The Development of a Multi-Purpose Wind Tunnel

Harun, Zambri; Ghopa, Wan Aizon Wan; Abdullah, Shahrir; Ghazali, Mohd Shafiq Mat; Abbas, Ashraf A.; Rasani, Mohammad Rasidi Mohammad; Zulkifli, Rozli; Mahmood, Wan Mohd Faizal Wan; Mansor, Mohd Radzi Abu; Abidin, Zulkhairi Zainol; Mohtar, Wan Hanna Melini Wan

doi:10.11113/jt.v78.9189

Cited by 7 publications

(8 citation statements)

References 20 publications

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“…Station UKM01 and UKM02 belong to the university (UKM), therefore it is possible to provide uncertainty estimates of the data acquired from these stations. For wind speed, calibration for the ultrasonic anemometer was performed at UKM wind tunnel [22]. The temperature calibrations were done in-situ using the portable device UNI-T series UT-363.…”

Section: Uncertainty Analysismentioning

confidence: 99%

Variation of the Urban Heat Island Intensity over One Year in Putrajaya, Malaysia

Harun¹,

Azhar²,

Abbas³

et al. 2022

JMechE

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This research was conducted to evaluate the variation of the urban heat island (UHI) effects in the planned city of Putrajaya over one year. Putrajaya, the administrative capital of Malaysia, is known for its meticulous town planning. The main observations are temperature variation, the changes in wind speed, percentage of relative humidity, and subsequently, the intensity of UHI in the research area. Putrajaya Corporation Complex Precinct 3 (P3) and Precinct 9 (P9) are located in the central business district (CBD) and residential areas respectively. These two places are representatives of UHI's effects on CBD and residential areas. Ultrasonic anemometers which measure 3 components of wind velocities and temperature were employed to analyse temperature and wind patterns. The result indicates the city experienced high temperatures during the day causing human heat stress and discomfort. The UHI intensities of the city are within the range of temperature differences 2 to 3 °C. Land surface cover and numbers of the population are the vital effects of the UHI. Thus, strategies to reduce the existing high air and surface temperature are required in the future.

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Section: Uncertainty Analysismentioning

confidence: 99%

Variation of the Urban Heat Island Intensity over One Year in Putrajaya, Malaysia

Harun¹,

Azhar²,

Abbas³

et al. 2022

JMechE

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“…Ventilation velocity is controlled and calibrated by varying the voltage using a Toshiba frequency inverter VF-S11. The fan speed is calibrated with existing pitot tube and pressure transducer and having access at the wind tunnel located in the Beach and Water Resources Engineering Laboratory, National University of Malaysia (UKM) (Harun et al 2016) made the calibration procedures easily accomplished. A section of 60-cm-long flow strengtheners including two metal mesh screens and a honeycomb mesh, is located between the fan and the test section for uniform longitudinal ventilation.…”

Section: Model Tunnelmentioning

confidence: 99%

Experimental Investigation on the Influences of Different Horizontal Fire Locations on Smoke Temperature Stratification under Tunnel Ceiling

Haddad¹,

Zulkifli²,

Maluk³

et al. 2020

JAFM

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The increased probability of fire occurrence in urban tunnels has led researchers to investigate this issue extensively. Although fire can occur at any point in a tunnel, the effect of fire source position on temperature distribution has not received considerable attention in most of previous investigations. In this research, the influences of varying horizontal fire source locations on temperature diffusion in particular maximum smoke temperature stratification beneath the ceiling has been investigated. A set of scale-down experiments was performed in a model tunnel [3 m (length) × 0.6 m (width) × 0.96 m (height)]. n-Heptane and gasoline were used as fuels in rectangular pools to generate a heat source. The analysis reveals that typical temperature curves have a similar trend when the fire source location changes. Furthermore, the temperature profile tip (maximum smoke temperature) is located between the burner and the origin of the tunnel. The modified model of maximum temperature, which considers the horizontal fire source location, is defined. The results here complement existing literature where the effects of variable fire position in a tunnel have not been considered.

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“…The CSAT-3B anemometer was connected to the PC through a CR1000 data logger (Campbell Scientific, USA), whereas the YOUNG 81000 anemometer was directly connected to the PC. Both anemometers were calibrated in the UKM low speed wind tunnel [26] before the experiment and an error of less than 2% was achieved. The sonic temperature can be set equal to the virtual potential temperature with a minimal error [27][28][29].…”

Section: Site and Instrumentsmentioning

confidence: 99%

Modulation of the atmospheric turbulence coherent structures by mesoscale motions

Lotfy

Zaki

Harun

2018

J Braz. Soc. Mech. Sci. Eng.

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The precise modeling of turbulence is indispensable for weather forecasting and environmental heat-removal and pollution-dispersion assessment. Models rely on correlations derived from field measurements. Unfortunately, the readings are usually contaminated with mesoscale motions which alter turbulence statistics and mislead the characterization of turbulence coherent structures, the drivers of the heat and mass transport process. This article depicts the interference of the mesoscales in turbulence statistics and coherent structure detection. Atmospheric measurements were taken at EKOMAR on the east coast of Malaysia. Two ultrasonic anemometers at heights of 1.7 and 12 m were utilized. Twelve samples from the convective atmospheric boundary layer were analyzed. Spectral and auto-correlation analysis were conducted to assess the weight of the mesoscales relative to the shear coherent structure scales. The structure inclination angle and timescale were calculated for the wind speed signal with and without the mesoscale scales filtered out. It was found that these interfering structures largely shifts the calculated length-and timescales of the coherent structures. The improper filtration of the signal may delete part of the coherent structures and hence worsen the situation.

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The Development of a Multi-Purpose Wind Tunnel

Cited by 7 publications

References 20 publications

Variation of the Urban Heat Island Intensity over One Year in Putrajaya, Malaysia

Variation of the Urban Heat Island Intensity over One Year in Putrajaya, Malaysia

Experimental Investigation on the Influences of Different Horizontal Fire Locations on Smoke Temperature Stratification under Tunnel Ceiling

Modulation of the atmospheric turbulence coherent structures by mesoscale motions

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