Project

Solene-microclimat

Goal: From 2006, I have coordinated the development of the urban microclimate simulation software SOLENE-microclimat.

Methods: Urban Climatology, Building Performance Simulation, Urban modelling

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Project log

Bisam al Hafiz
added 3 research items
In this century, the world is facing a rapid urban growth, most of them (about 4.9 billion) will live in urban areas. These changes increased the use of land and reduced the green areas. As a result, our cities will be warmer climates compared to their surroundings. One of the main reasons behind these changes is the changes in the construction materials, especially the high heat capacity of both building envelopes and urban areas. This study tries to find some suitable types of construction materials compatible with climate conditions in Iraq; to avoid the increase of buildings' facade temperature on a real case of the residential complex in Mosul city-Iraq. To conduct this assessment, Solene-microclimat simulation tool is used in: Identifying the effect of new construction materials on building’s facade temperature, Carrying out sensitivity analysis over a period of time to determine types of materials Carry out a comparison over selected materials types with respect to their thermal performance. The results of this study proved that the main influence of thermal performance of any either exterior or interior building surface is the material type, which depends on its effusivity. Regarding Solene-microclimat, it has contributed significantly to the selection process.
In this century, the world has already witnessed the biggest increasein its population in human history, which led to the increase of theuse of the land and shrinking green areas. The main concern of thepresent thesis is the city which is characterized by higher nighttimetemperature compared to rural areas. This phenomenon is known asan urban heat island (UHI). UHI leads to degraded comfortconditions both outdoor and indoor, and as a result, higher energyconsumption for cooling.One of the main reasons for the UHI is the materials used forbuilding envelope and urban areas. Many attempts have been madeto avoid UHI by using a new type of materials such as usingmaterials with high solar reflectance. In addition, these types ofmaterials help minimize energy consumption if used on an urbanscale. In our research, we address the building envelope designwith respect to its main types of construction materials as well as itslayer design and its shape to mitigate the urban heat island andachieve energy consumption reduction. The work is applied on oneof the important residential complexes in Mosul city – Iraq, which willbe constructed in many cities in Iraq. The weather of the Mosul cityis characterized by hot semi-arid climate. In summer, the climate isdry and extremely hot, whereas it is very cold and the temperaturesare down to below zero in winter. The main objective of this researchis to propose an appropriate building envelope design and designstrategy which provides high thermal performance regarding theexterior and interior surface temperature, high-level of indoor thermalcomfort with minimum energy needed, reduce the air temperaturedifference between the city and its surrounding rural area. It tacklessome important questions that are related to the case study: What isthe relation between the building envelope design and the followingaspects: 1. The external surfaces temperature of buildings andurban surfaces which lead to raise the air temperature, and finallycontribute to the UHI phenomenon, 2. The indoor surfacestemperature of buildings which influence the indoor thermal comfortand the energy needed to maintain this level of comfort?To answer the research questions, simulations have been achievedby using Solene-microclimat. From simulation results, it is shownthat it is possible to find different combinations of materials, formsand surface coatings to both to reduce the interior and exteriorsurfaces temperature and consequently, maintain indoor andoutdoor thermal comfort. We also show that the strategy can bedifferent depending on the surface exposure to the sun and theinteraction between surfaces. We propose a methodology to find thebest combination depending on the case study.
Marjorie Musy
added a research item
In a dense urban area, pavement watering could be a solution to mitigate the Urban Heat Island. So far, mainly experimental studies have been used to evaluate watering techniques. In this study, a soil model dedicated to pavement watering has been developed within the urban climate model SOLENE-microclimat. This watering model is presented and evaluated via a measurement campaign performed on an asphalt car park during warm days. The measurement campaign reveals that the surface cooling is mainly due to evaporation (80%). However, under warm conditions, the heat flux exchanged between the runoff water and the surface should also be modelled. Indeed, watering events are modelled through a runoff convective heat flux and a latent heat flux. The mean daily RMSE between estimated and observed surface temperature is 1.04°C, 0.86°C, 0.66°C, 0.35°C and 0.21°C respectively at the surface, 5 cm-, 10 cm-, 34 cm-and 50 cm-depths.
Marjorie Musy
added 3 research items
