The effect of the solar wall heating on the flow structure within the cross-ventilation of isolated building

In this paper a comprehensive study is conducted on the heat transfer between building and the atmosphere within a cross ventilation situation, this situation is characterized by a transverse flow between the two parallel windows of an isolated building.  The study is divided into two parts, in the first part, the effect of the walls, solar heating during the day (windward between sunrise and noon, the roof at the moon and leeward between noon and sunset) on the air temperature distribution and air velocity inside and outside an isolated building is studied when a numerical simulation is conducted in an atmospheric micro scale. For the second part, the study is focused on the effect of temperature change of the building floor, by an external heating source such as a recessed serpentine, on cooling or heating the air but in this case only inside the building by numerical simulation. The numerical results are validated using experimental measurements (velocity profiles and turbulent kinetic energy) of Y. Tominaga realized at Niigata Institute of Technology in Japan, these measurements provide a very useful database for validation of numerical models of computational fluid dynamics (CFD). Compared to those wind tunnel experimental measurements, the numerical results of the cross-ventilation show a good agreement. The detailed results analysis shows that the differential heating of all building surfaces can greatly influence the capacity of the flow to transport and exchange heat

The effect of the solar wall heating on the flow structure within the cross-ventilation of isolated building

In this paper a comprehensive study is conducted on the heat transfer between building and the atmosphere within a cross ventilation situation, this situation is characterized by a transverse flow between the two parallel windows of an isolated building.  The study is divided into two parts, in the first part, the effect of the walls, solar heating during the day (windward between sunrise and noon, the roof at the moon and leeward between noon and sunset) on the air temperature distribution and air velocity inside and outside an isolated building is studied when a numerical simulation is conducted in an atmospheric micro scale. For the second part, the study is focused on the effect of temperature change of the building floor, by an external heating source such as a recessed serpentine, on cooling or heating the air but in this case only inside the building by numerical simulation. The numerical results are validated using experimental measurements (velocity profiles and turbulent kinetic energy) of Y. Tominaga realized at Niigata Institute of Technology in Japan, these measurements provide a very useful database for validation of numerical models of computational fluid dynamics (CFD). Compared to those wind tunnel experimental measurements, the numerical results of the cross-ventilation show a good agreement. The detailed results analysis shows that the differential heating of all building surfaces can greatly influence the capacity of the flow to transport and exchange heat

Structure of the out- flows behind buildings and Influence of the geometry of the streets on the out-flows

This paper intends to study the latest results from the research methods available with special intentions given to the architectural effects of the street valley and wind speed. Extensive research has been carried out through several research approaches to understand the effect of wind flow formation in the streets and the current wind condition on the structure of the wind current. The main goal of this paper is to study the structure of out- flows of buildings and the effect of street engineering on external flows. The numerical modeling is to simulate the effect of the wind flow and the layer limit on different building structures using the ANSYS Fluent package. The program was based on the K-ε model to incorporate the potential of differential equations forming the mathematical model. Three cases were considered; the first case is the height-to-width ratio of the valley (h/w), the second is the width of the dome (b3/b) and the third case the ratio of the height of the valley (h3/h) to see the effect of street valley engineering and wind speed effect

Comparison between numerical models and CHENSI with experimental data (MUST) within the case of the 0° approach flow.

The MUST wind tunnel data set served as a validation case for obstacle-resolving micro-scale models in the COST Action 732 “Quality Assurance and Improvement of Micro-Scale Meteorological Models”.The code used for the numerical simulation is code CHENSI, simulations carried out showed a certain degree of agreement between the experimental results and those of the numerical simulation, they highlight the need for proceeding to an experimental campaign but with more measurements and the need for having a good control of determining factors in the exploitation of its results. The aim is to explain the experimental data obtained by atmospheric wind on the physical model. The site company of Mock Urban Setting Test (MUST) was selected to be simulated by the code CEN CHENSI developed by the team of Dynamique of l’atmosphere Habitee of LME/ECN. The code was based on (K- ε) model of (Launder and Spalding). For the integration of the PDE (Potential Dimensional equations) constitute the mathematical model, the finite volume method of (Ferziger and Peric) was used within the decade disposition of unknowns MAC of (Harlow and Welck) for the discretisation of PDE terms. The boundary conditions were imposed according to the wall laws (In ground and on buildings) or within Dirichlet condition (Inlet boundary) or of Newman (Outlet boundary or top limit). The numerical domain used was comparable to the one of the atmospheric wind experiences within a three-dimensional Cartesian mesh. Numerical results presented in this study for the mean flow field, turbulent kinetic energy in the direction of wind incidence 0°. For an objective comparison of the CHENSI model performances within other European codes used for MUST configuration simulation. The results obtained by the numerical modelling approach are presented in this paper