Thermal comfort is an important component of health-related urban well-being (UrbWellth) of the urban population. Outdoors in sunny conditions the human thermal environment is strongly influenced by radiation fluxes, which are often expressed as a mean radiant temperature (Tmrt). In an urban environment Tmrt is, especially in sunny conditions, strongly influenced by the building morphology due to shading and reflection of radiation. To model these morphological effects within an urban system model for UrbWellth, a simple model for Tmrt is required that simplifies the actual urban environment to reduce computational costs but still considers the most important aspects of Tmrt variability within a city. To do so, within this paper the open-source and modular Simple Urban Radiation Model (SURM) is presented. SURM is validated with respect to different calculation methods of both view factors and radiative fluxes as well as to radiation modification by buildings. The results indicate that SURM models radiative fluxes and radiative influences of buildings sufficiently accurate to be applicable as one component of an urban system model for sunny conditions.

热舒适性是与城市人口健康相关的城市福祉（UrbWellth）的重要组成部分。在阳光充足的户外条件下，人的热环境受到辐射通量的强烈影响，辐射通量通常表示为平均辐射温度（Tmrt）。在城市环境中，由于辐射的阴影和反射，特别是在阳光充足的条件下，Tmrt受建筑物形态的强烈影响。为了在城市系统模型中为UrbWellth建模这些形态效应，需要一个简单的Tmrt模型，该模型可以简化实际的城市环境以减少计算成本，但仍要考虑城市中Tmrt变异性的最重要方面。为此，本文提出了开源的模块化简单城市辐射模型（SURM）。SURM已针对视角因子和辐射通量的不同计算方法以及建筑物的辐射修正进行了验证。结果表明，SURM对建筑物的辐射通量和辐射影响进行了足够精确的建模，可以用作晴天的城市系统模型的一个组成部分。