Wind Flow Field Research Articles

Wind leading to improve cooling performance of natural draft air-cooled condenser

Natural draft air-cooled condenser (NDACC) has been adopted in chemical and power plants owing to its superior energy-efficient operation to the traditional fan-driven air-cooled condenser. However, the cooling capability of NDACC is generally impaired by ambient winds, which incur the unbalanced airflow distributions through the condenser cells. So, the wind flow fields are organized in this research to restrain the adverse wind effects. By numerical simulations, five types of windbreakers are studied and compared with the no-windbreaker case. The air velocity, pressure and temperature distributions, and the specific air flow rates of condenser cells as well as heat rejections of cooling sectors are analyzed. Furthermore, the three-dimensional path lines are additionally presented to highlight the leading effects of windbreakers, airflow inside the tower, and flow discharge at the tower outlet. The results show that, appropriate windbreaker configurations can effectively improve the cooling performance of NDACC, especially at high wind speeds, while the windbreaker arrangement inside the condenser cells plays a negligible role in the overall cooling performance. Besides, the cases with 12 and 48 exterior windbreak walls achieve almost the same best performances. In consideration of the system robustness and economy, the case with 48 exterior windbreakers can be recommended in the future engineering application.

Rain sheltering analysis in semi-outdoor environments: case study on passenger comfort in a railway station shelter

Wind-flow field around a semi-outdoor structure can differ significantly from the one around a building. As a result, the design of such a structure can have a strong impact on the rain exposure. This paper studies the wind-driven rain (WDR) sheltering for a prototype of a small railway station shelter designed for rural areas. Computational fluid dynamics simulations of WDR are performed based on an Eulerian multiphase model. A new metric called “wetting ratio” is proposed, which allows for quantitative analysis of wetting due to rain within a volume in the air. The rain exposure of standing passengers is discussed for a range of meteorological conditions based on yearly climate data. The analyses indicate the critical meteorological conditions and orientations that lead to the highest rain exposure. It is found that minor geometrical modifications, such as side window length, can have a significant impact on the rain exposure.

Model study on the influence of plant design, photochemistry and meteorology on atmospheric concentrations of nitrosamines and nitramines in vicinity of an amine-based CO2 capture facility

Post combustion using amine solvents is the most mature technology for the capture of CO2 from coal-fired power plants. Yet, amines atmospheric fate and their environmental and human health impacts, after their release by evaporation and solvent degradation from post combustion CO2 capture (PCCC) plants to the surrounding air, remains a key area to address in view of the worldwide installation of large-scale carbon capture and storage facilities. It is therefore crucial to test potential industrial applications with respect to plant design parameters influencing the fate of the amine degradation products. In this work, a method is developed to propose ideal PCCC plant parameters with respect to its design and operation. A risk limiting scenario was modelled on the UK’s largest CO2 capture pilot plant (CCPilot100+) in Ferrybridge using the air dispersion model ADMS, such that the total nitrosamines and nitramines from the amines realised did not exceed the reported atmospheric safety limits of 0.3ng/m3 with respect to human health in the local environment. A parametric sensitivity study was performed to determine the plant design parameters that most influenced the fate of the nitrosamines and nitramines. It was found that stack height and diameter, exit flue gas temperature and velocity are parameters of the PCCC plant can influence the total sum of nitrosamine (NS) and nitramine (NA) from +58% to −42% compared to the baseline parameterization. Environmental parameters, such as the site specific background meteorology and the background photochemistry were also inspected. Meteorology, i.e. mainly wind speed and wind flow field, affected the total NS and NA baseline concentrations from +28% to −10%, and background photochemistry from +165% −65%. In conclusion, if a PCCC plant is constructed with advantageous exhaust geometry, environmentally optimised operation conditions, and placed in an area with low background pollution, the risk associated with employing amines for capturing CO2 emissions might be reduced to a minimum.

