对撞射流下通风空间的流场结构实验研究
摘要：为了研究送风口和回风口位置对室内流场结构的影响，本文搭建了采用多条缝对置撞击送风的通风缩比模型实验平台，利用激光粒子测速技术研究了等温和非等温工况下多条缝通风空间中不稳定气流场的速度和湍流信息。结果表明：等温和非等温工况下，送风口截面的流场速度、湍动能和涡量的空间分布类似，最大值分别可以达到1.3 m/s、0.1 m2/s2和60 s-1,射流碰撞形成2个大尺度涡旋，造成流场结构不稳定；CS4.5截面，流场速度、湍动能和涡量最大值分别可以达到0.9 m/s、0.04 m2/s2和30 s-1;CS3.5截面，速度与涡量最大值均出现在近壁面附近，分别为0.42 m/s、8 s-1,湍动能最大值出现在截面中间位置，为0.13 m2/s2,且流场中形成了大规模的涡旋；非等温工况下，送风口截面和CS3.5截面中小尺度涡旋增加，大尺度涡旋减少，热羽流抑制了大尺度流场结构，增加了小尺度流场结构。
关键词：对撞射流通风空间流场结构等温工况非等温工况速度湍动能涡量
尊敬的用户，本篇文章需要2元，点击支付交费后阅读
限时优惠福利：领取VIP会员
全年期刊、VIP视频免费!
全年期刊、VIP视频免费!
参考文献[1] SPENGLER J D,SEXTON K.Indoor air pollution:a public health perspective[J].Science,1983,221(4605):9- 17.
[2] TANG J W,MARR L C,LI Y,et al.COVID-19 has redefined airborne transmission[J].BMJ,2021,373:n913.
[3] MORAWSKA L,ALLEN J,BAHNFLETH W,et al.A paradigm shift to combat indoor respiratory infection[J].Science,2021,372(6543):689- 691.
[4] CHEN Q Y.Ventilation performance prediction for buildings:a method overview and recent applications[J].Building and environment,2009,44(4):848- 858.
[5] LIDDAMENT M W.A review of ventilation and the quality of ventilation air[J].Indoor air,2000,10(3):193- 199.
[6] CAO G Y,AWBI H,YAO R M,et al.A review of the performance of different ventilation and airflow distribution systems in buildings[J].Building and environment,2014,73:171- 186.
[7] KOSUTOVA K,VAN HOOFF T,BLOCKEN B.CFD simulation of non-isothermal mixing ventilation in a generic enclosure:impact of computational and physical parameters[J].International journal of thermal sciences,2018,129:343- 357.
[8] NIELSEN P V,RESTIVO A,WHITELAW J H.The velocity characteristics of ventilated rooms[J].Journal of fluids engineering,1978,100(3):291.
[9] MOUREH J,FLICK D.Wall air-jet characteristics and airflow patterns within a slot ventilated enclosure[J].International journal of thermal sciences,2003,42(7):703- 711.
[10] MOUREH J,FLICK D.Airflow characteristics within a slot-ventilated enclosure[J].International journal of heat and fluid flow,2005,26(1):12- 24.
[11] VAN HOOFF T,BLOCKEN B,DEFRAEYE T,et al.PIV measurements of a plane wall jet in a confined space at transitional slot Reynolds numbers[J].Experiments in fluids,2012,53(2):499- 517.
[12] VAN HOOFF T,BLOCKEN B,DEFRAEYE T,et al.PIV measurements and analysis of transitional flow in a reduced-scale model:ventilation by a free plane jet with Coanda effect[J].Building and environment,2012,56:301- 313.
[13] HOFF S J,JANNI K A,JACOBSON L D.Three-dimensional buoyant turbulent flows in a scaled model,slot-ventilated,livestock confinement facility[J].Transactions of the ASAE,1992,35(2):671- 686.
[14] HJERTAGER B H,MAGNUSSEN B F.Calculation of turbulent three-dimensional jet induced flow in rectangular enclosures[J].Computers & fluids,1981,9(4):395- 407.
[15] ADRE N,ALBRIGHT L D.Criterion for establishing similar air flow patterns (isothermal) in slotted-inlet ventilated enclosures[J].Transactions of the ASAE,1994,37(1):235- 250.
[16] YU H,HOFF S J.Airflow pattern similarity criteria for ceiling slot-ventilated agricultural enclosures under isothermal conditions[J].Transactions of the ASAE,1999,42(2):459- 469.
[17] ZHANG G,MORSING S,BJERG B,et al.Test room for validation of airflow patterns estimated by computational fluid dynamics[J].Journal of agricultural engineering research,2000,76(2):141- 148.
