The view factor plays a major role in
6.4. Adhikari et al.’s model 
Adhikari et al. argued that SCH-900776 the Dunkle’s relation is valid only when the Grashof number is less than 2.51×105 and needs to be modified for higher values of the Grashof number. They performed a simulation experiment to evaluate the amount of water evaporated in a solar still under steady state conditions in a controlled environment. They suggested the following relation to estimate the hourly distillate yield directly such as,equation(70)mew=αn(ΔT′)(Pw−Pgi)mew=α(ΔT′)n(Pw−Pgi)whereequation(71)ΔT′=(Tw−Tg)+(Pw−Pg)(Tw+273.15)268.9×103−Pw
The value of α is sieve plates a constant for a particular operating range of a solar still. If the operating temperature range is changed, then a different value of α is required for the estimation of hourly yield. Table 1 gives the value of α for different water temperature of the solar still and for different Grashof numbers.
Values of α for different water temperatures and Grashof numbers.Water temperature (°C)α×109Gr<2.51×105Gr>2.51×105408.12029.7798608.15189.6707808.18959.4936Full-size tableTable optionsView in workspaceDownload as CSV