Domed roofs have been used in Iran and many other countries to cover large buildings such as mosques, shrines, churches, schools, etc. However their favorable thermal performance has allowed them to be employed in other buildings like bazaars, or market places in Iran.In this investigation, wind pressure coefficients were determined experimentally for a domed roof model in a boundary layer wind tunnel. The model was a 1/10 scale model of the dome of an old school in the city of Yazd, in the central desert region of Iran. The model included a number of windows at the collar of the dome, and a hole on its apex. A total of 48 pressure tabs were employed to measure the air pressure at various points on the dome model. Tests were run under three conditions of windows and the hole on top of the dome being open or closed.The result of this research can be used to determine the heat transfer coefficient of wind blowing on domed roofs and the passive cooling effect of such structures.

Stagnation flow freezing of saturated air vapor in an axisymmetric cylindrical coordinates system is considered. It covers a detailed discussion on how the ice layer and the ongoing phenomenon changes with time. The fluid along the z-direction, with strain rate  impinges perpendicularly on a substrate flat plate and because of the lower plate temperature than the freezing temperature of the water, condensation has occurred, and then water probably starts to freeze. The flow is assumed laminar with constant properties and the density changes with temperature can be negligible. The momentum equations are converted to an ordinary differential equation by use of appropriate similarity transformations. The obtained ordinary differential equation is solved by using the fourth-order Rung_Kutta Method. Two methods have been used to solve the energy equation: finite-difference numerical techniques and similarity solutions. The results of the energy equations of these two methods are compared together for validation. Based on the obtained results, substrate plate temperature for initiation of water vapor freezing is reduced by the reduction of far-field saturated air temperature. Interestingly, the freezing start time increases with the increase of far-field saturated air temperature first and then reduces rapidly as the increase of the far-field temperature is continued. The ultimate thickness of the ice is also presented. One of the most important achievements of this paper is determining the final thickness of ice in an analytical manner using only the air temperature profile, which can be used as a reliable method to validate the numerical solution.

Flow regime in dam's bottom outlet is divided in pressurized flow and free surface flow by the gate located for discharge control. Down stream tunnel involves high velocity Multi component Air -water flow studied by mathematical model. In this research work, we used Finite volume mixture two phase flow model. Because of high Reynolds number, standard two equations k-ε turbulence model was used. Model was verified by backward-facing step flow and results have been compared with experiments founded by Durst and Schmitt. Air demand ratio has been determined as function of Froude number at contracted section. Flow patterns have been compared at two categories of slug & stratified flows, Air mean concentration profile has been obtained at down stream tunnel. Comparison of flow pattern at two case with and without of aeration was investigated. Pressure drop behind of the gate and formation of vortex flow after the gate section have been discussed. Measurement of flow discharge and determination of contraction coefficient of the gate was outlined.

Considering the risk of infection in surgeries, maintaining an acceptable indoor air quality in the operating rooms (ORs) to ensure the health and safety of patients and surgical team is very essential. Since airflow is one of the primary mechanisms for transmitting of infections and pollution, it is crucial to examine the air distribution systems in the ORs. In the present study the effect of turbulent and laminar airflow (TAF/ LAF) systems on the air and CO2 distribution in an OR was examined. The effects of inlet and outlet configurations were evaluated for seven different models. The results indicated that the LAF systems is superior over TAF systems. Based on the findings, the LAF with the air curtain configuration brings about the minimum CO2 concentration level in the OR. The results showed that LAF with the air curtain model is able to decrease the CO2 concentration by about 64.66% and 88.96% on central plane, which passes along the body patient on 1.14 m and 1.7 m above the floor, respectively compared to the existing model.