The main purpose of this study is to evaluate an urban soil model that will accurately reproduce the heat flux into urban soil, which has an influence on the urban heat island effect, for typical urban land use such as a car park. After a complete literature review, a sensitivity study is carried out on a large number of parameters: material properties, layer size, deep boundary condition, and convective heat transfer coefficient. The model's ability to reproduce heat conduction transfer is validated via a measurement campaign performed on an asphalt car park during hot days. The mean daily RMSE between estimated and observed surface temperature is 0.86°C, and 0.72°C, 0.58°C, 0.26°C and 0.13°C respectively at 5. cm-, 10. cm-, 34. cm- and 50. cm-depths. Performances obtained using different node distributions are discussed and compared with results from the literature. The model is more efficient than most of the other models applied under similar conditions. Finally, application of the proposed model on a yearly basis demonstrates that the accuracy loss caused by the decrease in the number of nodes is higher for clear and sunny days.
A full coupling between a CFD code, a thermo-radiative model and a building energy simulation model enables Solene-microclimat software to calculate both building thermal behavior and urban microclimate with the retroaction of buildings on microclimate. However, this full coupling is time consuming and it is legitimate to wonder if it is always necessary to perform such detailed simulations. In the framework of the MERUBBI project, simulations were carried out to answer this question. A set of simulations was designed to explore different kinds of configurations: three cities in France (Nantes, Paris and Strasbourg), three levels of density (from an isolated building to an implementation in the dense city center) and three kinds of buildings (an individual house in Paris, a residential building in Nantes and an office building in Strasbourg). To study the sensitivity of energy demand to the coupling detail, for each thermal flux at the external surfaces of the building, several levels of details were taken into account. For the impact of wind on convection, three modalities were considered: a constant convective heat transfer coefficient, calculated from the wind velocity at 10m; a convective heat transfer coefficient calculated from a vertical wind profile; a convective heat transfer coefficient calculated from the local wind velocity simulated with a CFD code. For the impact of air temperature on convection, two modalities are considered the use of the temperature measured at the nearest meteorological station; a local temperature calculated with the CFD simulation. For the impact of long-wave radiative exchanges, three modalities: the building exchanges with the sky without taking into account the masks of the environment and the long-wave radiative exchanges with the other surfaces; the building exchanges with the sky, taking into account the mask effects but not the exchanges with the surrounding surfaces; long-wave exchanges are taken into account with all kinds of surfaces in function of view factors. For the impact of short-wave radiations, two modalities: only direct and diffuse solar fluxes are taken into account; inter-reflections are considered. The results indicate that if the calculation of air temperature and convective heat transfer coefficient have few impacts in all the cases, the way of calculating long-wave and short wave radioactive fluxes has to be carefully considered, in winter as in summer. More detailed recommendations are given according to the density of the site in which the building will be implemented.
A lot of geographers, scientists believe that the current climate has changed. Especially, since the rapid increment of world's population. Indeed, rapid urbanization led to an increased demand of basic facilities, such as public transport services, hospitals, housing &, etc. Accordingly; the urban areas of cities have been expanded compared to rural areas, and many modifications and changes have been happened on their surface's materials. These modifications made our cities hotter than the Countryside, UHI effect phenomenon now well-known. One of the main reasons behind these changes is construction materials in both buildings and urban spaces, which play a major role in affecting the urban temperatures, precisely near-surface air temperatures positively or negatively, which depend mainly on the behaviour of the surface with solar radiation and how the energy is reflected, emitted, and absorbed. Thus, the current study aimed to investigate the direct and indirect impacts of materials reflection coefficient on the environmental performance and external urban surface temperature; by using the SOLENE-microclimate model tool (developed by the laboratory CRENAU - ENSA Nantes); which is a direct effect on external air temperature in terms of sustainability in the urban context. This study applied on one of the most important residential complexes in Mosul city - Iraq as a case study. The results were proved that when used a material with high reflectivity; Comparing low albedo Scenario(1) with high albedo Scenario(3); it can improve the thermal behaviour of building and urban surfaces, where the surfaces temperature of rooftop, walls, urban spaces, road have been changed by, respectively, 25°C, 18°C, 20°C, and 18°C. As well as changed the urban air temperature by 11°C. However, the results showed that in some cases the surface temperatures increased slightly even when reflectivity increased in the scene, (comparison scenario 3 and scenario 5) where the change of albedo value of external walls surfaces have affected increasing the average urban spaces & pavement temperature about 2°C. The tool that is used in this study (SOLENE-microclimate) has effectively helped in achieving all the analysis required successfully, which it represent the most specialized tool in this field.
Marjorie Musy
added a research item
