Numerical Investigation of Effective Parameters on Drag Force Estimation Using Momentum Defect Method

Researchers have recently paid a lot of attention to drag force estimation over different bodies. This force is usually calculated using surface integral over the body and momentum defect method in the wake region. In this research, the steady-state, incompressible drag force calculation around a submarine model is numerically investigated using the latter technique (momentum defect method). Simulations were carried out at different aspect ratios at zero angle of attack and the capabilities of this method at inclined flows were also investigated. The most important parameters which affect the results are the vertex space, the distance of data collection section, and the data collection section size. In this article, practical suggestions are made for each parameter. The contribution of the pressure, momentum, and turbulence term were also evaluated at different cross sections. These findings can be implemented in wind tunnels with small test section length. They can also be used to compare the results with the common CFD surface integral method. By using the results of this research, the maximum error implementing this technique at zero and non-zero angle of attack will be about 4% and 16% respectively.