Yoshihide Tominaga

• PhD
• Professor at Niigata Institute of Technology

This study examines the peak wind speed statistics and their uncertainty at the pedestrian level around an isolated building model using Large-Eddy Simulation (LES). Understanding pedestrian-level wind conditions is crucial for building design focused on comfort and safety. Traditional methods, often limited by the inability to directly assess peak...

The relationship between corrosion damage and salinity concentration transported by the wind flow around a building was investigated using computational fluid dynamics (CFD) applied to a large sports stadium as a case study. First, a CFD-based estimation method for salt deposition resulting from wind flow was developed and applied to a large sports...

Cross-ventilation is inadequate in double-loaded inexpensive flats, especially on the leeward side of the structures, widespread in tropical developing nations. Using validated CFD models, this work attempts to parametrically assess closed-vertical void designs to optimise the ventilation efficiency of a double-loaded apartment building. The aspect...

The accuracy of wind power generation predicted by computational fluid dynamics (CFD) simulations combined with meteorological wind data was validated based on comparisons with directly measured data for a small vertical axis wind turbine system installed on a university campus. The CFD simulations were performed in accordance with established guid...

This paper introduces recent activities related to the structural and environmental engineering in Japan. Part 1 in this paper illustrates outline of recent research and standardization related to ensuring wind resistant performance of tiled roofs. We introduce the results of damage survey on tiled roofs caused by Typhoon Faxai in 2019, which was c...

Structures are known to incur damage from airborne sea salt adhesion; especially, steel structures exposed to open air, such as sports stadiums, in coastal areas are considerably damaged due to airborne sea salt adhesion. In this study, the relationship between the corrosion damage due to salt adhesion and the detailed airflow distribution around a...

This study comprehensively investigated the accuracy of computational fluid dynamics (CFD) simulations for predicting the mean and turbulent wind characteristics around a high-rise building surrounded by low-rise street canyons. The flow field was characterized based on the complicated interaction between a high-rise building and its surrounding bu...

In computational fluid dynamics (CFD) simulations of airflow in built environments, the porous-jump model is commonly used to represent extremely thin porous windbreak fences, which have much smaller sizes than the neighborhood computational cells. However, owing to the limited quantitative validation studies that include turbulence characteristics...

This study reports the results of a post-disaster survey for residential environment in Chiba Prefecture after Typhoon Faxai on Sep. 9, 2019. Besides to damage surveys for houses caused by strong winds, questionnaire surveys on the residential environment, which inquired about the change of the residential environment after the disaster, were condu...

In this paper, a method to evaluate the roof snow load using acceleration measurement is proposed. Its applicability was confirmed by being applied to snow load on a semi-full-scale wooden structure building model. The natural frequency change caused by the roof load variations was investigated by acceleration measurement using an inexpensive instr...

Double-loaded affordable apartments, which are commonly seen in tropical developing countries, suffer from poor cross-ventilation, particularly on the leeward side of the buildings. This study aims to parametrically evaluate closed-vertical void configurations to improve the ventilation performance of the double-loaded apartment building using the...

In this study, wind tunnel experiments were conducted to determine the relationship between the texture of road surfaces and the threshold wind velocity that causes the movement of sparsely distributed gravels. We proposed a method that uses analogous particles having lower densities compared to actual gravel, considering the threshold velocity for...

Plume buoyancy is one of the most crucial driving forces of gas pollutant dispersion in weak wind regions such as the recirculation region. In this study, steady Reynolds-averaged Navier-Stokes (SRANS) simulation and large eddy simulation (LES) are conducted simultaneously to investigate the flow and concentration fields around a cubic building, in...

Airborne transmission is an important route of spread of viral diseases (e.g., COVID-19) inside the confined spaces. In this respect, computational fluid dynamics (CFD) emerged as a reliable and fast tool to understand the complex flow patterns in such spaces. Most of the recent studies, nonetheless, focused on the spatial distribution of airborne...

This paper presents a high tempo-spatial resolution dataset of the three-dimensional (3D) turbulent flow over a group of generic buildings with and without a high-rise building measured in an atmospheric boundary layer wind tunnel. This dataset is the basis of the study reported in the research article entitled “Wind tunnel measurement of three-dim...

