Due to population growth and pollution, the demand for pure water has increased steadily over the years. As membrane distillation operates primarily with low-grade heat, it may be a viable solution to the problem. This paper examines the integration of direct-contact membrane distillation integration with solar collectors to generate clean water. Using mathematical modeling and numerical simulation, the optimal operating conditions for Direct contact membrane distillation under varying solar irradiance flux conditions are determined. Heat transport mechanism, mass transport mechanism, and fluid flow behavior are analyzed using the effectiveness-NTU method. The most important system parameter, mass flux is evaluated for different cities of India throughout the year, the flow behavior for low and high solar flux. It is recommended to operate the system under a laminar regime during periods of low-temperature gradient, i.e., low solar irradiance, particularly in the morning and evening. However, when there is a high-temperature gradient, i.e., a high solar irradiance flux, it is recommended to operate the system under a turbulent regime, particularly at midday. It is observed that when the flow changes from laminar to turbulent flow there is an increase of 7 to 18% in mass flux has been observed.