Investigation on wind tunnel tests of the Kilometer skyscraper

Wind tunnel tests were carried out to investigate the wind pressure distribution of a super high-rise building with a height of 1040m in China. The huge model size led to several technical difficulties, including simulation of large scale wind flow fields, correction of distortion effects caused by tubing systems and synchronization correction for data in batches. To simulate the wind field with an elevation of one kilometer above the ground, custom designed grid and roughness elements were adopted as flow-adjustment passive devices. According to the matrix transfer method, a set of transfer functions for tubing systems with different lengths were established to eliminate the effect of distortion on fluctuating pressure measurement. A correction method based on Generalized Regression Neural Network (GRNN) was proposed to get time-synchronized data of the whole building. After solving these problems, the mean and extreme pressure coefficients were studied for the distribution of wind-induced pressure. For this model with triaxial symmetry, the distribution of wind pressure shows good symmetry. With the increase of height, largest peak positive wind pressure coefficients increase, while smallest peak negative wind pressure coefficients decrease. The solutions to technical problems and the outcome of wind pressure distribution are expected to be useful to engineers and researchers involved in this field.

The development and testing of a novel external-spraying injection dedusting device for the heading machine in a fully-mechanized excavation face

Abstract This paper discusses the development of a novel external-spraying injection dedusting device, which has the potential to reduce substantially the amount of dust produced by a heading machine during the cutting process in a fully-mechanized coal face. Firstly, the migration rules of the inner wind flow field are analyzed using numerical simulations, and then the atomization function of the spraying nozzle is optimized. Consequently, the nozzle exhibited the highest airborne dust reduction rate at a spraying pressure of 4 MPa. The proposed device’s functionality was also tested by experiments, with the results indicating that as the spraying pressure increased from 2 MPa to 8 MPa, the gas–liquid ratio increased at first and then decreased, reaching a maximum of 1.269 at a spraying pressure of 4 MPa, which was subsequently once again selected as the optimal spraying pressure. Finally, field experiments were conducted on the developed dedusting device, with the results showing that, compared with the original spraying dust reduction method, when the developed external-spraying injection dedusting device was opened, using the dust reduction method (d), the average dust reduction rates of the total coal and respirable dust are enhanced by 17.0% and 18.3% respectively; moreover, using the dust reduction method (c), the average dust reduction rates of total coal and respirable dust are enhanced by 11.6% and 12.0% respectively. Therefore, it can be calculated that by using the injection dedusting method, the average reduction rates are enhanced by 5.4% and 6.3% respectively. In particular, the use of one of the proposed dust removal methods at the measuring point where the machine’s driver is located, led to the average concentrations of total dust and respirable dust decreasing from 305.1 mg/m 3 and 129.5 mg/m 3 to 88.2 mg/m 3 and 38.3 mg/m 3 respectively.

Aerodynamic performance analysis of wind-sand flow on riding-type hangers of suspension bridges

With global climate and environment deterioration, the desertification is getting worse and the phenomenon of wind-sand flow frequently occurs in many areas. Hangers of suspension bridges may suffer the impact from wind-sand flow and be damaged. In this study, the riding-type hangers with four strands which are the commonly used hanger of long-span suspension bridges are taken as an example to investigate the influence of wind-sand flow on the hangers. The aerodynamic interference effect can occur among the four strands under the action of wind-sand flow. In order to explore the influence of wind-sand flow on the hangers, the wind-sand flow field around the riding-type hangers of a long-span suspension bridge is simulated within the FLUENT software on the basis of the numerical simulation of computational fluid dynamics. The pressure and velocity contour, aerostatic coefficients and forces produced by the wind-sand flow under different wind attack angle and volume fractions of sand phase are analyzed from the simulation. Results indicate that the forces exerted by the wind-sand flow on riding-type hangers are greater than the forces exerted only by wind. In the wind and wind-sand flow field, the drag and lift coefficients of the front two strands of hangers exhibit minor changes with increasing wind attack angle, whereas those of the back two strands increase first and then decrease to a small value. The volume fraction of the sand phase has an insignificant effect on the drag and lift coefficients, but has a significant effect on the force exerted on the hanger, and the force exerted on the hangers multiplies when the volume fraction of the sand phase multiplies. The results lay a theoretical foundation for the corrosion fatigue analysis of riding-type hangers for large-span suspension bridges under the action of wind-sand flow.

