Due to the increase in temperature because of global warming, cities that are more densely populated experience higher temperatures compared to surrounding rural areas, which are more noticeable at night.
Urban areas can experience surface temperatures that are approximately 10.83% higher than those in rural areas.
This phenomenon is known as the urban heat island effect, and it can be tackled by using computational fluid dynamics (CFD) simulations. This effect is caused by the use of thermally massive building materials, urban surfaces with low albedo, complex urban morphology, and waste heat.
This article will explore the methodologies and applications of CFD in heat mitigation to address the urban heat island effect.
A study by Toparlar et al. revealed the use of CFD in heat mitigation analysis for urban microclimate modeling. It was highlighted that complex urban geometry and its impact on airflow patterns and temperature distribution could help in mitigating the heat effect.
The study revealed how simulation findings were sensitive to urban geometry, which reflected the requirements for pedestrian wind comfort and thermal comfort in urban settings.
Some other examples are as follows:
CFD in heat mitigation is useful in understanding how air moves through narrow street canyons, especially in cities like New York, with tall buildings in the skyline. The locations of hot spots and ventilation corridors can be found with the aid of wind pattern simulations.
In a study conducted in Vienna, researchers used CFD in heat mitigation to model how building heights and orientations affect wind flow, identifying areas where airflow could be increased through strategic urban planning. CFD in heat mitigation can assess how different materials and surface types (e.g., asphalt vs. green roofs) influence local climates.
The ENVI-met simulation tool, widely used for microclimate modeling, has been shown to effectively simulate interactions between buildings, vegetation, and atmospheric conditions.
In a study conducted in Padua, Italy, researchers implemented ENVI-met to evaluate the impact of different mitigation strategies, such as increasing tree canopy cover and using reflective building materials. The simulations gave quantitative data on temperature reductions, thereby improving thermal comfort for pedestrians and demonstrating the effectiveness of targeted interventions.
Here are some of the urban heat island mitigation strategies, focusing on green solutions and their impact on energy savings and temperature reduction.
Impact on Temperature and Energy Savings: CFD models can simulate the airflow patterns around tree canopies. This allows the best results for the analysis of their cooling effects on nearby surfaces and air temperatures.
For example, CFD in heat mitigation studies in cities like Atlanta have shown that strategically placed trees can lower air temperatures by an average of 2.57°C within 10 meters of their canopy.
Energy Savings: CFD models can predict different tree placements and densities, and urban planners can estimate tree canopy coverage to maximize cooling benefits.
A study conducted in New York City estimated that increasing tree cover by 10% could reduce energy demand for cooling by approximately 2-3%. This will bring down energy costs and lessen the strain on the electrical grid during peak summer months.
Cooling Effects: Green roofs contribute to urban cooling by absorbing sunlight and reducing heat absorption compared to traditional roofing materials. CFD simulations can assess how green roofs affect the thermal performance of buildings and their surrounding environments.
Energy Efficiency: CFD can also evaluate the impact of green roofs on energy consumption for heating and cooling.
In Chicago, CFD simulations demonstrated that buildings with green roofs experienced a 25% reduction in energy use for air conditioning during summer months. This highlights the potential for green roofs to enhance energy efficiency in densely populated urban areas.
Temperature Reduction: Cool pavements are designed to reflect more sunlight and absorb less heat than conventional pavements. CFD can model the thermal performance of different pavement materials, allowing cities to identify the most effective solutions for reducing surface temperatures.
For example, a trial in Sydney indicated that lighter pavements could reduce surface temperatures compared to traditional dark asphalt.
At Mechartes, our team is comprised of highly qualified engineers with domain expertise in mechanical and software engineering. As one of the best CFD Analysis Services Consultancy Companies, we pride ourselves on accurate simulation results and CFD consulting.
Professionalism: We approach every project with a professional mindset, with rigorous analysis and reliable outcomes.
Advanced Methods: With sophisticated, unique, cutting-edge methods, simulation algorithms, and computing power, we deliver results that delight our clients.
Experience: With over 16 years of experience, we’ve honed our skills in Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA).
Urban Heat Island Mitigation: We’re passionate about leveraging CFD to combat the urban heat island effect in metro cities. Our simulations guide sustainable practices, from green roofs to reflective pavements.
Building & Construction: We optimize HVAC design for thermal comfort, ensuring ideal air temperature, velocity, and humidity.
Oil, Gas & Power: Our expertise extends to API standards compliance, tank design, and flow-induced vibration studies.
Data Centers: We’ve cracked the code for future-proof data centers, addressing ventilation challenges.
Here’s a case study conducted by Mechartes on outdoor thermal comfort using CFD. This study aimed to enhance the comfort of occupants in a large souk street corridor and open area in the Middle East.
Let’s go over the key aspects:
The primary objective was to provide a comfortable environment for visitors in the souk during peak summer evenings.
Specifically, the focus was on exploring ventilation strategies to optimize comfort.
The client initially considered High-Volume, Low-Speed (HVLS) fan systems to enhance air circulation.
Our research revealed that fan placement had minimal impact on air movement, as velocities remained high across all fan locations.
We shifted our focus to the HVAC system specifically designed for the souk.
CFD simulations were employed to evaluate different ventilation and cooling options.
Parameters such as air velocity, dry bulb temperature, and relative humidity were considered.
The UTCI, representing perceived temperature, guided our analysis.
We assessed how different design choices influenced thermal comfort.
Optimal ventilation strategies were identified.
The study informed design decisions, ensuring a comfortable environment for souk visitors during warm evenings.
To learn more about this case study, click here.
Increasing the use of CFD for the urban heat island effect in metro cities offers promising solutions for enhancing urban microclimates. CFD simulations provide critical insights into airflow, temperature distribution, and the impacts of urban geometry and green solutions like trees and green roofs.
Multiple studies have also demonstrated significant temperature reductions and energy savings through strategic planning and design changes informed by CFD.
Join us at Mechartes for a detailed exploration of CFD applications in urban heat mitigation.
Contact Us today!
Share 
Facebook 
Youtube 
linkedin 
Twitter