• New & Renewable Energy
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• v.9 no.4
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• pp.13-18
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• 2013

Wind turbines should generally be installed at a certain distance from a road to ensure passengers' safety. In Korea, there is no clear guidance as the Ministry of Environment first proposed a road setback distance of 400 m in the Onshore Wind Farm Siting Guidelines draft proposed in July 2012, and then modified it to 1.5 times the height of the wind turbine in October of the same year. This study analyzed the dynamic range of onshore wind resource potential according to how the road setback distance is set using the Korea Wind Atlas with 100m spatial resolution made by the Korea Institute of Energy Research, the transportation network of the Ministry of Construction and Transportation, and the forest road network of the Korea Forestry Service. Owing to the geographical characteristics of Korea, where mountainous terrain accounts for 70% of the total territory, the wind resource potential within 1 km from forest roads are estimated to be 14.3 GW, 14% of Korea's total wind resource potential. In addition, the construction distance of new road for transporting wind turbines from the existing road to a wind farm site is estimated as less than 2 km. Given the limited wind resource potential and geographical constraints, an assessment system that can maximize wind resource utilization and ensure road safety at the same time, and which takes into account the regional characteristics instead of applying the fixed road setback distance across-the-road, is required.

• Wind and Structures
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• v.20 no.2
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• pp.191-211
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• 2015

Several frameworks for the dynamic analysis of wind-vehicle-bridge systems were presented in the past decade to study the safety or ride comfort of road vehicles as they pass through bridges under crosswinds. The wind loads on the vehicles were generally formed based on the aerodynamic parameters of the stationary vehicles on the ground, and the wind loads for the pure bridge decks without the effects of road vehicles. And very few studies were carried out to explore the dynamic effects of the aerodynamic interference between road vehicles and bridge decks, particularly for the moving road vehicles. In this study, the aerodynamic parameters for both the moving road vehicle and the deck considering the mutually-affected aerodynamic effects are formulized firstly. And the corresponding wind loads on the road vehicle-bridge system are obtained. Then a refined analytical framework of the WVB system incorporating the resultant wind loads, a driver model, and the road roughness in plane to fully consider the lateral motion of the road vehicle under crosswinds is proposed. It is shown that obvious lateral and yaw motions of the road vehicle occur. For the selected single road vehicle passing a long span bridge, slight effects are caused by the aerodynamic interference between the moving vehicle and deck on the dynamic responses of the system.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.485-488
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• 2008

The structure supporting road sign is a road information facility for ensuring the safe transportation and smooth traffic. But, lots of road information facilities were damaged by the typhoon "Maemi" in 2003. Such damaged facilities should be rehabilitated and could increase economic loss by causing traffic accident. Therefore, in this study, behavior that reduce wind load and improve wind resistance of the structure supporting road sign are studied about wind load beyond design specification by abnormal climate as below. The first is wind load reducing technique such that shear key resist wind load that is not greater than design wind speed but in case that it is over the design wind limit, column member is rotated on the inner steel pipe axis by the brittle failure of shear key. The second is the technique such that fail-safe the overturning of road sign panel by equipment installation in the vertical member. The third is the technique of installing stiffening plate inside the vertical member to relieve stress concentration.

• Wind and Structures
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• v.19 no.2
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• pp.185-197
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• 2014

Ventilation and fire safety design in road tunnels are one of the most complex issues that need to be carefully considered and analysed in the designing stage of any potential upgrade of ventilation and other fire safety systems in tunnels. Placement road tunnels space has an important influence on fire safety, especially when considering the effect of adverse wind conditions that significantly influence ventilation characteristics. The appropriate analysis of fire and smoke control is almost impossible without the use of modern simulation tools (e.g., CFD) due to a large number of influential parameters and consequently extensive data. The impact of the strong wind is briefly presented in this paper in the case of a longitudinally ventilated road tunnel Kastelec, which is exposed to various severe wind conditions that significantly influence its fire safety. The possibility of using CFD simulations in the analysis of the tunnel placement in space terms negative effect of wind influence on the tunnel ventilation is clearly indicated.

• Wind and Structures
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• v.6 no.5
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• pp.325-346
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• 2003

High-sided road vehicles are susceptible to a sharp-edged crosswind gust, which may cause vehicle accidents such as overturning, excessive sideslip, or exaggerated rotation. This paper thus investigates the dynamic behaviour and possible accidents of high-sided road vehicles entering a sharp-edged crosswind gust with road surface roughness and vehicle suspension included. The high-sided road vehicle is modelled as a combination of several rigid bodies connected by a series of springs and dampers in both vertical and lateral directions. The random roughness of road surface is generated from power spectral density functions for various road conditions. The empirical formulae derived from wind tunnel test results are employed to determine aerodynamic forces and moments acting on the vehicle. After the governing equations of motion are established, an extensive computation work is performed to examine the effects of road surface roughness and vehicle suspension on the dynamic behaviour and vehicle accidents. It is demonstrated that for the high-sided road vehicle and wind forces specified in the computation, the accident vehicle speed of the road vehicle running on the road of average condition is relatively smaller than that running on the road of very good condition for a given crosswind gust. The vehicle suspension system should be taken into consideration, and the accident vehicle speed becomes smaller if the vehicle suspension system has softer springs and lighter dampers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.77-84
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• 2017

