Ferrouillat et al. [29] reported that longitudinal vortices are generated on quasi-steady phenomena. The present model is derived based on continuum flow approach and steady-state conservation equations of mass, momentum and energy. The deionized-water flow is assumed incompressible and due to the low inlet velocity and the small winglet pitch the flow is assumed to be laminar. Moreover, radiation and gravity effects are ignored in this study. The resulting governing equation can be written as follow
Mathematical models