[18] KARIMIPANAH M T.Deflection of wall-jets in ventilated enclosures described by pressure distribution[J].Building and environment,1998,34(3):329- 333.
[19] AWBI H B.Application of computational fluid dynamics in room ventilation[J].Building and environment,1989,24(1):73- 84.
[20] GAN G,AWBI H B.Numerical simulation of the indoor environment[J].Building and environment,1994,29(4):449- 459.
[21] DAVIDSON L.Ventilation by displacement in a three-dimensional room:a numerical study[J].Building and environment,1989,24(4):363- 372.
[22] MACIAS-MELO E V,AGUILAR-CASTRO K M,XAMÁN J,et al.Experimental study of convective heat transfer in a ventilated rectangular cavity[J].Journal of building physics,2018,42(3):388- 415.
[23] CAO S J,DENG H Y,ZHOU X,et al.Ventilation inlets design based on ventilation performance assessment using a dimensionless time scale[J].Indoor and built environment,2019,28(8):1049- 1063.
[24] CHANG Z Y,YI K,LIU W W.A new ventilation mode of air conditioning in subway vehicles and its air distribution performance[J].Energy and built environment,2021,2(1):94- 104.
[25] YANG L,LI M X,LI X D,et al.The effects of diffuser type on thermal flow and contaminant transport in high-speed train (HST) cabins:a numerical study[J].International journal of ventilation,2018,17(1):48- 62.
[26] WANG H T,LIN M D,CHEN Y.Performance evaluation of air distribution systems in three different China railway high-speed train cabins using numerical simulation[J].Building simulation,2014,7(6):629- 638.
[27] WANG C C,ZHANG J,CHEN H B,et al.Experimental study of thermo-fluid boundary conditions,airflow and temperature distributions in a single aisle aircraft cabin mockup[J].Indoor and built environment,2021,30(8):1185- 1199.
[28] WANG C C,ZHANG J,CHAO J Y,et al.Evaluation of dynamic airflow structures in a single-aisle aircraft cabin mockup based on numerical simulation[J].Indoor and built environment,2022,31(2):398- 413.
[29] WANG C C,LIU J J,SHANG W J,et al.Experimental and numerical study of space station airflow distribution under microgravity condition[J].Building and environment,2018,144:268- 280.
[30] NIELSEN P V.Fifty years of CFD for room air distribution[J].Building and environment,2015,91:78- 90.
[2] TANG J W,MARR L C,LI Y,et al.COVID-19 has redefined airborne transmission[J].BMJ,2021,373:n913.
[3] MORAWSKA L,ALLEN J,BAHNFLETH W,et al.A paradigm shift to combat indoor respiratory infection[J].Science,2021,372(6543):689- 691.
[4] CHEN Q Y.Ventilation performance prediction for buildings:a method overview and recent applications[J].Building and environment,2009,44(4):848- 858.
[5] LIDDAMENT M W.A review of ventilation and the quality of ventilation air[J].Indoor air,2000,10(3):193- 199.
[6] CAO G Y,AWBI H,YAO R M,et al.A review of the performance of different ventilation and airflow distribution systems in buildings[J].Building and environment,2014,73:171- 186.
[7] KOSUTOVA K,VAN HOOFF T,BLOCKEN B.CFD simulation of non-isothermal mixing ventilation in a generic enclosure:impact of computational and physical parameters[J].International journal of thermal sciences,2018,129:343- 357.
[8] NIELSEN P V,RESTIVO A,WHITELAW J H.The velocity characteristics of ventilated rooms[J].Journal of fluids engineering,1978,100(3):291.
[9] MOUREH J,FLICK D.Wall air-jet characteristics and airflow patterns within a slot ventilated enclosure[J].International journal of thermal sciences,2003,42(7):703- 711.
[10] MOUREH J,FLICK D.Airflow characteristics within a slot-ventilated enclosure[J].International journal of heat and fluid flow,2005,26(1):12- 24.
[11] VAN HOOFF T,BLOCKEN B,DEFRAEYE T,et al.PIV measurements of a plane wall jet in a confined space at transitional slot Reynolds numbers[J].Experiments in fluids,2012,53(2):499- 517.
[12] VAN HOOFF T,BLOCKEN B,DEFRAEYE T,et al.PIV measurements and analysis of transitional flow in a reduced-scale model:ventilation by a free plane jet with Coanda effect[J].Building and environment,2012,56:301- 313.
[13] HOFF S J,JANNI K A,JACOBSON L D.Three-dimensional buoyant turbulent flows in a scaled model,slot-ventilated,livestock confinement facility[J].Transactions of the ASAE,1992,35(2):671- 686.
