加齿调控个性化风口流场多尺度湍涡结构的实验研究
|
摘要
客机座舱个性化风口是座舱环控系统中重要的送风单元,其主要作用为快速通风、换热,对乘客的热舒适起到改善作用,但现有个性化送风常引起乘客头部的强烈吹风感。本文通过对现有个性化风口进行边缘加齿的优化设计,调控风口流场中不同尺度的湍涡成分,降低吹风感,从而获得使人体更为舒适的气流流场。实验中使用高时间分辨率热线风速仪,精细测量安装不同尺寸加齿喷嘴的风口流场,采用子波分析的方法对流场多尺度湍涡成分进行分析,对比不同尺寸大小的加齿喷嘴对个性化风口流场多尺度湍涡成分的调控效果,得出齿尖间距离为5mm时,个性化风口的送风使人体更舒适。个性化风口圆环射流经过加齿调控,增强了动量、能量和质量交换,降低了含能尺度的湍流强度,从而降低了吹风感,提高了流场的舒适性。
In aircraft cabin,the personal gasper plays a significant role in the environment control system.It improves the thermal comfort of passengers and enhances the ventilations and heat exchanges.However,the personal gasper currently in use always brings about uncomfortable draft sensation to the passenger's head.In this paper,the personal gasper is optimized by fixing wedges with different sizes at the nozzle,so that it can adjust and control the multi-scale turbulent eddy structures in the jet flow filed and reduce the uncomfortable draft sensation.The constant-temperature anemometer with the hot-wire probe was employed to finely measure the turbulent jet flow field with high time resolution and evaluate the turbulent level of the personal gasper with wedges.The acquired time series of the instantaneous velocity are decomposed by wavelet analysis to extract the multi-scale turbulent eddy structures,and the effects with and without wedges of different sizes are compared.The 5 mm wedges structure is highlighted,which has the most optimal effect and the most comfortable sensation to passengers.By the adjustment and control of wedges,the momentum,energy,mass exchanges of the turbulent jet flow are enhanced,the turbulent level is reduced,the draft sensation deceases and the comfortability is improved.
In aircraft cabin,the personal gasper plays a significant role in the environment control system.It improves the thermal comfort of passengers and enhances the ventilations and heat exchanges.However,the personal gasper currently in use always brings about uncomfortable draft sensation to the passenger's head.In this paper,the personal gasper is optimized by fixing wedges with different sizes at the nozzle,so that it can adjust and control the multi-scale turbulent eddy structures in the jet flow filed and reduce the uncomfortable draft sensation.The constant-temperature anemometer with the hot-wire probe was employed to finely measure the turbulent jet flow field with high time resolution and evaluate the turbulent level of the personal gasper with wedges.The acquired time series of the instantaneous velocity are decomposed by wavelet analysis to extract the multi-scale turbulent eddy structures,and the effects with and without wedges of different sizes are compared.The 5 mm wedges structure is highlighted,which has the most optimal effect and the most comfortable sensation to passengers.By the adjustment and control of wedges,the momentum,energy,mass exchanges of the turbulent jet flow are enhanced,the turbulent level is reduced,the draft sensation deceases and the comfortability is improved.
引文
[1]Guo Y,Jiang N,Yao S,et al.Turbulence measurements of a personal airflow outlet jet in aircraft cabin[J].Building&Environment,2014,82:608-617.
[2]Cao X,Liu J,Pei J,et al.2D-PIV measurement of aircraft cabin air distribution with a high spatial resolution[J].Building&Environment,2014,82(82):9-19.
[3]王维,姜楠,曹晓东,等.MD-82飞机客舱环境流场的HWA测量与分析[J].天津大学学报(自然科学与工程技术版),2013,46(1):2-7.Wang W,Jiang N,Cao X D,et al.HWA measurement and analysis of fluid field in MD-82aircraft cabin[J].Journal of Tianjin University(Natural Science and Engineering Technology),2013,46(1):2-7.
[4]Anderson M D.Effect of gaspers on airflow patterns and the transmission of airborne contaminants within an aircraft cabin environment[D].Kansas Satate University,2010.
[5]Liu W,Mazumdar S,Zhang Z,et al.State-of-the-art methods for studying air distributions in commercial airliner cabins[J].Building&Environment,2012,47:5-12.
[6]Li J,Liu J,Cao X,et al.Experimental study of transient air distribution of a jet collision region in an aircraft cabin mock-up[J].Energy&Buildings,2016,127:786-793.
[7]Zaman K B M Q.Control of an axisymmetric jet using vortex generators[J].Physics of Fluids,1994,6(2):778-793.
[8]刘欣.加小突片喷口射流增强混合的机理研究[D].天津:天津大学,2007.Liu X.A mechanism research about jet mixing enhancement by tabbed nozzle[D].Tianjin:Tianjin University,2007.
[9]张兆顺.湍流[M].北京:国防工业出版社,2002.Zhang Z S.Turbulence[M].Beijing:National Defence Industry Press,2002.
