Urban crossings are important component of the cities. They may cause one of the most important health problems for humans. The buildings which are conforming urban crossings, are decreasing fresh wind heavily. Urban crossings are the main source of pollution in the city caused by traffic and other human activities. Creating thermal comfort especially in the marginal cities of the deserts could improve the life quality. How we can solve this problem effectively? By natural wind flow. To understand the relevant procedures, it is necessary to understand the main currents at first. The forms of buildings should be used as a passive strategy in order to improve air conditions, in addition to morphology of the city. The wind behavior could be investigated confronting different kinds of buildings in different scales (from city scales to residential units and interior design.) some of the elements are considered in the urban scale and have an effect on block building. Then, the investigation should be according to urban and the neighborhood scale. The current research question is that utilizing the block forms in marginal cities of the Deserts in Iran how affect using natural wind for creating thermal comfort? In this research plaques of newly build parts of the city are based on the confirmed descriptive plan for the city to investigate the effects of the relevant parameters changes in wind flow formation and have an effect on creating thermal comfort of the urban outdoors. Research tools are CFD like Ansys Fluent and Autodesk CFD and making maquettes and doing test in wind tunnel in order to simulate natural air flow. Finally, a comparative study showed the effect of different forms of urban contexts on thermal comfort and help to propose the utilized block form.