Simulation of gaseous pollutant dispersion around an isolated building using the k–ω SST (shear stress transport) turbulence model

ABSTRACTThe dispersion of gaseous pollutant around buildings is complex due to complex turbulence features such as flow detachment and zones of high shear. Computational fluid dynamics (CFD) models are one of the most promising tools to describe the pollutant distribution in the near field of buildings. Reynolds-averaged Navier-Stokes (RANS) models are the most commonly used CFD techniques to address turbulence transport of the pollutant. This research work studies the use of closure model for the gas dispersion around a building by fully resolving the viscous sublayer for the first time. The performance of standard model is also included for comparison, along with results of an extensively validated Gaussian dispersion model, the U.S. Environmental Protection Agency (EPA) AERMOD (American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model). This study’s CFD models apply the standard and the turbulence models to obtain wind flow field. A passive concentration transport equation is then calculated based on the resolved flow field to simulate the distribution of pollutant concentrations. The resultant simulation of both wind flow and concentration fields are validated rigorously by extensive data using multiple validation metrics. The wind flow field can be acceptably modeled by the model. However, the model fails to simulate the gas dispersion. The model outperforms in both flow and dispersion simulations, with higher hit rates for dimensionless velocity components and higher “factor of 2” of observations (FAC2) for normalized concentration. All these validation metrics of model pass the quality assurance criteria recommended by The Association of German Engineers (Verein Deutscher Ingenieure, VDI) guideline. Furthermore, these metrics are better than or the same as those in the literature. Comparison between the performances of and AERMOD shows that the CFD simulation is superior to Gaussian-type model for pollutant dispersion in the near wake of obstacles. AERMOD can perform as a screening tool for near-field gas dispersion due to its expeditious calculation and the ability to handle complicated cases. The utilization of to simulate gaseous pollutant dispersion around an isolated building is appropriate and is expected to be suitable for complex urban environment.Implications: Multiple validation metrics of turbulence model in CFD quantitatively indicated that this turbulence model was appropriate for the simulation of gas dispersion around buildings. CFD is, therefore, an attractive alternative to wind tunnel for modeling gas dispersion in urban environment due to its excellent performance, and lower cost.

Evaluation of single and multiple Doppler lidar techniques to measure complex flow during the XPIA field campaign

Abstract. Accurate three-dimensional information of wind flow fields can be an important tool in not only visualizing complex flow but also understanding the underlying physical processes and improving flow modeling. However, a thorough analysis of the measurement uncertainties is required to properly interpret results. The XPIA (eXperimental Planetary boundary layer Instrumentation Assessment) field campaign conducted at the Boulder Atmospheric Observatory (BAO) in Erie, CO, from 2 March to 31 May 2015 brought together a large suite of in situ and remote sensing measurement platforms to evaluate complex flow measurement strategies. In this paper, measurement uncertainties for different single and multi-Doppler strategies using simple scan geometries (conical, vertical plane and staring) are investigated. The tradeoffs (such as time–space resolution vs. spatial coverage) among the different measurement techniques are evaluated using co-located measurements made near the BAO tower. Sensitivity of the single-/multi-Doppler measurement uncertainties to averaging period are investigated using the sonic anemometers installed on the BAO tower as the standard reference. Finally, the radiometer measurements are used to partition the measurement periods as a function of atmospheric stability to determine their effect on measurement uncertainty. It was found that with an increase in spatial coverage and measurement complexity, the uncertainty in the wind measurement also increased. For multi-Doppler techniques, the increase in uncertainty for temporally uncoordinated measurements is possibly due to requiring additional assumptions of stationarity along with horizontal homogeneity and less representative line-of-sight velocity statistics. It was also found that wind speed measurement uncertainty was lower during stable conditions compared to unstable conditions.

Pedestrian Level Turbulent Wind Flow around an Elevated Building

Wind flow turbulence plays a critical role in the pedestrian level wind environment, particularly for the airflow around buildings with specific architectural features. The elevated design, a feature was proved to improve the pedestrian level weak wind conditions in high-density cities in our earlier study. This present study aims to further investigate the pedestrian level wind flow turbulence in an elevated building surrounding. The predictions were conducted by comparing the CFD simulation and a wind tunnel experiment. Specifically, the Detached Eddy Simulation (DES), the Steady-state and the Unsteady-state RANS (SRANS and URANS), were assessed. The effects of mesh resolutions and inflow fluctuating algorithms on the performance of the DES model were thoroughly evaluated. DES can better reproduce the mean flow fields than the other two models. The unsteady flow fluctuations around the elevated building are analyzed with energy spectral density. Meanwhile, the periodical wind flow fields around the elevated building are accurately obtained.