The wind velocity and surface pressure of the model of a group of urban blocks made of low-rise buildings with a high-rise building in the center were measured using a wind tunnel. Not only the time-averaged velocity field, but also the turbulent statistics, i.e., the turbulent kinetic energy, normal component of the Reynolds stresses, gust factor...

We designed and exclusively performed a wind tunnel experiment to obtain high-quality and high-resolution measurement results for three components of mean and fluctuating velocities around a 1: 1: 2 isolated building to establish a benchmark case for large-eddy simulation (LES) as a part of the activities of the Architectural Institute of Japan. Su...

In this study, a multi-fidelity shape optimization framework is proposed for the pedestrian-level wind environment (PLWE). In the proposed framework, low-fidelity computational fluid dynamics (CFD) models based on steady Reynolds-averaged Navier–Stokes equations (RANS) models and high-fidelity CFD models based on large-eddy simulation (LES) are eff...

Accurate estimation of roof snow load is important for safely ensuring the structural performance of buildings in snowy regions. Ground snow weight is a basic design factor used to calculate the roof snow load. In a previous model, the ground snow weight was estimated based on daily precipitation and average temperature. However, this model has a l...

Evaluating roof snow load is an important problem for building design in snowy regions. A semi-full-scale building model was developed to obtain validation data for the model for evaluating roof snow load. The building model was placed in an observational field in Nagaoka City, where extensive weather conditions were measured. The seasonal change i...

Cross-ventilation flow in buildings is dominantly impacted by the characteristics of their surrounding built environment, specifically in highly-dense urban areas. Cross-ventilation in highly-dense urban configurations is studied using validated computational fluid dynamics models using the large eddy simulation approach. Mean flow properties, turb...

Double-loaded affordable apartments are commonly seen in tropical developing countries to maximize total floor areas. However, the double-loaded apartments would possibly cause poor cross-ventilation, particularly on the leeward side of the buildings. This study aims to propose an alternative design for double-loaded affordable apartments for effic...

Snow accumulation during winters poses significant challenges to realization of engineering applications, such as operation of infrared detection sensors. This paper presents the utility of coupled computational fluid dynamics (CFD) simulations and discrete phase model (DPM) to predict the occurrence of snow accumulation on infrared detection senso...

In this study, a systematic calibration methodology is proposed for enhancing the accuracy of urban airflow simulations using computational fluid dynamics (CFD) models based on the Reynolds-averaged Navier-Stokes (RANS) equations. In the calibration process, high-quality data from different sources are used to define the validation metrics, which a...

Computational fluid dynamics (CFD) results generated by the steady Reynolds-averaged Navier-Stokes equations (SRANS) model and large eddy simulation (LES) are compared with wind tunnel experiments for investigating a cross-ventilation flow in a group of generic buildings. The mean flow structure and turbulence statistics are compared for SRANS base...

There is an increase in the middle income class in the tropical cities of the global south. Which has lead governments to focus on the provision of sustainable housing stocks. The design of these houses is a concern as they are often designed to maximize occupancy. Based on analysis of existing building design, the standard midrise buildings of Ind...

Appropriate large-eddy simulation (LES) guidelines for pedestrian wind environments are being established by the working group of the Architectural Institute of Japan. We conducted LESs for a flow field around an isolated building to clarify the influence of computational conditions on turbulent statistics. We performed a cross-comparison study by...

This study presents the experimental results on cross-ventilation in a generic low-rise building placed in highly-dense urban configurations. Flow visualization studies were conducted by utilization of a smoke generator in order to investigate the nature of the flow pattern inside and around the cross-ventilated building. Moreover, distribution of...

Computational fluid dynamics (CFD) models based on the steady Reynolds-averaged Navier Stokes (SRANS) equations are vastly used for calculation of airflow field inside and around cross-ventilated buildings. However, most of the developed CFD guidelines neglect CFD challenges related to cross-ventilation modeling in terms of flow unsteadiness, high...

It was found that the standard design of multistory apartments of Indonesia and Mumbai consists of a double loaded corridor to maximize the floor area regardless of the orientation. Consequently, the occupants on the leeward side may encounter poor cross-ventilation. This study aims to determine optimum void design allowing sufficient cross-ventila...

Unbalanced snow accumulation resulting from wind flow represents a difficult problem when predicting snow loads on building roofs. Accumulation occurs because of the complex interaction between snow particle motion and fluid flow, which is affected by building geometry. Recently, computational fluid dynamics (CFD) was applied to the prediction of s...

