带内凸肋板和外凹槽的通风管道内颗粒物的沉降规律研究（英文）
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摘要
本文采用数值模拟手段对带内凸肋板、外凹槽的通风管内颗粒物的沉降规律进行了研究。对于0.1～50μm粒径的颗粒物,采用修正的RSM和DPM模型能准确地模拟通风管道中颗粒物的沉降特性。与光滑管道相比可知,内凸、外凹槽通风管道中颗粒沉积速度(V_d~+)随弛豫时间(τ~+)或颗粒物粒径的增大而大幅度提高;更具体来讲,在τ~+<1的湍流扩散区和涡扩散碰撞区,V_d~+可以增强2～4个数量级并在τ~+≈0.3(d_p=2μm)时达到最大值,增设凸肋板和外凹槽能分别使颗粒物沉降能量增强7770和1320倍。在τ~+>1的惯性力区,颗粒物的运动主要受惯性力主导,V_d~+增幅较缓。总体而言,增设内凸、外凹槽可以强化颗粒物的沉积,且对小粒径颗粒物作用更显著,因此,这为减少PM2.5(d_(pm)<2.5μm)提供了一种好的选择。此外,相比于外凹槽,增设凸肋板的通风管道近壁区空气流动更加复杂,产生更高的湍动能,有利于颗粒物沉积,V_d~+增幅更大。然而,若考虑压力损失,带有外凹槽的通风管道虽然V_d~+相对较低,但效率更高。
A numerical study is carried out on particle deposition in ducts with either convex or concave wall cavity.Results show that,if compared with smooth duct,particle deposition velocities(V_d~+)increase greatly in ducts with wall cavities.More specifically,for τ~+<1,V_d~+ increase by about 2–4 orders of magnitude in the cases with the convex and concave wall cavities;for τ~+>1,V_d~+ grows relatively slower.Enhancement of particle deposition with wall cavities is caused by the following mechanisms,i.e.,interception by the wall cavities,expanded deposition area,and the enhanced flow turbulence.In general,addition of wall cavities is contributive for particle deposition,so it provides an efficient approach to remove particles,especially with small size,e.g.,PM2.5.Moreover,the convex wall cavity leads to a larger increment of V_d~+ than the concave wall cavity.However,taking pressure loss into account,though V_d~+ is relatively lower,duct with the concave wall cavity is more efficient than that with the convex wall cavity.
A numerical study is carried out on particle deposition in ducts with either convex or concave wall cavity.Results show that,if compared with smooth duct,particle deposition velocities(V_d~+)increase greatly in ducts with wall cavities.More specifically,for τ~+<1,V_d~+ increase by about 2–4 orders of magnitude in the cases with the convex and concave wall cavities;for τ~+>1,V_d~+ grows relatively slower.Enhancement of particle deposition with wall cavities is caused by the following mechanisms,i.e.,interception by the wall cavities,expanded deposition area,and the enhanced flow turbulence.In general,addition of wall cavities is contributive for particle deposition,so it provides an efficient approach to remove particles,especially with small size,e.g.,PM2.5.Moreover,the convex wall cavity leads to a larger increment of V_d~+ than the concave wall cavity.However,taking pressure loss into account,though V_d~+ is relatively lower,duct with the concave wall cavity is more efficient than that with the convex wall cavity.
引文
[1]POPE C A,BURNETT R T,THUN M J,CALLE E E,KREWSKI D,ITO K,THURSTON G D.Lung cancer,cardiopulmonary mortality,and long-term exposure to fine particulate air pollution[J].Journal American Medical Association,2002,287:1132-1141.
[2]LAI A C K.Particle deposition indoors:A review[J].Indoor Air,2002,12:211-214.
[3]BOUILLY J,LIMAM K,BéGHEIN C,ALLARD F.Effect of ventilation strategies on particle decay rates indoors:An experimental and modelling study[J].Atmospheric Environment,2005,39:4885-4892.
