检索结果-南通市图书馆

Modelling of pressure-strain correlations for Taylor-Proudman turbulence

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 1998年第6期41卷 638-646页

作者：符松 Department of Engineering Mechanics Tsinghua University Beijing China

The theoretical foundation for the modelling of the turbulent pressure\|strain correlations in rotating reference frame is presented. Based on the recently developed materially\|frame indifference principle it is observed that most of the existing second\|moment closures violate the Taylor\|Proudman theorem in the limit of rapid rotation. It is shown that the application of the materially\|frame indifference principle gives rise to the formation of a new pressure\|strain correlation model which satisfies the Taylor\|Proudman theorem.

关键词： second\|moment closure rotating flows pressure\|strain correlations non\|inertial frame Taylor\|Proud man theorem.

Experimental observation of the nano-scale particles in geogas matters and its geological significance

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 1998年第3期41卷 325-329页

作者：童纯菡李巨初葛良全杨凤根 Chengdu University of Technology Chengdu China

The geogas collectors showing a geogas anomaly in field geogas prospecting and in simulation tests were selected for the observation under high resolution microscopy. The result demonstrates that the geogas matter is transported in the form of nano-scale particles with a size of aboutN nm to N-10 nm, and accumulated into aggregations of 1-2 μm to N.10 μm, with globular and film shape, and the component of Cu, Zn, Cr, Au, Al, V, Si, Br, C1, S, Ca, etc. Based on the knowledge of nano science and technique, the mechanism of the geogas prospecting and its significance in geology and mineral prospecting are discussed.

关键词： geogas nano scale particles shape component ascending gas flows crust nano geology.

Numerical simulations of leading-edge vortex core axial velocity for flow over delta wings

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第7期52卷 2029-2036页

作者： CHEN Lan1, 2 & WANG JinJun1 1 Institute of Fluid Mechanics, Beijing University of Aeronautics and Astronautics, Beijing 100191, China 2 China Aerodynamic Research and Development Center (CARDC), Mianyang 621000, China Institute of Fluid Mechanics Beijing University of Aeronautics and Astronautics Beijing China China Aerodynamic Research and Development Center (CARDC) Mianyang China

Numerical simulations have been performed to investigate the characteristics of leading-edge vortex core axial velocity over two delta wings with leading edge swept angles Λ =50°and 76°, respectively. It is obtained that Reynolds number has the most important effect on the axial velocity of the primary leading-edge vortex core. At Reynolds numbers larger than 105, the jet-like flow of the vortex core is the most common type for both the large and the moderate swept delta wings. While if Reynolds number decreases to 103―104, the core axial velocity distributions for these two delta wings present the wake-like profile for all angles of attack considered in the present investigation.

关键词： delta wing low Reynolds number vortex flows

Influence of rheological parameters in all drag reduction regimes of turbulent channel flow with polymer additives

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2008年第S1期15卷 275-279页

作者：李昌烽赵作广吴桂芬冯晓东 School of Energy and Power Engineering Jiangsu University

The influence of rheological parameters on vortex dynamics and the extent of drag reduction (DR) were deciphered via extensively analyzing the hi-fidelity direct numerical simulation results of the turbulent channel flow with polymer solutions. It has been observed that in all drag reduction regimes from the onset of DR to maximum drag reduction (MDR) limit, the Deborah number is defined as the product of an effective Weissenberg number, and the root mean square streamwise vorticity fluctuation remains O(1) in the near wall region. The ratio of the average lifetime of axial vortices to the vortex rotating duration decreases with increasing DR, and MDR is achieved when these time scales become nearly equal. Based on these observations a simple framework is proposed adequately to describe the influence of polymer additives on the extent of DR from onset to MDR as well as the universality of the MDR in flow systems with polymer additives.