Large-eddy simulations were performed for the velocity fields around a 1:1:2 single block model to clarify the effect of the numerical viscosity in different advection schemes. Six types of advection schemes with different numerical viscosities were employed: second-order central, first-order upwind, and blending schemes with ratios of 95:5, 90:10,...

A series of computational fluid dynamics simulations was performed using large-eddy simulation (LES) of single-sided natural ventilation for a generic building model, so as to investigate the impact of guide vanes (GVs) and adjacent obstacles on the air change rate and ventilation efficiency. A building model with two openings on one sidewall align...

Results of an extensive wind tunnel experimental measurements for cross-ventilation in a sheltered building are presented against different wind angles. Buildings were placed in a regular arrangement with a constant planar area ratio of 0.25. Instantaneous velocity components were measured inside and around the cross-ventilated building using a spl...

A wind tunnel experiment on sand erosion/deposition around a cube was performed to clarify the basic phenomena and obtain validation data for computational fluid dynamics (CFD) analysis. The experiment was conducted in the atmospheric boundary layer wind tunnel at the Niigata Institute of Technology in Japan. A cubic model with width 200 mm was loc...

This study performs computational fluid dynamics simulations for flow and dispersion fields around an isolated cubic building model with tracer gases being exhausted from an exit behind the building. The tracer gases have three different buoyancies according to the difference in density with ambient air and, therefore, behave as neutral, light, and...

Accurate representation of turbulence phenomenon in Computational Fluid Dynamics (CFD) modeling of cross-ventilation around and inside buildings is a challenging and complex problem, especially under the sheltering effect of surrounding buildings. Steady Reynolds Averaged Navier-Stokes (RANS) models are broadly used in many practical applications....

In this study, we conducted large-eddy simulations (LESs) for a flow field around an isolated building model to clarify the influence of computational conditions on turbulent statistics. Appropriate LES guidelines for a built-up environment are being established by the working group of the Architectural Institute of Japan. We performed a cross comp...

The performance of unsteady Reynolds-Averaged Navier–Stokes equations (URANS) for simulations of flow and dispersion fields around isolated cubical buildings has been examined in this study. URANS results were compared with those obtained from steady-RANS (SRANS) computations and experiments. The comparison determines not only the applicability of...

This paper reviews the current status of computational fluid dynamics (CFD) modeling of snowdrift around buildings and discusses the review findings to give insight into future applications. First, an overview of past achievements in CFD simulations of snowdrift around buildings is provided by reviewing previous research. The history of model devel...

Accurate and reliable computational fluid dynamics (CFD) simulations are essential for the assessment of cross-ventilation of buildings. To determine which CFD models are most suitable, validation studies are required. A detailed review of the literature indicates that most CFD validation studies only employed the 3D steady Reynolds-averaged Navier...

This paper presents a detailed experimental analysis of flow and dispersion by cross-ventilation in five generic isolated single-zone buildings with different opening positions. First, flow visualization is performed illustrating the highly transient flow and dispersion process dominated by a flapping jet with pronounced Kelvin–Helmholtz instabilit...

In the prediction of roof snow loads on buildings, unbalanced snow distribution due to wind flow on roofs is a problem. Although some experimental research has been carried out using wind and water tunnels, till date, only a few attempts have been made to apply computational fluid dynamics (CFD) to this issue. In this study, a method based on CFD w...

INTRODUCTION Natural cross-ventilation is a complex phenomenon, influenced by the distribution of wind velocity, direction, and total pressure on walls. In recent studies using computational fluid dynamics (CFD), steady-state flow fields in a cross-ventilated house model have been studied. Cross-ventilation is not observed using steady-state simula...

Recently, applications of CFD (Computational Fluid Dynamics) are expanding to various environmental issues such as pollutant/thermal dispersion in urban areas. The outdoor environment sub-committee of the Architectural Institute of Japan have conducted several benchmark tests for obtaining basic information and knowledge in order to provide the ext...

Outdoor air pollution is a major current environmental problem. The precise prediction of pollutant concentration distributions in the built environment is necessary for building design and urban environmental assessment. Near-field pollutant dispersion, involving the interaction of a plume and the flow field perturbed by building obstacles, is an...

