Abstract: Helloal pipes are used extensively in industrial applications and the secondary flow affects the various aspects of the fluid in them considerably. For this reason, many efforts have been made in this field and mostly focused on planar curved pipe flows. Furthermore, since the circular cross-section is a special elliptical cross-section, the researches of the flow in elliptical pipes must have more profound significant.In terms of tensor analysis technique, the Navier-Stokes equations in a curvilinear coord...