Design and performance comparison of two patterns of wind-catcher for a semi-enclosed courtyard

The main focal point of this work is to provide an enhanced indoor air quality (IAQ) using natural ventilation system called wind-catcher and also to cut the energy consumed by mechanical HVAC systems. This paper looks into the operation of two patterns of wind-catcher in a semienclosed courtyard on the top level of the engineering school at Sultan Qaboos University, Oman. The wind speed, direction and roughness length in the region of SQU were used as the inlet and boundary conditions. Computational Fluid Dynamics (CFD) analysis was performed using ANSYS FLUENT with a standard k-epsilon model to generate a homogenous neutral ABL at the inlet. This study provides a comparison of airflow distribution inside the courtyard with two modified wind-catcher designs to provide better indoor air quality. The primary focus is on the air stream distribution. The best possible flow rate of 6056 L/s was achieved for reference velocity 4 m/s at reference height 50m. This rate is more eminent than the minimum requirement suggested by ASHRAE standard 62.1-2013. Also air change per hour (ACH) for the same condition was around 108.

[1]  T. Stathopoulos,et al.  CFD simulation of the atmospheric boundary layer: wall function problems , 2007 .

[2]  Saleh M. Al-Alawi,et al.  Assessment of wind energy potential locations in Oman using data from existing weather stations , 2010 .

[3]  Cheuk Ming Mak,et al.  The assessment of the performance of a windcatcher system using computational fluid dynamics , 2007 .

[4]  E. Bilgen,et al.  Numerical study of solar-wind tower systems for ventilation of dwellings , 2008 .

[5]  John Kaiser Calautit,et al.  CFD and wind tunnel study of the performance of a uni-directional wind catcher with heat transfer devices , 2015 .

[6]  P. Richards,et al.  Appropriate boundary conditions for computational wind engineering models using the k-ε turbulence model , 1993 .

[7]  Azeddine Belhamri,et al.  Performance analysis and improvement of the use of wind tower in hot dry climate , 2011 .

[8]  D. Asimakopoulos.  Passive Cooling of Buildings , 1996 .

[9]  Ray Kirby,et al.  Quantifying the performance of a top-down natural ventilation Windcatcher™ , 2009 .

[10]  Kamaruzzaman Sopian,et al.  Review of windcatcher technologies , 2012 .

[11]  Kamaruzzaman Sopian,et al.  Design configurations analysis of wind-induced natural ventilation tower in hot humid climate using computational fluid dynamics , 2015 .

[12]  H Hamid Montazeri,et al.  Two-sided wind catcher performance evaluation using experimental, numerical and analytical modeling , 2010 .

[13]  Abbas Elmualim,et al.  Effect of damper and heat source on wind catcher natural ventilation performance , 2006 .

[14]  Abbas Elmualim,et al.  Dynamic modelling of a wind catcher/tower turret for natural ventilation , 2006 .

[15]  Mohd. Farid Mohamed,et al.  Performance Evaluation of Four-Sided Square Wind Catchers with Different Geometries by Numerical Method , 2013 .

[16]  John Kaiser Calautit,et al.  Measurement and prediction of the indoor airflow in a room ventilated with a commercial wind tower , 2014 .

[17]  H. Ahmadikia,et al.  Performance Analysis of a Wind-Catcher With Water Spray , 2012 .

[18]  Mohd. Farid Mohamed,et al.  Computational Analysis of Wind-Driven Natural Ventilation in a Two Sided Rectangular Wind Catcher , 2013 .

[19]  Hamid Saffari,et al.  Effects of different internal designs of traditional wind towers on their thermal behavior , 2013 .

[20]  Ishwar Chand,et al.  Studies on the Design and Performance of Wind Catchers , 1990 .

[21]  Ben Richard Hughes,et al.  A study of wind and buoyancy driven flows through commercial wind towers , 2011 .

[22]  Nicolas G. Wright,et al.  On the use of the k–ε model in commercial CFD software to model the neutral atmospheric boundary layer , 2007 .

[23]  Ervin Bossanyi,et al.  Wind Energy Handbook , 2001 .

[24]  J. E. Janssen,et al.  Ventilation for acceptable indoor air quality , 1989 .

[25]  Yuehong Su,et al.  Experimental and CFD study of ventilation flow rate of a Monodraught™ windcatcher , 2008 .

[26]  Adolf Acquaye,et al.  Integrating economic considerations with operational and embodied emissions into a decision support system for the optimal ranking of building retrofit options , 2014 .

[27]  M. Dehghan Manshadi,et al.  An experimental study on the evaluation of natural ventilation performance of a two-sided wind-catcher for various wind angles , 2016 .