Analysis of time-resolved wind-driven rain on an array of low-rise cubic buildings using large eddy simulation and an Eulerian multiphase model

Time-resolved wind-driven rain (WDR) load is investigated on an array of low-rise cubic buildings using an Eulerian multiphase (EM) model together with large eddy simulation (LES). The influence of wind-flow unsteadiness on the unsteady behavior of raindrops and the WDR intensity is discussed in detail. The wind-flow field predicted with LES has been validated with wind-tunnel measurements. The mean WDR intensity values obtained using the EM model are found to be in agreement with in-situ WDR measurements. The time-resolved simulations show that the instantaneous specific catch ratio values of smaller droplets fluctuate a lot around their mean values due to higher influence of turbulence. Instantaneous specific catch ratios for the smallest raindrops are mainly dictated by local turbulent structures present in the shear layer or below the rooftop level. On the other hand, the motion of larger raindrops is mainly influenced by the larger-scale motions above the cubes. It is also shown that, running means of the specific catch ratio over a time window of 100–300 s of physical time stabilize to a constant value.

Numerical investigation of dust pollution on a solar photovoltaic (PV) system mounted on an isolated building

Dust deposition on a solar photovoltaic (PV) system mounted on the windward roof of an isolated building was investigated by CFD simulation. The SST k-ω turbulence model with UDF inlet profiles and the discrete particle model (DPM) were adopted to simulate the wind flow fields and the dust deposition behavior, respectively. The CFD wind flow velocity profiles around the building were in good agreement with experimental results reported in the literature. The effects of various dust particle sizes, differing quantities of released dust particles, and the force of gravity on the rates of dust deposition upon the PV panels were investigated in detail. It was found that the dust deposition rate first rose and then declined with the increase of dust particle size. The maximum deposition rate was about 0.28% for 10μm dust, and the minimum deposition rate was about 0.13% for 50μm dust. Gravity also had a significant effect on the rate of dust deposition for large-particle dust (dp>5μm), and the rate could reach 75% for 50μm dust. However, the effect of gravity on dust deposition was less than 5% for small-particle dust (dp<5μm). The effect of releasing differing quantities of dust particles on the dust deposition rate was less than 8%. Moreover, the mechanisms by which dust was deposited on the PV roof were analyzed and discussed. Finally, a simple empirical model was developed to estimate the PV efficiency reduction ratios in relation to exposure time, as based on this study’s CFD results and the experimental data reported in the literature.

CFD analysis of convective heat transfer from ground mounted solar panels

The present study deals with the wind induced convective heat transfer from a ground mounted stand-alone solar panel using Reynolds-Averaged Navier–Stokes (RANS) simulation with Shear Stress Transport (SST) k–ω turbulence model. An unsteady solver with a steady inlet condition is employed. The numerical modeling approach is validated for wind flow field around the solar panel with a Particle Image Velocimetry (PIV) experiment performed in the boundary layer wind tunnel. The solar panel is subjected to two different wind directions (0° and 180°), and for each wind direction, three different incoming flows (wind speeds of 1, 5 and 10m/s at 10m height) are considered. The Convective Heat Transfer Coefficient (CHTC) distributions on the surfaces of the solar panel are analyzed with respect to the flow field around the solar panel. Similar CHTC distribution is observed on both windward and leeward surfaces of the solar panel where natural convection is dominant over forced convection. In contrast, where forced convection is dominant, higher CHTC values (up-to 128%) are found on the windward surfaces compared to the leeward surfaces of the panel. Relation between the dimensionless CHTC parameter Nusselt number (Nu) and the Reynolds number (Re) are presented and the results are compared with previous existing correlations. The lowest Re case (1.0×105), which produces the maximum panel surface temperature and thus will result in minimum electrical efficiency of the panel, is identified to be the most critical case in this study.

A numerical approach to the investigation of wind loading on an array of ground mounted solar photovoltaic (PV) panels

Aerodynamic loads on, and wind flow field around, an array of ground mounted solar photovoltaic (PV) panels, immersed in the atmospheric boundary layer (ABL) for open country exposure, are investigated using the unsteady Reynolds-Averaged Navier–Stokes (RANS) approach. A full scale three-dimensional (3D) solver from OpenFOAM® (ESI Group) is employed with the Shear Stress Transport (SST) k–ω turbulence closure. Several azimuthal wind directions (South, 0°; Southwest, 45°; Northwest, 135° and North, 180°), for a Reynolds number of 3×106, are considered. The numerical modeling approach is validated by comparing the velocity field surrounding a ground mounted stand-alone solar panel with wind tunnel experiments. Detail analysis of wind loading on the array is provided in relation to the wind flow field surrounding the array. The results for the array configuration show that all the trailing rows are in the complete wake of the leading row for straight winds (0° and 180°), but not for oblique winds (45° and 135°). For all four wind directions studied here, the first windward row experiences the maximum wind loads in terms of drag and lift. In terms of the maximum overturning moment, the 45° and 135° wind directions are critical with similar overturning moment coefficients for each row.

