Experimental investigation of the flow behavior of an isothermal impinging jet in a closed cabin

Abstract The impinging jet concept has been proposed as a new ventilation strategy for use in office and industrial buildings. To improve the performance of impinging jet ventilation system to create a better thermal comfort environment, quantifying the detailed information of the flow behavior of impinging jet should be an essential prerequisite. This study reports an experimental study of an isothermal turbulent jet impinging normally on a flat surface in a closed cabin. The air jet issued from a round pipe with an inner diameter D . The distance between the pipe exit and the flat impingement plate was 9D. The Reynolds number, based on the jet centerline velocity at pipe exit and the pipe inner diameter, was 10,338. Measurements were performed in the free- and wall-jets using cross hot-wire anemometry, mean velocity, turbulence intensity, and power spectrum results being presented. In addition, a multi-scale analysis technique based on empirical mode decomposition was used to analyze and gain deeper insight into the multi-scale characteristics of coherent structures of the jet impingement on flat surface.

[1]  Mats Sandberg,et al.  A comparative study of different air distribution systems in a classroom , 2000 .

[2]  Koichi Nishino,et al.  Turbulence statistics in the stagnation region of an axisymmetric impinging jet flow , 1996 .

[3]  Kevin Knowles,et al.  Turbulence measurements in radial wall-jets , 1998 .

[4]  Tim Craft,et al.  Impinging jet studies for turbulence model assessment—II. An examination of the performance of four turbulence models , 1993 .

[5]  Bahram Moshfegh,et al.  Impinging jet – A new ventilation strategy for industries: a case study of a light alloy foundry , 2009 .

[6]  U. Frisch Turbulence: The Legacy of A. N. Kolmogorov , 1996 .

[7]  Nallamuthu Rajaratnam,et al.  Impinging Circular Turbulent Jets , 1974 .

[8]  Paulo Gonçalves,et al.  Empirical Mode Decompositions as Data-Driven Wavelet-like Expansions , 2004, Int. J. Wavelets Multiresolution Inf. Process..

[9]  A. Kolmogorov Dissipation of energy in the locally isotropic turbulence , 1941, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[10]  Tin-Tai Chow,et al.  Comparison of annual energy performances with different ventilation methods for cooling , 2011 .

[11]  Coleman duP. Donaldson,et al.  A study of free jet impingement. Part 1. Mean properties of free and impinging jets , 1971, Journal of Fluid Mechanics.

[12]  Coleman duP. Donaldson,et al.  A study of free jet impingement. Part 2. Free jet turbulent structure and impingement heat transfer , 1971, Journal of Fluid Mechanics.

[13]  André Garon,et al.  Experimental investigation of the wall shear stress and the vortex dynamics in a circular impinging jet , 2012 .

[14]  N. Huang,et al.  A study of the characteristics of white noise using the empirical mode decomposition method , 2004, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[15]  Peter Davidson,et al.  Turbulence: An Introduction for Scientists and Engineers , 2015 .

[16]  Hachimi Fellouah,et al.  The velocity spectra and turbulence length scale distributions in the near to intermediate regions of a round free turbulent jet , 2009 .

[17]  P. Fanger,et al.  Air turbulence and sensation of draught , 1988 .

[18]  Khaled H. Hamed,et al.  Time-frequency analysis , 2003 .

[19]  K. F. Fong,et al.  Comparison of annual energy performances with different ventilation methods for temperature and humi , 2011 .

[20]  Mathias Cehlin,et al.  Computational investigation on the factors influencing thermal comfort for impinging jet ventilation , 2013 .

[21]  Bahram Moshfegh,et al.  Numerical predictions of indoor climate in large industrial premises. A comparison between different k–ε models supported by field measurements , 2007 .

[22]  Arsen Krikor Melikov Local thermal discomfort due to draft and vertical temperature difference in rooms with displacement ventilation , 1989 .

[23]  M. Tummers,et al.  Turbulent flow in the near field of a round impinging jet , 2011 .

[24]  Dennis Cooper,et al.  Impinging jet studies for turbulence model assessment—I. Flow-field experiments , 1993 .

[25]  Nallamuthu Rajaratnam,et al.  IMPINGEMENT OF AXISYMMETRIC DEVELOPING JETS , 1977 .

[26]  Arsen Krikor Melikov,et al.  Equivalent frequency - a new parameter for description of frequency characteristics of airflow fluctuations , 2002 .

[27]  Dae Hee Lee,et al.  Turbulent flow and heat transfer characteristics of a two-dimensional oblique plate impinging jet , 1997 .

[28]  A Melikov,et al.  Field study on occupant comfort and the office thermal environment in rooms with displacement ventilation. , 2005, Indoor air.

[29]  S. S. Shen,et al.  A confidence limit for the empirical mode decomposition and Hilbert spectral analysis , 2003, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[30]  Hachimi Fellouah,et al.  The flow field in turbulent round free jets , 2012 .

[31]  Mathias Cehlin,et al.  Numerical investigation of the flow behavior of an isothermal impinging jet in a room , 2012 .

[32]  A. N. Kolmogorov Equations of turbulent motion in an incompressible fluid , 1941 .

[33]  Seyed G. Saddoughi,et al.  Local isotropy in turbulent boundary layers at high Reynolds number , 1994, Journal of Fluid Mechanics.

[34]  Gabriel Rilling,et al.  Empirical mode decomposition as a filter bank , 2004, IEEE Signal Processing Letters.

[35]  Kui Soon Kim An experimental study on the flow and heat transfer characteristics of an impinging jet , 1993 .

[36]  Ertan Baydar,et al.  Confined impinging air jet at low Reynolds numbers , 1999 .

[37]  Youngjun Cho,et al.  Theoretical and experimental investigation of impinging jet ventilation and comparison with wall displacement ventilation , 2002 .

[38]  Graham K. Hargrave,et al.  Experimental investigation of an axisymmetric, impinging turbulent jet. 1. Velocity field , 2002 .

[39]  Qingyan Chen,et al.  A critical review of displacement ventilation , 1998 .

[40]  N. Huang,et al.  The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis , 1998, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[41]  Mathias Cehlin,et al.  Investigation on the flow and thermal behavior of impinging jet ventilation systems in an office with different heat loads , 2013 .

[42]  A. Kolmogorov The local structure of turbulence in incompressible viscous fluid for very large Reynolds numbers , 1991, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[43]  N. Huang,et al.  A new view of nonlinear water waves: the Hilbert spectrum , 1999 .

[44]  Nallamuthu Rajaratnam,et al.  PLANE TURBULENT IMPINGING JETS , 1973 .