[14] HJERTAGER B H,MAGNUSSEN B F.Calculation of turbulent three-dimensional jet induced flow in rectangular enclosures[J].Computers & fluids,1981,9(4):395- 407.
[15] ADRE N,ALBRIGHT L D.Criterion for establishing similar air flow patterns (isothermal) in slotted-inlet ventilated enclosures[J].Transactions of the ASAE,1994,37(1):235- 250.
[16] YU H,HOFF S J.Airflow pattern similarity criteria for ceiling slot-ventilated agricultural enclosures under isothermal conditions[J].Transactions of the ASAE,1999,42(2):459- 469.
[17] ZHANG G,MORSING S,BJERG B,et al.Test room for validation of airflow patterns estimated by computational fluid dynamics[J].Journal of agricultural engineering research,2000,76(2):141- 148.
[18] KARIMIPANAH M T.Deflection of wall-jets in ventilated enclosures described by pressure distribution[J].Building and environment,1998,34(3):329- 333.
[19] AWBI H B.Application of computational fluid dynamics in room ventilation[J].Building and environment,1989,24(1):73- 84.
[20] GAN G,AWBI H B.Numerical simulation of the indoor environment[J].Building and environment,1994,29(4):449- 459.
[21] DAVIDSON L.Ventilation by displacement in a three-dimensional room:a numerical study[J].Building and environment,1989,24(4):363- 372.
[22] MACIAS-MELO E V,AGUILAR-CASTRO K M,XAMÁN J,et al.Experimental study of convective heat transfer in a ventilated rectangular cavity[J].Journal of building physics,2018,42(3):388- 415.
[23] CAO S J,DENG H Y,ZHOU X,et al.Ventilation inlets design based on ventilation performance assessment using a dimensionless time scale[J].Indoor and built environment,2019,28(8):1049- 1063.
[24] CHANG Z Y,YI K,LIU W W.A new ventilation mode of air conditioning in subway vehicles and its air distribution performance[J].Energy and built environment,2021,2(1):94- 104.
[25] YANG L,LI M X,LI X D,et al.The effects of diffuser type on thermal flow and contaminant transport in high-speed train (HST) cabins:a numerical study[J].International journal of ventilation,2018,17(1):48- 62.
[26] WANG H T,LIN M D,CHEN Y.Performance evaluation of air distribution systems in three different China railway high-speed train cabins using numerical simulation[J].Building simulation,2014,7(6):629- 638.
[27] WANG C C,ZHANG J,CHEN H B,et al.Experimental study of thermo-fluid boundary conditions,airflow and temperature distributions in a single aisle aircraft cabin mockup[J].Indoor and built environment,2021,30(8):1185- 1199.
[28] WANG C C,ZHANG J,CHAO J Y,et al.Evaluation of dynamic airflow structures in a single-aisle aircraft cabin mockup based on numerical simulation[J].Indoor and built environment,2022,31(2):398- 413.
[29] WANG C C,LIU J J,SHANG W J,et al.Experimental and numerical study of space station airflow distribution under microgravity condition[J].Building and environment,2018,144:268- 280.
[30] NIELSEN P V.Fifty years of CFD for room air distribution[J].Building and environment,2015,91:78- 90.
Experimental study on flow field structure of ventilation space under colliding jets
Abstract: In order to study the influence of the positions of the air supply outlet and return outlet on the indoor flow field structure, this paper builds a ventilation scale model experiment platform using multiple slots to impinge air supply, and uses the particle image velocimetry technique to study the velocity and turbulence information of the unstable airflow field in the multiple slot ventilation space under isothermal and non-isothermal conditions.The results show that under isothermal and non-isothermal conditions, the spatial distributions of flow field velocity, turbulent kinetic energy and vorticity in the air supply outlet section are similar, and the maximum values can reach 1.3 m/s, 0.1 m2/s2 and 60 s-1, respectively. Two large-scale vortices are formed due to jet impingement, resulting in unstable flow field structure. In the CS4.5 section, the maximum flow field velocity, turbulent kinetic energy and vorticity can reach 0.9 m/s, 0.04 m2/s2 and 30 s-1, respectively. In the CS3.5 section, the maximum velocity and vorticity appear near the wall, which are 0.42 m/s and 8 s-1, respectively, the maximum turbulent kinetic energy appears in the middle of the section, it is 0.13 m2/s2, and the large scale vortices are formed in the flow field.Under the non-isothermal condition, the medium and small scale vortices of the air supply outlet section and the CS3.5 section increase, while the large scale vortice decreases. Therefore, the thermal plume inhibits the large scale flow field structure and increases the small scale flow field structure.
Keywords: colliding jet; ventilation space; flow field structure; isothermal condition; non-isothermal condition; velocity; turbulent kinetic energy; vorticity;
200
0
0