• Control of Airborne Noise Generated in the Cavities of a T-Slotted Aluminum Cylindrical Column 

      Mustafa, Mohamad Y.; Yizhong, Xu; Sørensen, Bjørn Reidar; Santos, José; Al-Mahadin, Aziz (Peer reviewed; Chapter, 2018-06-11)
      This paper presents a study of airborne noise generated by a T-slotted cylindrical aluminum hollow column with six slots of the type used for the construction of communication towers. Noise is a very distracting phenomena and an environmental concern caused by various sources. Noise pollution is becoming more severe with the introduction of massive human activities and the use of heavy machineries, ...
    • Modelling Multi-layer Hydronic Radiators 

      Chen, Liguo; Sørensen, Bjørn Reidar (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-30)
      This report simulates Purmo type C22 and C33 radiators with both standard calculation and heat transfer method with help of Matlab/Simulink. Simulation results are presented to describe the radiators’ thermal performances with different simulation strategies. The deviations between two different calculation methods are identified and the heat transfer radiator model can be improved with more ...
    • Numerical Simulation of Non-normal Wind Load on Porous Fences 

      Xu, Yizhong; Mustafa, Mohamad; Calay, Rajnish K; Sørensen, Bjørn Reidar (Journal article; Peer reviewed; Tidsskriftartikkel, 2017)
      This paper presents a numerical simulation of non-normal wind loads on a porous fence. It was found that non-normal wind load has significant impact on the performance of the fence in terms. The performance of the fence was measured as the effective fence zone behind the fence where flow characteristics and normal drag coefficients were maintained within safe level. It is recommended the incidental ...
    • Numerical study on the ventilation performance of a livestock house built in porous panels in Cold Regions 

      Mustafa, Mohamad; Xu, Yizhong; Calay, Rajnish K; Sørensen, Bjørn Reidar (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11)
      This paper presents a numerical prediction on the assessment of natural ventilation on a livestock house built in porous panels, aided by Computational Fluid Dynamics techniques. A typical climatic environment in Cold Regions was taken into consideration. The ventilation performances have been assessed by the distribution of indoor air velocity, turbulence intensity and local mean age of air through ...
    • Numerical study on the ventilation performance of a livestock house built in porous panels in Cold Regions 

      Xu, Yizhong; Mustafa, Mohamad; Calay, Rajnish K; Sørensen, Bjørn Reidar (Journal article; Tidsskriftartikkel; Peer reviewed, 2019)
      This paper presents a numerical prediction on the assessment of natural ventilation on a livestock house built in porous panels, aided by Computational Fluid Dynamics techniques. A typical climatic environment in Cold Regions was taken into consideration. The ventilation performances have been assessed by the distribution of indoor air velocity, turbulence intensity and local mean age of air through ...
    • Soil Moisture Variations in Frozen Ground Subjected to Hydronic Heating 

      Sveen, Svein Erik; Nguyen, Hung Thanh; Sørensen, Bjørn Reidar (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-10)
      Full-scale thawing experiments, performed on three types of homogenous, initially frozen soils, were carried out during late winter 2011 and repeated in 2012. An auxiliary heat source (hydronic heating) was employed to initiate and expedite the thawing process. The corresponding phase change, soil temperature increase, and variations in bound and unbound water content were monitored during the ...
    • Thaw Penetration in Frozen Ground Subjected to Hydronic Heating 

      Sveen, Svein Erik; Nguyen, Hung Thanh; Sørensen, Bjørn Reidar (Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-09-22)
      To facilitate excavation and foundation work in seasonally freezing or permafrost regions, the frozen soil must be thawed, either by natural (solar) thawing, or by artificial thawing where an auxiliary heat source is utilized to accelerate the process. In this paper, the process of rapid thawing of frozen ground subject to hydronic heating is studied. In particular, the performance characteristics ...
    • Variation of Mean Radiant Temperature in Rooms for Summer and Winter Conditions 

      Tamrakar, Stutee; Chen, Liguo; Sørensen, Bjørn Reidar (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-25)
      The standard for ergonomics of the thermal environment provides information on the calculation of optimal thermal comfort. Operative temperature (OT) is one of the essential elements of thermal comfort and is a function of air temperature, mean radiant temperature (MRT), and air velocity. This paper investigates the impact of diverse influences on MRT in an office room based on occupant position ...
    • Ventilation and environmental control of underground spaces: A short review 

      Li, Angui; Kosonen, Risto; Melikov, Arsen; Yang, Bin; Olofsson, Thomas; Sørensen, Bjørn Reidar; Zhang, Linhua; Cui, Ping; Han, Ou (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-13)
      More and more underground spaces were used in 21st century because of rapid urbanization, traffic problems, etc. Underground city, metro, tunnel, mine, industrial and agriculture engineering, civil air defence engineering need large underground spaces. Underground spaces with different thermal, ventilation and lighting environments may cause comfort, health and safety problems. Concrete problems ...