The Effect of Number of Steps on the Performance of a Cascade Type Solar Still

The purpose of this study is to simulate fluid flow in a weir-type cascade solar still, assuming steady-state and air being the ideal gas and incompressible. The commercial software FLUENT is used for numerical simulation of the process. SIMPLE algorithm is used to calculate the relationship between pressure and velocity. In addition, first order upwind method is applied for separation of displacement and interpolation of pressure. Numerical simulations are performed for Solar Still with four to ten and also with twelve steps. Results of investigations on a Solar Still with different number of steps, in which the height of the steps is constant value of 2 cm, show that increasing the number of steps causes to increase water production up to eight steps. Furthermore, the highest rate of water production was 232 ml/m3hr for solar still with eight steps.