关键词： drag reduction dilute polymeric solutions turbulent channel flows FENE-P model

The Construction of Shanghai Pilot Free Trade Zone and the Interest Rate Liberalization in China

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2016年第2期21卷 234-246页

作者：罗素梅周光友 School of Finance Shanghai University of Finance and Economics Institute for Financial Studies Fudan University

It is of practical significance to study how to fully play the promoting effect of Shanghai Free Trade Zone(SFTZ) on China's marketization of interest rate after setting up SFTZ. In terms of interest parity theory,this article tries to divide the process of China's marketization of interest rate into different stages and conduct in-depth study of the formation mechanism of interest rate of each stage from the perspective of capital flow. The results show that marketization of interest rate is a system project. It can be divided into three stages: official interest rate supplemented market, two-track system and integration, according to the progress of marketization of interest rate, and the formation mechanism of interest rate of each stage varies. Free trade zone is a domestic and international hub for capital flow. The condition of capital flow influences capital supply, thus affecting the formation mechanism of interest rate domestically in free trade zone and promoting the progress of China's marketization of interest rate. Marketization of interest rate, capital account liberalization, internationalization of RMB, and construction of international financial center are the supplementary, inseparable and transitional process. Therefore, the promoting effect of SFTZ on the marketization of interest rate, the capital account liberalization, the internationalization of RMB and the construction of international financial center should be made full use of. Finally, on the basis of it, this study explores hardships that China's marketization of interest rate faces after the foundation of SFTZ and puts forward corresponding policy suggestion.

关键词： Shanghai Free Trade Zone(SFTZ) interest rate marketization capital flows interest rate parity

The inverse maximum dynamic flow problem

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2010年第10期53卷 2709-2717页

作者： BAGHERIAN Mehri Faculty of Electronics and Electrical Engineering Malek Ashtar University of Technology

We consider the inverse maximum dynamic flow (IMDF) *** problem can be described as: how to change the capacity vector of a dynamic network as little as possible so that a given feasible dynamic flow becomes a maximum dynamic *** discussing some characteristics of this problem,it is converted to a constrained minimum dynamic cut *** an efficient algorithm which uses two maximum dynamic flow algorithms is proposed to solve the problem.

关键词： network flows inverse optimization dynamic network flows

How does the rarefaction of the air affect hypersonic vehicles

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2021年第1期37卷 18-19,I0002页

作者： Youda Ye National Laboratory for Computational Fluid Dynamics Beijing100086China

The scope,physical concept,and mathematical model for describing how the rarefaction of the air affects on hypersonic flows have been discussed.A new method,namely the data improved Naive-Stroke(DiNS)model,was proposed for the computation of hypersonic shear flows around vehicles flying at altitude of 30-100 *** of the new continuum method has also been done.

关键词： hypersonic flows rarefaction

PREDICTION OF CONFINED TURBULENT GAS-PARTICLE JETS BY AN ENERGY EQUATION MODEL OF PARTICLE TURBULENCE

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 1990年第1期33卷 52-59页

作者：周力行黄晓晴 Tsinghua Uuiversity

Based on a kinetic energy equation of particle turbulence, a k-ε-kk model for turbulent gas-particle flows is proposed. The prediction of confined plane gas-particle jets shows a good agreement with experimental data. This model is proved to be far superior to the presently used k-ε-A.P. model based on the algebraic model of particle turbulence.

关键词： turbulent gas-particle flows particle turbulence transport.

The Impact of the US Interest Rate Hike on Emerging Market Economies and the Belt and Road Initiative

在线全文

学校读者我要写书评

暂无评论

China & World Economy 2019年第3期27卷 126-142页

作者： Shuyu Wu Biliang Hu Qingzhong Pan Emerging Markets Institute Beijing Normal University China

Since the end of 2015,the US Federal Reserve has raised its benchmark interest rate nine *** has led to capital outflows and asset depreciation in many emerging market *** present paper examines the factors that determine the financial volatility of emerging markets in the face of external *** calculating the capital flows of 30 emerging markets from 1990 to 2018 and conducting panel regression,this paper finds that countries with good infrastructure facilities,a sound banking system and high economic growth have significantly lower cross-border financial *** implication from the empirical analysis is that emerging countries would benefit greatly by actively taking part in the Belt and Road *** framework of the Belt and Road Initiative allows emerging countries better access to China s massive consumer market to promote trade and long-term *** quality of infrastructure can be improved through cooperation with China in infrastructure *** can also jointly establish a cooperative financial framework to enhance regional financial *** strategies will reduce systematic financial risks and counteract the negative impacts of US interest rate hikes.

关键词： Belt and Road Initiative cross-border capital flows emerging market economies US interest rate hike