[4]LAI A C K,BYRNE M A,GODDARD A J H.Measured deposition of aerosol particles on a two-dimensional ribbed surface in a turbulent duct flow[J].Journal of Aerosol Science,1999,30:1201-1214.
[5]LAI A C K,BYRNE M A,GODDARD A J H.Enhanced particle loss in ventilation duct with ribbed surface[J].Building and Environment,2000,35:425-432.
[6]BARTH T,REICHE M,BANOWSKI M,OPPERMANN M,HAMPEL U.Experimental investigation of multilayer particle deposition and resuspension between periodic steps in turbulent flows[J].Journal of Aerosol Science,2013,64:111-124.
[7]SIPPOLA M R,NAZAROFF W W.Experiments measuring particle deposition from fully developed turbulent flow in ventilation ducts[J].Aerosol Science Technology,2004,38(9):914-925.
[8]BAGHDAR HOSSEINI S,HAGHIGHI KHOSHKHOO R,MALABAD S M.Experimental and numerical investigation on particle deposition in a compact heat exchanger[J].Applied Thermal Engineering,2017,115(25):406-417.
[9]ZHANG H,GOODARZL A.Aerosol particle transport and deposition in vertical and horizontal turbulent duct flows[J].Journal Fluid Mechanics,2000,406:55-80.
[10]MATIDA E A,FINLAY W H,LANGE C F,GRGIC B.Improved numerical simulation of aerosol deposition in an idealized mouth-throat[J].Journal of Aerosol Science,2004,35(1):1-19.
[11]BEGHEIN C,JIANG Y,CHEN Q Y.Using large eddy simulation to study particle motions in a room[J].Indoor Air,2005,15(4):281-290.
[12]DRITSELIS C D.Numerical study of particle deposition in a turbulent channel flow with transverse roughness elements on one wall[J].International Journal Multiphase Flow,2017,91:1-18.
[13]LO IACONO G,TUCKER P G,REYNOLDS A M.Predictions for particle deposition from LES of ribbed channel flow[J].International Journal Heat Fluid Flow,2005,26(4):558-568.
[14]WANG Y.On the effect of anisotropy on the turbulent dispersion and deposition of small particles[J].International Journal Multiphas Flow,1999,25:551-558.
[15]ZHANG Z,CHEN Q.Comparison of the Eulerian and Lagrangian methods for predicting particle transport in enclosed spaces[J].Atmospheric Environment,2007,41:5236-5248.
[16]ZHANG Z,CHEN Q.Prediction of particle deposition onto indoor surfaces by CFD with a modified Lagrangian method[J].Atmospheric Environment,2009,43(2):319-328.
[17]HE C,AHMADI G.Particle deposition in a nearly developed turbulent duct flow with electrophoresis[J].Journal of Aerosol Science,1999,30(6):739-758.
[18]MEHEL A,TANIèRE A,OESTERLéB,FONTAINE J R.The influence of an anisotropic Lagrangian dispersion model on the prediction of micro-and nano-particle deposition in wall-bounded turbulent flows[J].Journal of Aerosol Science,2010,41(8):729-744.
[19]TIAN L,AHMADI G.Particle deposition in turbulent duct flows-comparisons of different model predictions[J].Journal of Aerosol Science,2007,38:377-397.
[20]ZHANG J,LI A.CFD simulation of particle deposition in a horizontal turbulent duct flow[J].Chemical Engineering Research Design,2008,86(1):95-106.
[21]PARKER S,FOAT T,PRESTON S.Towards quantitative prediction of aerosol deposition from turbulent flows[J].Journal of Aerosol Science,2008,39(2):99-112.
[22]GAO N,NIU J,HE Q,ZHU T,WU J.Using RANSturbulence models and Lagrangian approach to predict particle deposition in turbulent channel flows[J].Building Environment,2012,48:206-214.
