Investigation of PMV index in thermal comfort of urban open spaces in spring, case study: sidewalk river side Khorramabad

Nowadays, the issue of thermal comfort has been raised as one of the important factors in the quality of urban spaces along with physical factors, so that not paying attention to it, causes these spaces not to be used and confined so that a space where all physical factors to use It has citizens in it, it is not used due to not considering thermal comfort. In fact, it can be said that observing the thermal comfort of open urban spaces is also important for the use of citizens and should be taken into consideration. On the other hand, due to the impact of various factors and parameters in urban open spaces that affect the thermal comfort of users and the lack of codified principles in this field has made it difficult for designers to identify and meet climatic needs in an urban area. The present study, considering the discussion of thermal comfort in urban sidewalks, investigates climatic and environmental factors in the area in which this study is located in the city of Khorramabad and in the area of ​​the celestial sphere and through the application of energy simulation technique by software. Envy Matt, which is an application software in the design of open urban spaces according to climatic conditions, uses an analytical method to study the thermal comfort index (PMV, average vote prediction), which is one of the important indicators in measuring thermal comfort in spring, and In the end, the results obtained in the simulation, which includes all different parts of the sidewalk, showed that factors such as choosing the direction of the sidewalk, the width of the sidewalk, the presence of trees, shade and water, and walking time in terms of thermal comfort. The sidewalk has been impressive.Optimal public and open urban space can be the bedrock of various positive effects on the city. One of the positive effects that increases people's face-to-face meetings are sidewalks. The consequence of this effect is an increase in social interactions. Accordingly, urban spaces are the arena of human interaction in which the story of collective life is opened, a space in which all people can be present and active (Lang, 1987). Riversides are a type of sidewalks that are necessarily formed on the banks of rivers, and for this reason, their special geographical location and their proximity to the fluid nature of the river, puts riverbanks in the group of sidewalks with special qualities. The presence of citizens in two groups of cavalry and pedestrians and different speeds is another feature of riverside spaces. Flexible nature, gentle breeze, soft stretches, dense vegetation, wide landscape and bright light and various colors all create an energetic atmosphere that is perfected by the presence of different groups of people.Although determining all the factors affecting rivers is a significant task, "climate and environmental comfort" seems to be much more effective. Thermal comfort is the condition in which the comfort of a thermal environment is provided for humans (Hansen, 1990). Cremona mentions comfort as a basic need in public space, noting that without comfort, it is difficult to find how other needs of space can be met (Carmona, 2007). Therefore, the equilibrium relationship between the presence of people and having climatic and environmental comfort to create a public and open urban space can play an effective role because public space that can not provide comfort is less used and even avoided (Lenzholzer). , 2012). Field studies on the Khorramabad River show that factors such as "temperature" and "radiation" are among the climatic factors that increase the spatial quality of the river.The issue of increasing the quality of various urban spaces has always been a significant issue for urban designers. Due to the close interaction between the man-made environment and the pristine nature, the rivers are a suitable place to join these spaces to other functional spaces of the city and the possibility of greater productivity and continuous presence of citizens in this part of the city.The purpose of this study is to investigate the climatic and environmental comfort of sidewalks in Rudkenar in order to find the factors that have the greatest impact between humans and the environment in open urban spaces and ultimately increase the presence in these spaces, which is the purpose of this study. The need for this research is also due to the fact that open urban spaces are a large part of the city that are often used with very practical functions such as sales, access to indoor and semi-open spaces and passenger traffic. The use of urban open spaces as a place for recreation, leisure and relaxation is an approach that, along with other uses, increases the presence of citizens.1-1. Problem definition and research backgroundIn recent decades, several models have been defined to estimate the energy balance of the human body in different environments to assess thermal comfort. Most of these models include meteorological components and environmental reflection (Fanger, 1972). In addition to meteorological components, the models also include the average radiant temperature, which plays an important role in the heat balance of the human body in summer and in urban environments. This temperature shows the effect of radiant energy from the environment on the exchange of radiation between a person and the surrounding environment (Heidarinejad and Delfani, 2009). Among the researches done on thermal comfort in open urban spaces can be a research entitled "Microclimate and thermal comfort in open spaces of sidewalks" by Patvin and Ahmad Omar (Ahmad Amr Patvin, 2007) with the aim of examining different urban spaces in order to evaluate Thermal comfort conditions in Quebec, Canada were performed on three open spaces in Boston, a dense commercial area and a high-rise urban area. In this study, urban morphological characteristics such as height and height, porosity, density