A TVD SCHEME FOR INCOMPRESSIBLE FLOW COUPLED WITH DIFFERENT TURBULENCE MODLES ON A GROUND- MOUNTED SQUARE-RIB FLOW

A finite-difference Total Variation Diminishing (TVD) numerical simulation model for coupling the Reynolds Averaged Navier-Stokes (RANS) equations, pressure-relative continuity equation and various k-εturbulence models was developed to solve the incompressible flow based on the pseudo-compressibility method. The hyperbolicity of all these equations was studied and the discretization of the fully coupling equations with all the primal variables and source terms were made in this article. Numerical simulation for modeling the flow around a ground-mounted square rib was implemented and validated by comparing with the published wind tunnel experimental data. It is shown that such a numerical simulation method with a proper turbulence model has a very good accuracy to simulate the flow around a surface-mounted rib. It is concluded that the Renormalization Group (RNG) and Chen-Kim k-εturbulence models have much better ability to predict the characteristics of the vortex structure and flow separation than the standard k-εmodel.     

MMSE channel estimation for two-port demodulation reference signals in new radio

Dear editor, Orthogonal frequency division multiplexing (OFDM) has been adopted in new radio (NR)[1],and multiple-port de-modulation reference signal (DMRS) has...     

OPTIMIZING LAYOUT OF URBAN STREET CANYON USING NUMERICAL SIMULATION COUPLING WITH MATHEMATICAL OPTIMIZATION

1. INTRODUCTION Vehicular emissions have become one of thmain sources of urban atmospheric pollution in Chinwith the development of the urban construction andthe increase in the number of vehicles. There are lots of factors influencing the transport and dispersion of vehicular exhausted pollutants and further influencing the local air quality, among which the gas dynamical effect due to the mechanical turbulence from huge buildings and street canyons is especially remarkable. Previous stu…     

Release Behavior of Sulfur during Fluidized Bed Gasification

During fluidized bed gasification,sulfur in coal will be released,which will lead to environmental pollution.The release behavior of sulfur in fluidized bed gas...     

Direct Ink Writing of Highly Conductive MXene Frames for Tunable Electromagnetic Interference Shielding and Electromagnetic Wave?Induced Thermochromism

The highly integrated and miniaturized next-generation electronic products call for high-performance electromagnetic interfer?ence (EMI) shielding materials to ...     

氯化钾结晶器搅拌选型探研

反浮选冷结晶氯化钾生产的关键在于DTB结晶器中的控速分解和控速结晶,而控速的关键在于搅拌器的调速,因此本文通过对搅拌工作原理、类型及机理的粗浅分析,在保证不影响分解和结晶速率的情况下选用合适的搅拌型式,生产实践证明:推进式轴流型搅拌较之折叶式径漉型搅拌在提高氯化钾产品的粒度方面有极大的优越性.     

Twinning, dynamic recovery and recrystallization in the hot rolling process of twin-roll cast AZ31B alloy

Hot-rolling experiments with a reduction from 10% to 60% in single pass were conducted on AZ31B twin-roll cast sheets. Optical microscope (OM), electron backscattered diffraction (EBSD) tests and transmission electron microscope (TEM) were used to investigate twinning and DRV/DRX behaviors at different stage in the hot-rolling process. Two types of twinning occurred in the initial stage of hot-rolling process. DRV and discontinuous recrystallization dominated at moderate strain while continuous DRX took place homogeneously throughout original grains at the largest strains.     

浅析辽代农业科学发展状况

辽代农业科学技术在原有的基础上已取得了进一步发展,尤其是在生产工具和耕作技术等方面都取得了长足的进步,为辽代农业的繁荣创造了有利条件.     

转喻在古汉字造字表词方法中的运用例说——整体的部分与部分之间的转喻

认知语言学有关转喻的理论可用来分析古汉字造字表词的方法,由此得出了整体的部分与部分之间转喻的几种形式,如工具转喻法、因果转喻法、容纳转喻法等.从认知角度探索古汉字造字表词的方法,可以从宏观上了解先人的造字思维,把握古文字的造字规律,为古汉字的释读提供新鲜的也许是更为科学的思路.