Nowadays, the study of the outside thermal comfort is more and more taking into consideration in the urban design process. In a climate change context, town planners have to find solutions to mitigate the effects of the global warming and to ensure that outside spaces designed in new districts will remain liveable.
Marjorie Musy
added 4 research items
The building simulation tools available to evaluate energy consumption are numerous. Nevertheless, the main lack of the majority of these tools is the ability of consider the environment where the studied building is. Moreover, some of them impose strong constraints such as the choice of walls composition limited to several predefined walls or the value of the convection exchange coefficient which can not be modified.
A full coupling between a CFD code, a thermo-radiative model and a building energy simulation model enables Solene-microclimat software to calculate both building thermal behavior and urban microclimate with the retroaction of buildings on microclimate. However, this full coupling is time consuming and it is legitimate to wonder if it is always necessary to perform such detailed simulations. In the framework of the MERUBBI project, simulations were carried out to answer this question. A set of simulations was designed to explore different kinds of configurations: three cities in France (Nantes, Paris and Strasbourg), three levels of density (from an isolated building to an implementation in the dense city center) and three kinds of buildings (an individual house in Paris, a residential building in Nantes and an office building in Strasbourg). To study the sensitivity of energy demand to the coupling detail, for each thermal flux at the external surfaces of the building, several levels of details were taken into account. For the impact of wind on convection, three modalities were considered: a constant convective heat transfer coefficient, calculated from the wind velocity at 10m; a convective heat transfer coefficient calculated from a vertical wind profile; a convective heat transfer coefficient calculated from the local wind velocity simulated with a CFD code. For the impact of air temperature on convection, two modalities are considered the use of the temperature measured at the nearest meteorological station; a local temperature calculated with the CFD simulation. For the impact of long-wave radiative exchanges, three modalities: the building exchanges with the sky without taking into account the masks of the environment and the long-wave radiative exchanges with the other surfaces; the building exchanges with the sky, taking into account the mask effects but not the exchanges with the surrounding surfaces; long-wave exchanges are taken into account with all kinds of surfaces in function of view factors. For the impact of shortwave radiations, two modalities: only direct and diffuse solar fluxes are taken into account; inter-reflections are considered. The results indicate that if the calculation of air temperature and convective heat transfer coefficient have few impacts in all the cases, the way of calculating long-wave and short wave radioactive fluxes has to be carefully considered, in winter as in summer. More detailed recommendations are given according to the density of the site in which the building will be implemented.
A lot of geographers, scientists believe that the current climate has changed. Especially, since the rapid increment of world's population. Indeed, rapid urbanization led to an increased demand of basic facilities, such as public transport services, hospitals, housing &, etc. Accordingly; the urban areas of cities have been expanded compared to rural areas, and many modifications and changes have been happened on their surface's materials. These modifications made our cities hotter than the Countryside, UHI effect phenomenon now well-known. One of the main reasons behind these changes is construction materials in both buildings and urban spaces, which play a major role in affecting the urban temperatures, precisely near-surface air temperatures positively or negatively, which depend mainly on the behaviour of the surface with solar radiation and how the energy is reflected, emitted, and absorbed. Thus, the current study aimed to investigate the direct and indirect impacts of materials reflection coefficient on the environmental performance and external urban surface temperature; by using the SOLENE-microclimate model tool (developed by the laboratory CRENAU-ENSA Nantes); which is a direct effect on external air temperature in terms of sustainability in the urban context. This study applied on one of the most important residential complexes in Mosul city-Iraq as a case study. The results were proved that when used a material with high reflectivity; Comparing low albedo Scenario (1) with high albedo Scenario (3); it can improve the thermal behaviour of building and urban surfaces, where the surfaces temperature of rooftop, walls, urban spaces, road have been changed by, respectively, 25 ºC, 18 ºC, 20 ºC, and 18 ºC. As well as changed the urban air temperature by 11 °C. However, the results showed that in some cases the surface temperatures increased slightly even when reflectivity increased in the scene, (comparison scenario 3 and scenario 5) where the change of albedo value of external walls surfaces have affected increasing the average urban spaces & pavement temperature about 2 °C. The tool that is used in this study (SOLENE-microclimate) has effectively helped in achieving all the analysis required successfully, which it represent the most specialized tool in this field.
Marjorie Musy
added 2 project references
Marjorie Musy
added a project goal
From 2006, I have coordinated the development of the urban microclimate simulation software SOLENE-microclimat.