This is the review of CFD (Computational Fluid Dynamics) guidelines for dispersion modeling in the USA, Japan and Germany. Most parts of this review are based on the short report of the special meeting on CFD Guidelines held at the International Symposium on Computational Wind Engineering (CWE2014), University of Hamburg, June 2014. The objective o...

This is the review of CFD guidelines for dispersion modeling in US, Japan and Germany. Most parts of this review are based on the short report of the special meeting on CFD Guidelines held at the International Symposium on Computational Wind Engineering (CWE2014), Hamburg University, June 2014. The objective of this meeting was to introduce and dis...

Natural cross ventilation in house is commonly used as ventilation method in Japan. It is influenced by wind direction, distribution of wind velocity and total pressure on walls. Cross ventilation is not observed with using Reynolds Averaged Navier-Stokes Simulation (RANS), nevertheless occurs in actual phenomena. Flow field in the house varies dep...

This study aims to develop a new k-ε model that incorporates the effects of snow particles on a flow field. In the first part of this paper, the results of wind-tunnel measurements of a flow over a loose-snow surface are presented. The spatial distributions of the mass flux of drifting snow, wind velocity, and turbulence were simultaneously measure...

In this study, the performance of the unsteady Reynolds-averaged Navier–Stokes (URANS) turbulence modeling of the flow field around a high-rise building with a 1:1:2 shape was examined. The unsteady fluctuation behind the building was successfully reproduced by URANS computation using the k–ω shear stress transport (SST) model. This reproduction co...

Recently, computational fluid dynamics (CFD) has been widely used for the prediction and analysis of cross-ventilation flows in buildings. In this study, detailed wind tunnel experiments were performed on the cross-ventilation flow of a generic single-zone building in order to compile a validation database for CFD methods. Both the velocity fields...

Cross ventilation in interior spaces is a commonly adopted means of providing natural ventilation in Japan during moderate seasons, including summer. Cross ventilation is occurred by interaction that caused by the airflow in interior and exterior rooms and the pressure distribution of the building walls. The airflow distribution varied depending on...

Computational fluid dynamics (CFD) simulations of the evaporative cooling effect from water surfaces in a micro-scale urban environment were evaluated via validation and application studies with various configurations. First, the basic ability of CFD simulations to reproduce the evaporative cooling on a simplified small-scale water surface in a bou...

A criterion for pedestrian wind environment based on probability of exceedance of daily maximum gust wind speed is commonly used in Japan. We usually use gust factors to estimate the daily maximum gust wind speeds, using daily maximum mean wind speeds. But there still remains an unsettled problem of how to determine the appropriate gust factors. “A...

Near-field pollutant dispersion in the urban environment involves the interaction of a plume and the flow field perturbed by building obstacles. In the past two decades, micro-scale Computational Fluid Dynamics (CFD) simulation of pollutant dispersion around buildings and in urban areas has been widely used, sometimes in lieu of wind tunnel testing...

In order to apply Computational Fluid Dynamics (CFD) techniques to estimate pollutant dispersion in urban areas, it is important to assess the performance of numerical models used to estimate these phenomena. Recently, the MUST (Mock Urban Setting Test) has often been adopted as a test case for evaluating numerical models for micro-scale urban mete...

This study aims to develop a new drifting snow model that solves two transport equations of drifting snow densities of the snow particles falling from the sky and those coming from the ground surface. Because the shape of snow particles falling from the sky is completely different from that of snow particles lifted up from the snow surface which ar...

In this study, a CFD (computational fluid dynamics) technique is used to investigate the roles of urban geometry, wind direction, and wind velocity in an urban environment. By applying efficiency concepts originally developed for indoor environments, the term “ventilation” is used as a measure of city “breathability.” Two types of building geometri...

Graphical Abstract

Wind tunnel measurements over loose snow surface were carried out to experimentally investigate the characteristics of drifting snow phenomena in a non-equilibrium boundary layer and to obtain data for examining the numerical model of snow transport coupled with the computational fluid dynamics (CFD). In this experiment, the spatial distributions o...

Modeling of turbulent scalar flux in CFD (Computational Fluid Dynamics) for near-field dispersion around buildings is examined by investigating both velocity and concentration fields obtained by two modeling approaches, i.e., RANS RNG k-ε and LES. A building array model with a point source located in between the central buildings is adopted as a ta...