The TTCF Method Of Boundary Slippage Critical Point Calculation

With the increasing development of nanotechnology and molecular dynamicssimulation technology，the research of fluid flow characteristics in nano-scale has greatpractical significance. Properties of fluid have been paid much attention. In the process ofmicro-and nano-scale fluid flow. Flowing velocity slippage has a very important influence.In classical fluid mechanics, no-slip boundary condition refers to the velocity of relativemotion between the fluid and the solid surfaces is zero. The so-called boundary slippagerefers to the phenomenon that fluid has a relative motion to the solid surface. with thedevelopment of micro and nano-testing technology and its related fields of science andtechnology boundary slippage is existed in many cases.In this paper, different parameters of boundary slippage phenomena due to the liquidflow on the solid-liquid interface have been studied extensively. The relationship betweendifferent parameters and boundary slippage is obtained, especially the relationship ofdifferent parameters with the critical point. In the micro and nano-scale, the critical pointis the state of between with and without boundary slippage. A state whitch is greater thanthe critical point is called a boundary slippage In this cases. on the contrary,a state isnon-slip boundary. Corresponding to the critical value of external force is called criticalforce. The method of TTCF has been conducted for nano-scale flows. the critical point andcritical force of the boundary slippage are identified. Influences of material parametersand Plus the driving force on the critical value of boundary slippage are analyzed.Through a comprehensive analysis of the calculation results, It is concluded that the manylaws of the boundary slip. Also found in the calculation process, TTCF method moreaccurately locate the boundary slip critical point and critical force compared withtraditional methods. The results of the study show Whether it is high-speed or low-speedflow of the flow, TTCF method more accurately locate the boundary slip critical point. Tosolve the traditional method can’t pinpoint the boundary slip point problem under thecondition of low speed flow.