[23]LECRIVAIN G,SEVAN D M,THOMAS B,HAMPEL U.Numerical simulation of multilayer deposition in an obstructed channel flow[J].Advance Powder Technology,2014,25(1):310-320.
[24]LU H,LU L.Numerical investigation on particle deposition enhancement in duct air flow by ribbed wall[J].Building Environment,2015,85:61-72.
[25]LU H,LU L.A numerical study of particle deposition in ribbed duct flow with different rib shapes[J].Building Environment,2015,94:43-53.
[26]LU H,LU L.Effects of rib spacing and height on particle deposition in ribbed duct air flows[J].Building Environment,2015,92:317-327.
[27]LU H,LU L.CFD investigation on particle deposition in aligned and staggered ribbed duct air flows[J].Applied Thermal Engineering,2016,93:697-706.
[28]WANG F,ZHANG E,WANG J.A study of particle deposition in ventilation ducts with convex or con-cave wall cavity[J].Procedia Engineering,2017,205:3285-3292.
[29]RAN J,LI L,DU X,WANG R,PAN W.Numerical investigations on characteristics of methane catalytic combustion in micro-channels with a concave or convex wall cavity[J].Energy Conversion Management,2015,97:188-195.
[30]ANSARIPOUR M,ABDOLZADEH M,SARGAZIZADEHS.Computational modeling of particle transport and distribution emitted from a laserjet printer in a ventilated room with different ventilation configurations[J].Applied Thermal Engineering,2016,103:920-933.
[31]ZHOU J,ZHANG J.Numerical investigation of particle deposition on converging slot-hole film-cooled wall[J].Journal of Central South University,2017,24(12):2819-2828.
[32]FLUENT Inc.FLUENT 14.0 user's guide[M].Lebanon,NH,2011.
[33]KIM J,MOIN P,MOSER R.Turbulence statistics in fully developed channel flow at low Reynolds number[J].Journal Fluid Mechanics,1987,177:133-166.
[34]KVASNAK W,AHMADI G,BAYER R,GAYNES M.Experimental investigation of dust particle deposition in a turbulent channel flow[J].Journal of Aerosol Science,1993,24(6):795-815.
[35]SEHMEL G A.Particle resuspension from an asphalt road caused by car and truck traffic[J].Atmospheric Environment,1973,7(3):291-309.
[36]WOOD N B.A simple method for the calculation of turbulent deposition to smooth and rough surfaces[J].JAerosol Sci,1981,12:275-290.
[37]MONTGOMERY T L,CORN M.Aerosol deposition in a pipe with turbulent airflow[J].Journal of Aerosol Science,1970,1(3):185-194.
[38]SEHMEL G A.Aerosol deposition from turbulent airstreams in vertical conduits[R].Richland,Washington:Battelle Northwest Lab,BNWL-578,1968.
[39]LEE A,AHMADI G,BAYER R G,GAYNES M A.Aerosol particle deposition in an obstructed turbulent duct flow[J].JAerosol Sci,1994,25:91-112.
[40]LIU B Y H,AGARWAL J K.Experimental observation of aerosol deposition in turbulent flow[J].J Aerosol Sci,1974,5:145-155.
[41]WELLS A C,CHAMBERLAIN A C.Transport of small particles to vertical surfaces[J].British Journal of Applied Physics,1967,18:1793-1799.
[42]FRIEDLANDER S K,JOHNSTONE H E.Deposition of suspended particles from turbulent gas streams[J].Industrial and Engineering Chemistry,1957,49:1151-1156.
[43]POSTMA A K,SCHWENDIMAN L C.Studies in micrometrics:Particle deposition in conduits as a source of error in aerosol sampling[R].Richland,Washington:Hanford Lab,HW-65308,1960.
[2]LAI A C K.Particle deposition indoors:A review[J].Indoor Air,2002,12:211-214.
