Numerical study of the steps height and glass cover angle effect on the heat transfer performance for solar distillation

Productivity and heat transfer in the stepped solar still by varying the glass cover angle and steps height were investigated numerically. Mass, momentum, energy, and diffusion equations were used for simulating the distillation process in order to obtain the productivity and heat transfer coefficient. Further,the numerical simulation validated by existed experimental data. Simulation results indicated the highest freshwater production in comparison with experimental set up condition, which is at the step height 4cm and glass cover angle 60.23◦, belongs to the step height of 5.5cm with 1400 mL/m2hr, namely 91⁒ increase and much less for the step height of 1cm with 350 mL/m2hr, namely 52⁒ decrease. Most increase in Nusselt number obtained for the angle of 55◦ with Nu=12.03 with 29⁒ increase and much less for the angle of 65◦ with Nu=8.16 with 12⁒ decrease. In addition, most and less variation of the heat transfer coefficient obtained for the step height of 5.5cm with hc=4.04 W/m2 K, with 39⁒ increase and for the step height of 1cm with hc=2.18 W/m2 K, with 24⁒ decrease, respectively.