Volumetric Three-Dimensional Wind Measurement Using a Single Mobile-Based LiDAR

A novel approach to measure the wind flow field in a utility-scale wind farm is described. The measurement technique uses a mobile, three-dimensional scanning LiDAR system to make successive measurements of the line-of-sight (LOS) wind speed from three different positions; from these measurements, the time-averaged three-dimensional wind velocity vectors are reconstructed. The scanning LiDAR system is installed in a custom-built vehicle in order to enable measurements of the three-dimensional wind flow field over a footprint that is larger than with a stationary scanning LiDAR system. At a given location, multiple series of plan position indicator (PPI) and velocity azimuthal display scans are made to average out turbulent fluctuations; this series is repeated at different locations across the wind farm. The limited duration of the total measurement time period yields measurements of the three-dimensional wind flow field that are unaffected by diurnal events. The approach of this novel measurement technique is first validated by comparisons to a meteorological mast and SODAR at a meteorological observatory. Then, the measurement technique is used to characterize the wake flows in two utility-scale wind farms: one in complex terrain and the other in flat terrain. The three-dimensional characteristics of the wakes are described in the measurements, and it is observed that in complex terrain the wake has a shorter downstream extent than in flat terrain. A maximum deficit in the wind speed of 20–25% is observed in the wake. The location of the maximum deficit migrates upward as the wake evolves; this upward migration is associated with an upward pitching of the wake flow. A comparison of the measurements to a semi-empirical wake model illustrates how the measurements, at full-scale Reynolds numbers, can support further development of wake models.

Wind tunnel and full-scale study of wind effects on a super-tall building

This paper presents the analyzed results from a combined wind tunnel and full-scale study of the wind effects on a super-tall building with a height of 420m in Hong Kong. In wind tunnel tests, mean and fluctuating forces and pressures on the building models for the cases of an isolated building and the building with the existing surrounding condition are measured by the high-frequency force balance technique and synchronous multi-pressure sensing system under two typical boundary layer wind flow fields. Global and local wind force coefficients and structural responses are presented and discussed. A detailed study is conducted to investigate the influences of incident wind direction, upstream terrain conditions and interferences from the surroundings on the wind loads and responses of the high-rise structure. On the other hand, full-scale measurements of the wind effects on the super-tall building have been performed under typhoon conditions. The field data, such as wind speed, wind direction, structural acceleration and displacement responses have been simultaneously and continuously recorded during the passage of 12 typhoons since 2008. Analysis of the field measured data is carried out to investigate the typhoon effects on the super-tall building. Finally, the model test results are compared with the full-scale measurements for verification of the wind tunnel test techniques. The comparative study shows that the wind tunnel testing can provide reasonable predictions of the structural resonant responses. The resonant displacement responses are comparable to the background displacement responses so that the contribution of the background responses to the total displacement responses should not be underestimated. The outcome of the combined wind tunnel and full-scale study is expected to be useful to engineers and researchers involved in the wind-resistant design of super-tall buildings.

Development of a Wind Power System on Trucks

Nowadays, the shortage of fossil fuels consuming on vehicles are in an emergent situation. Moreover, the CO2 emissions from transportations make a very negative impact on our environment. Therefore, to develop a renewable energy system for transportations becomes an important issue and draw a lot of attentions from academia and government agency. The aim of this study is to develop a wind power system for vehicles. A novel win turbine blade was designed and developed based on the methods of literature survey, TRIZ theory, and the theory of aerodynamics. Then, the system integration with gear, generator, and charge controller were carried out on a moving vehicle which could convert the wind power into electrical energy for use and storage. This study uses the CFD simulation software of ANSYS CFX to analyze the wind flow field of a truck, and simulate the dynamic status of the wind turbine in different locations. The result shows that the proposed wind power system on vehicles could generate about 300Watts while the vehicles are moving. The simulation result also provides very good evidence that the most appropriate installation position is in the front roof of a truck, where it could generate better efficiency of electricity in this research.

