Structure and coupling characteristics of multiple fields in dust storms
Dust storms are typical dispersed two-phase atmospheric turbulence,where dust particles are highly charged.Although the very-large-scale motions(VLSMs)have been recognized in single-phase high-Reynolds-number turbulence,they remain largely unexplored in dust storms,especially regarding turbulent electric fields.Here,using datasets from field measurements in the atmospheric surface layer,we demonstrate that VLSMs of approximately the same size are found to exist in wind velocity,con-centration of dust particles less than 10 micrometers in diameter(PM10 dust concentration),and electric fields in dust storms.Furthermore,such multiple fields are found to be maximally linearly coupled at the scale of the VLSMs,with linear coherence spectra in the range of 0.5-0.8.By performing transfer entropy analysis,we further demonstrate that wind velocity and PM 10 dust concentration are maximally nonlinearly coupled at wavenumber k1=0.002 m-1,whereas PM10 dust concentration and electric field are maximally nonlinearly coupled at k1=0.15 m-1,suggesting different nonlinear coupling behaviours between the wind-dust and dust-electrostatics interactions.Our results shed light on the structural and coupling features of the multiple fields in dust storms and thus deliver key information for understanding complex dispersed two-phase turbulent flows.
Center for Particle-laden Turbulence,Lanzhou University,Lanzhou 730000,China
Key Laboratory of Mechanics on Disaster and Environment in Western China Attached to the Ministry of Education of China,Lanzhou University,Lanzhou 730000,China
Department of Mechanics and Engineering Science,College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China
Very-large-scale motions Electric fields Particle-laden flow Dust storms
National Natural Science Foundation of ChinaFundamental Research Funds for the Central Universities
NETL
NSTL
万方数据