[3]BOUILLY J,LIMAM K,BéGHEIN C,ALLARD F.Effect of ventilation strategies on particle decay rates indoors:An experimental and modelling study[J].Atmospheric Environment,2005,39:4885-4892.
[4]LAI A C K,BYRNE M A,GODDARD A J H.Measured deposition of aerosol particles on a two-dimensional ribbed surface in a turbulent duct flow[J].Journal of Aerosol Science,1999,30:1201-1214.
[5]LAI A C K,BYRNE M A,GODDARD A J H.Enhanced particle loss in ventilation duct with ribbed surface[J].Building and Environment,2000,35:425-432.
[6]BARTH T,REICHE M,BANOWSKI M,OPPERMANN M,HAMPEL U.Experimental investigation of multilayer particle deposition and resuspension between periodic steps in turbulent flows[J].Journal of Aerosol Science,2013,64:111-124.
[7]SIPPOLA M R,NAZAROFF W W.Experiments measuring particle deposition from fully developed turbulent flow in ventilation ducts[J].Aerosol Science Technology,2004,38(9):914-925.
[8]BAGHDAR HOSSEINI S,HAGHIGHI KHOSHKHOO R,MALABAD S M.Experimental and numerical investigation on particle deposition in a compact heat exchanger[J].Applied Thermal Engineering,2017,115(25):406-417.
[9]ZHANG H,GOODARZL A.Aerosol particle transport and deposition in vertical and horizontal turbulent duct flows[J].Journal Fluid Mechanics,2000,406:55-80.
[10]MATIDA E A,FINLAY W H,LANGE C F,GRGIC B.Improved numerical simulation of aerosol deposition in an idealized mouth-throat[J].Journal of Aerosol Science,2004,35(1):1-19.
[11]BEGHEIN C,JIANG Y,CHEN Q Y.Using large eddy simulation to study particle motions in a room[J].Indoor Air,2005,15(4):281-290.
[12]DRITSELIS C D.Numerical study of particle deposition in a turbulent channel flow with transverse roughness elements on one wall[J].International Journal Multiphase Flow,2017,91:1-18.
[13]LO IACONO G,TUCKER P G,REYNOLDS A M.Predictions for particle deposition from LES of ribbed channel flow[J].International Journal Heat Fluid Flow,2005,26(4):558-568.
[14]WANG Y.On the effect of anisotropy on the turbulent dispersion and deposition of small particles[J].International Journal Multiphas Flow,1999,25:551-558.
[15]ZHANG Z,CHEN Q.Comparison of the Eulerian and Lagrangian methods for predicting particle transport in enclosed spaces[J].Atmospheric Environment,2007,41:5236-5248.
[16]ZHANG Z,CHEN Q.Prediction of particle deposition onto indoor surfaces by CFD with a modified Lagrangian method[J].Atmospheric Environment,2009,43(2):319-328.
[17]HE C,AHMADI G.Particle deposition in a nearly developed turbulent duct flow with electrophoresis[J].Journal of Aerosol Science,1999,30(6):739-758.
[18]MEHEL A,TANIèRE A,OESTERLéB,FONTAINE J R.The influence of an anisotropic Lagrangian dispersion model on the prediction of micro-and nano-particle deposition in wall-bounded turbulent flows[J].Journal of Aerosol Science,2010,41(8):729-744.
[19]TIAN L,AHMADI G.Particle deposition in turbulent duct flows-comparisons of different model predictions[J].Journal of Aerosol Science,2007,38:377-397.
[20]ZHANG J,LI A.CFD simulation of particle deposition in a horizontal turbulent duct flow[J].Chemical Engineering Research Design,2008,86(1):95-106.
[21]PARKER S,FOAT T,PRESTON S.Towards quantitative prediction of aerosol deposition from turbulent flows[J].Journal of Aerosol Science,2008,39(2):99-112.