아라미드섬유 보강 풍력발전기 로터 블레이드의 연성해석 강도평가

Abstract: Because of the energy resources shortage and global pollution, the wind power systems have been developed consistently. Among the components of the wind power system, the rotor blades are the most important component. Generally it is made of GFRP material. Recently, GFRP material has been replaced by CFRP composite material in the blade which has an aerodynamic profile and twisted tip. However the failures has occurred in the trailing edge of the blade by the severe wind loading. Thus, tougher material than CFRP material is needed as like the aramid fiber. In this study, we investigated the mechanical behaviors of the blade using aramid fiber composites about wind speed variation. One-way FSI (fluid-structure interaction)analysis for the wind rotor blade was conducted. The structural analyses using the surface pressure loading resulted from wind flow field analysis were carried out. The results and analysis procedure in this paper can be utilized for the best strength design of the blade with aramid fiber composites.

드릴십 형상에 따른 풍하중 및 유동장 변화

Wind load and flow field of a drillship with respect to various super structures were experimentally investigated in KARI 1m-wide wind tunnel with an atmospheric boundary layer simulation. Six-component external balance and Particle image velocimetry technique were used to measure wind load and velocity vectors in the flow-field around the model respectively. The experimental model was an imaginary shaped drillship with an approximated model which has 1/640 scale compared with recent typical drillships. The test Reynolds number based on the overall length was about 1.5&#xD7;10⁶. It was found that dominant factors influencing on ship wind load are cabin shape and cabin height. Round cabin has smaller axial wind load and narrow boundary layer around the ship than rectangular one, but its yawing moment at certain angles becomes higher. Low cabin height also show positive effects on axial wind load too. Hull shape and forecastle shape show relatively small influences on wind loads except for slight changes around &#xB1;45&#xB0; wind directions.

Investigating the impact on modeled ozone concentrations using meteorological fields from WRF with an updated four–dimensional data assimilation approach

The four–dimensional data assimilation (FDDA) technique in the Weather Research and Forecasting (WRF) meteorological model has recently undergone an important update from the original version. Previous evaluation results have demonstrated that the updated FDDA approach in WRF provides more accurate wind fields aloft than the original approach, particularly during the nocturnal period when low level jets are a common feature in the Eastern United States. Due to the importance of WRF/FDDA meteorological fields in retrospective air quality applications, a modeling study with the Community Multiscale Air Quality (CMAQ) model was undertaken to ascertain if the improved wind flow fields translate into better performance for ozone. To undertake this objective, separate CMAQ model simulations were performed with meteorological inputs generated by WRF using the original and the updated FDDA approaches for a three month summer period. The evaluation effort focused on observed and modeled surface ozone from a mid–morning hour (10 local daylight time (LDT)). Comparisons of modeled results against concentrations aloft from an instrumented tall tower and from available morning vertical profile measurements were also examined. Surface concentrations near 10 LDT are desirable for evaluating the transport process since they are often representative of ozone that has been transported aloft overnight and has undergone downward entrainment in response to convective mixing the following morning. Statistical results from surface observed and modeled concentration pairs indicated modeled ozone from the CMAQ simulation using the updated FDDA meteorology displayed smaller biases and lower absolute errors at 88% and 80% of monitoring sites, respectively, in the Eastern United States. The CMAQ results with the updated FDDA generally exhibited smaller biases and lower absolute errors at monitoring sites across the northern states than in the southeastern states. The results provide evidence that the more accurate wind flows generated with the updated WRF/FDDA approach improved CMAQ model performance based on the statistical results from 10 LDT ozone concentrations.

Numerical Validation for Wind Flow Field in a Street Canyon under Unstable Atmospheric Condition

This paper reports on the validation study of a commercial computational fluid dynamics program, ANSYS FLUENT v14. The purpose of the study was to determine the best turbulent model that can reproduce appropriately the wind flow field of turbulent flow in street canyon under different thermal atmospheric condition. Standard k-ε (SKE) and Large Eddy Simulation (LES) techniques were chosen as the turbulent model for the validation study. It was found that LES could well calculate a complex simulation involving isothermal flow and thermal flow with different thermal intensity and different heat location in street canyon.