump as the pneumatic source of a vehicle-mounted vacuum toilet provides the vacuum to pump the fecal sewage out of toilet bowl via the compressed air passing through the pump under certain pressure. In this study, Computational Fluid Dynamics (CFD) technique is employed to investigate the effects of three important air-jet pump geometry parameters: the primary Nozzle Exit Position (NXP), the constant-area section length (L1) and the diffuser diverging angle (θ), on its performance. A CFD model is firstly established according to 1D analytical method, and then used to create 135 different air-jet pump geometries and tested under different operating conditions. The significance of this study is that these findings can be used to guide the adjustment of NXP, L1 and θ to obtain the best air-jet pump performance when the operating conditions are different.
F. Gao et al., "Numerical Investigation of Geometric Factors for Design of High Performance Air-Jet Pumps Using in Vehicle-Mounted Vacuum Toilet", Advanced Materials Research, Vols. 268-270, pp. 46-50, 2011