[10]董志勇.射流力学[M].北京:科学出版社,2005.Dong Z Y.Jet Mechanics[M].Beijing:Science Press,2005.
[11]Fanger P O,Christensen N K.Perception of draught in ventilated spaces[J].Ergonomics,1986,29(2):215-235.
[12]Fanger P O,Melikov A K,Hanzawa H,et al.Air turbulence and sensation of draught[J].Energy&Buildings,1988,12(1):21-39.
[13]Torrence C,Compo G P.A practical guide to wavelet analysis[J].Bulletin of the American Meteorological Society,1998,79(1):61-78.
[14]Lee D T L,Yamamoto A.Wavelet analysis:theory and applications[J].Hewlett-Packard Journal,1994,45(6):44-54.
[15]姜楠,王振东.子波分析辨识壁湍流猝发事件的能量最大准则[J].力学学报,1997,29(4):406-411.Jiang N,Wang Z D.The maximum energy criterion for identifying burst events in wall turbulence using wavelet analysis[J].Acta Mechanica Sinica,1997,29(4):406-411.
[16]刘欣,姜楠.喷口加齿湍射流增强混合的实验与数值研究[J].航空动力学报,2006,21(5):884-890.Liu X,Jiang N.Experimental study over the passive control of turbulent jet flow with wedged nozzle[J].Journal of Aerospace Power,2006,21(5):884-890.
[17]舒玮,姜楠.湍流中涡的尺度分析[J].空气动力学学报,2000,18(S):89-95.Shu W,Jiang N.Eddy scale analysis in turbulence[J].Acta Aerodynamica Sinica,2000,18(S):89-95.
[2]Cao X,Liu J,Pei J,et al.2D-PIV measurement of aircraft cabin air distribution with a high spatial resolution[J].Building&Environment,2014,82(82):9-19.
[3]王维,姜楠,曹晓东,等.MD-82飞机客舱环境流场的HWA测量与分析[J].天津大学学报(自然科学与工程技术版),2013,46(1):2-7.Wang W,Jiang N,Cao X D,et al.HWA measurement and analysis of fluid field in MD-82aircraft cabin[J].Journal of Tianjin University(Natural Science and Engineering Technology),2013,46(1):2-7.
[4]Anderson M D.Effect of gaspers on airflow patterns and the transmission of airborne contaminants within an aircraft cabin environment[D].Kansas Satate University,2010.
[5]Liu W,Mazumdar S,Zhang Z,et al.State-of-the-art methods for studying air distributions in commercial airliner cabins[J].Building&Environment,2012,47:5-12.
[6]Li J,Liu J,Cao X,et al.Experimental study of transient air distribution of a jet collision region in an aircraft cabin mock-up[J].Energy&Buildings,2016,127:786-793.
[7]Zaman K B M Q.Control of an axisymmetric jet using vortex generators[J].Physics of Fluids,1994,6(2):778-793.
[8]刘欣.加小突片喷口射流增强混合的机理研究[D].天津:天津大学,2007.Liu X.A mechanism research about jet mixing enhancement by tabbed nozzle[D].Tianjin:Tianjin University,2007.
[9]张兆顺.湍流[M].北京:国防工业出版社,2002.Zhang Z S.Turbulence[M].Beijing:National Defence Industry Press,2002.
[10]董志勇.射流力学[M].北京:科学出版社,2005.Dong Z Y.Jet Mechanics[M].Beijing:Science Press,2005.
[11]Fanger P O,Christensen N K.Perception of draught in ventilated spaces[J].Ergonomics,1986,29(2):215-235.
[12]Fanger P O,Melikov A K,Hanzawa H,et al.Air turbulence and sensation of draught[J].Energy&Buildings,1988,12(1):21-39.
[13]Torrence C,Compo G P.A practical guide to wavelet analysis[J].Bulletin of the American Meteorological Society,1998,79(1):61-78.
[14]Lee D T L,Yamamoto A.Wavelet analysis:theory and applications[J].Hewlett-Packard Journal,1994,45(6):44-54.
[15]姜楠,王振东.子波分析辨识壁湍流猝发事件的能量最大准则[J].力学学报,1997,29(4):406-411.Jiang N,Wang Z D.The maximum energy criterion for identifying burst events in wall turbulence using wavelet analysis[J].Acta Mechanica Sinica,1997,29(4):406-411.
[16]刘欣,姜楠.喷口加齿湍射流增强混合的实验与数值研究[J].航空动力学报,2006,21(5):884-890.Liu X,Jiang N.Experimental study over the passive control of turbulent jet flow with wedged nozzle[J].Journal of Aerospace Power,2006,21(5):884-890.
[17]舒玮,姜楠.湍流中涡的尺度分析[J].空气动力学学报,2000,18(S):89-95.Shu W,Jiang N.Eddy scale analysis in turbulence[J].Acta Aerodynamica Sinica,2000,18(S):89-95.