Hybrid Methods for Computing the Streamfunction and Velocity Potential for Complex Flow Fields over Mesoscale Domains

作     者：Jie CAO Qin XU Haishan CHEN Shuping MA Jie CAO;Qin XU;Haishan CHEN;Shuping MA

作者机构：Key Laboratory of Meteorological Disaster(KLME)Ministry of Education&Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044China Cooperative Institute for Mesoscale Meteorological Studies(CIMMS)University of OklahomaNorman 73072OklahomaUSA NOAA/OAR/National Severe Storms LaboratoryNorman 73069OklahomaUSA Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2022年第39卷第9期

页      面：1417-1431页

核心收录：

学科分类：07[理学] 0706[理学-大气科学] 

基　　金：supported by the National Natural Science Foundation of China under Grant Nos. 91937301, 41875074, and 41675060 the Second Tibetan Plateau Comprehensive Scientific Expedition 2019QZKK0104 the National Key Scientific and Technological Infrastructure Project “EarthLab” provided by NOAA/OAR under NOAA–OU Cooperative Agreement #NA16OAR4320072, U.S. Department of Commerce 

主　　题：streamfunction and velocity potential complex flow fields successive over-relaxation method mesoscale study 

摘      要：Three types of previously used numerical methods are revisited for computing the streamfunctionψand velocity potentialχfrom the horizontal velocity v in limited domains.The first type,called the SOR-based method,uses a classical successive over-relaxation(SOR)scheme to computeψ(orχ)first with an arbitrary boundary condition(BC)and thenχ(orψ)with the BC derived from v.The second type,called the spectral method,uses spectral formulations to construct the inner part of(ψ,χ)-the inversion of(vorticity,divergence)with a homogeneous BC,and then the remaining harmonic part of(ψ,χ)with BCs from v.The third type,called the integral method,uses integral formulas to compute the internally induced(ψ,χ)-the inversion of domain-internal(vorticity,divergence)using the free-space Greenꞌs function without BCs and then the remaining harmonicψ(orχ)with BCs from v minus the internally-induced part.Although these methods have previously been successfully applied to flows in large-scale and synoptic-scale domains,their accuracy is compromised when applied to complex flows over mesoscale domains,as shown in this paper.To resolve this problem,two hybrid approaches,the integral-SOR method and the integral-spectral method,are developed by combining the first step of the integral method with the second step adopted from the SOR-based and spectral methods,respectively.Upon testing these methods on real-case complex flows,the integral-SOR method is significantly more accurate than the integral-spectral method,noting that the latter is still generally more accurate than the three previously-used methods.The integral-SOR method is recommended for future applications and diagnostic studies of complex flows.