A Alipour - Corresponding Author Address: Mechanical Engineering Department, Shiraz University, Shiraz, Iran
S.M.A Najafi - Corresponding Author E-mail: mohamadalinajafi۲@gmail.com

Cisterns are ancient building having two main tasks. First task is storing water in raining seasons for using in dry seasons and the second task is decreasing water temperature, which happens because of the air flow above water surface and evaporating water. It can be stated that by increasing fluid flow above the surface, evaporating increase so increasing in heat transfer happens and decreasing of water temperature is the result. This paper has investigated fluid flow around and inside cisterns with FLUENT software results.Increasing in air flow demand to the cistern is the primary purpose of this study, by changing main parameters of cistern geometry like increasing or decreasing of doom hale diameter, inlet and outlet of wind catcher, elevation of wind catcher and also wind speed. This study introduces the best geometry for cisterns according to maximum air flow demand and minimum volume. Considering that, there is a direct relation between heat transfer and airflow rate in cisterns, so in this study, the influence of mentioned parameters are investigated to reach optimum design for the best performance of cisterns.

Cistern, air flow, optimization, geometry, Thermal performance