[22]GAO N,NIU J,HE Q,ZHU T,WU J.Using RANSturbulence models and Lagrangian approach to predict particle deposition in turbulent channel flows[J].Building Environment,2012,48:206-214.
[23]LECRIVAIN G,SEVAN D M,THOMAS B,HAMPEL U.Numerical simulation of multilayer deposition in an obstructed channel flow[J].Advance Powder Technology,2014,25(1):310-320.
[24]LU H,LU L.Numerical investigation on particle deposition enhancement in duct air flow by ribbed wall[J].Building Environment,2015,85:61-72.
[25]LU H,LU L.A numerical study of particle deposition in ribbed duct flow with different rib shapes[J].Building Environment,2015,94:43-53.
[26]LU H,LU L.Effects of rib spacing and height on particle deposition in ribbed duct air flows[J].Building Environment,2015,92:317-327.
[27]LU H,LU L.CFD investigation on particle deposition in aligned and staggered ribbed duct air flows[J].Applied Thermal Engineering,2016,93:697-706.
[28]WANG F,ZHANG E,WANG J.A study of particle deposition in ventilation ducts with convex or con-cave wall cavity[J].Procedia Engineering,2017,205:3285-3292.
[29]RAN J,LI L,DU X,WANG R,PAN W.Numerical investigations on characteristics of methane catalytic combustion in micro-channels with a concave or convex wall cavity[J].Energy Conversion Management,2015,97:188-195.
[30]ANSARIPOUR M,ABDOLZADEH M,SARGAZIZADEHS.Computational modeling of particle transport and distribution emitted from a laserjet printer in a ventilated room with different ventilation configurations[J].Applied Thermal Engineering,2016,103:920-933.
[31]ZHOU J,ZHANG J.Numerical investigation of particle deposition on converging slot-hole film-cooled wall[J].Journal of Central South University,2017,24(12):2819-2828.
[32]FLUENT Inc.FLUENT 14.0 user's guide[M].Lebanon,NH,2011.
[33]KIM J,MOIN P,MOSER R.Turbulence statistics in fully developed channel flow at low Reynolds number[J].Journal Fluid Mechanics,1987,177:133-166.
[34]KVASNAK W,AHMADI G,BAYER R,GAYNES M.Experimental investigation of dust particle deposition in a turbulent channel flow[J].Journal of Aerosol Science,1993,24(6):795-815.
[35]SEHMEL G A.Particle resuspension from an asphalt road caused by car and truck traffic[J].Atmospheric Environment,1973,7(3):291-309.
[36]WOOD N B.A simple method for the calculation of turbulent deposition to smooth and rough surfaces[J].JAerosol Sci,1981,12:275-290.
[37]MONTGOMERY T L,CORN M.Aerosol deposition in a pipe with turbulent airflow[J].Journal of Aerosol Science,1970,1(3):185-194.
[38]SEHMEL G A.Aerosol deposition from turbulent airstreams in vertical conduits[R].Richland,Washington:Battelle Northwest Lab,BNWL-578,1968.
[39]LEE A,AHMADI G,BAYER R G,GAYNES M A.Aerosol particle deposition in an obstructed turbulent duct flow[J].JAerosol Sci,1994,25:91-112.
[40]LIU B Y H,AGARWAL J K.Experimental observation of aerosol deposition in turbulent flow[J].J Aerosol Sci,1974,5:145-155.
[41]WELLS A C,CHAMBERLAIN A C.Transport of small particles to vertical surfaces[J].British Journal of Applied Physics,1967,18:1793-1799.
[42]FRIEDLANDER S K,JOHNSTONE H E.Deposition of suspended particles from turbulent gas streams[J].Industrial and Engineering Chemistry,1957,49:1151-1156.
[43]POSTMA A K,SCHWENDIMAN L C.Studies in micrometrics:Particle deposition in conduits as a source of error in aerosol sampling[R].Richland,Washington:Hanford Lab,HW-65308,1960.