Recently, interest in safety has been increasing in every area, especially in the field of transportation. The accurate evaluation of the stability of road facilities is needed to improve the level of safety in the field of transportation and the application of new technologies is required to reduce the number of natural disasters. In this study, the wind data were compared and analyzed according to the type of measurement, and an evaluation of the stability of road signs using the wind data was conducted. In addition, a stability plan to secure road signs was elaborated and its effect on the wind load was analyzed. It was found that the wind data measured by a mobile atmospheric observing system (MAOS) was 2.43 times bigger than that measured by the Korea meteorological administration (KMA) and road weather information system (RWIS). In terms of their stability, the road signs were susceptible to failure caused by gusty winds and it was found necessary to ensure their stability. In the future, it will be possible to evaluate the stability of road facilities using road line weather data and the application of wind load reduction technologies is expected to improve road safety.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.1
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• pp.24-34
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• 2013

This paper introduces the study of hood-type wind turbine embedded on highway median strip. Recently, many studies are being made to apply to small wind turbine in city. This study is wind turbine producing electricity generated from the wind by running cars. In order to analyze wind generated by running cars, we measured experiments using running cars and buses. Also, using CFD and interpreter program, we analysis wind turbines performance and applied to the twist-sabonius blade. This wind turbine attached to safety lamp on the road is produced to use electricity generated through the wind tunnel experiment. In this paper results, this wind turbine system is expected to produce the power source installed the heat ray and safety lamps on the road.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.195-202
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• 2013

PURPOSES : This study analyzed the regional dew possibility in road sign using meteorological data. METHODS : Four years of meteorological data such as temperature, humidity, dew point, wind velocity were collected and analyzed. As a result of literature review, dew was frequent in large diurnal range, high humidity and weak wind. So, dew possibility was analyzed by (temperature-dew point ${\leq}1^{\circ}C$ and wind velocity ${\leq}$ 1.5m/s). RESULTS : The possibility was analyzed for each meteorological observation point and the point of Suncheon and Bonghwa were selected as the most likely points of dew in road sign. The area of East Coast, Kyungbuk and Kyungnam were relatively low potential. CONCLUSIONS : Alternative with high effect of preventing dew should be selected in high possibility dew area despite of low economics.

• Wind and Structures
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• v.18 no.2
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• pp.155-180
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• 2014

The safety of road vehicles on the ground in crosswind has been investigated for many years. One of the most important fundamentals in the safety analysis is aerodynamic characteristics of a vehicle in crosswind. The most common way to study the aerodynamic characteristics of a vehicle in crosswind is wind tunnel tests to measure the aerodynamic coefficients and/or pressure coefficients of the vehicle. Due to the complexity of wind tunnel test equipment and procedure, the features of flow field around the vehicle are seldom explored in a wind tunnel, particularly for the vehicle moving on the ground. As a complementary to wind tunnel tests, the numerical method using computational fluid dynamics (CFD) can be employed as an effective tool to explore the aerodynamic characteristics of as well as flow features around the vehicle. This study explores crosswind effects on a high-sided lorry on the ground with and without movement through CFD simulations together with wind tunnel tests. Firstly, the aerodynamic forces on a stationary lorry model are measured in a wind tunnel, and the results are compared with the previous measurement results. The CFD with unsteady RANS method is then employed to simulate wind flow around and wind pressures on the stationary lorry. The numerical aerodynamic forces are compared with the wind tunnel test results. Furthermore, the same CFD method is extended to investigate the moving vehicle on the ground in crosswind. The results show that the CFD results match with wind tunnel test results and the current way using aerodynamic coefficients from a stationary vehicle in crosswind is acceptable. The CFD simulation can provide more insights on flow field and pressure distribution which are difficult to be obtained by wind tunnel tests.

• Wind and Structures
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• v.23 no.6
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• pp.485-503
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• 2016

To investigate the nonlinear aerostatic stability of the Hutong cable-stayed rail-cum-road bridge with ultra-kilometer main span, a FEM bridge model is established. The tri-component wind loads and geometric nonlinearity are taken into consideration and discussed for the influence of nonlinear parameters and factors on bridge resistant capacity of aerostatic instability. The results show that the effect of initial wind attack-angle is significant for the aerostatic stability analysis of the bridge. The geometric nonlinearities of the bridge are of considerable importance in the analysis, especially the effect of cable sag. The instable mechanism of the Hutong Bridge with a steel truss girder is the spatial combination of vertical bending and torsion with large lateral bending displacement. The design wind velocity is much lower than the static instability wind velocity, and the structural aerostatic resistance capacity can meet the requirement.