Applied Mechanics and Materials Vols. 477-478

Abstract: Multi-layers parallel plates perfusion bioreactor has the potential advantage in cells cultivation of tissue engineering and good scalability for cells cultivation on a large scale. It is necessary to analyze the distribution of flow shear stress (FSS) of bioreactors which has strong influence on the growth of cells. The result of meshing was not satisfactory because of the complexity of multi-layers parallel plates when using computational fluid dynamics (CFD) to analyze the FSS, and the amount of calculation was great and complex especially under the process of influence on FSS caused by analyzing the different structure. The new method of simplified flow field analysis was presented in this paper, which was based on relation between FSS and flow and made the process simpler by analyzing distribution of rate instead of FSS. The simulation result showed that this method can satisfy the requirement of precision and provide reference for the analysis of the flow field which had the established relationship between structural parameters and laminar flow within it.

Abstract: A 2D model of a blood vessel under rolling manipulation (RM) is presented. The numerical simulations of blood flow are based on lattice Boltzmann method. It is found that RM can increase the blood flow. Different RM frequency () has different influence on flow. When the frequency is equal to the pulsing flow frequency,the average flow over one period is the largest. Streamlines diagrams in different time when are given. Vortexes can be seen in the region under the stenosis. The distributions of streamlines change periodically.

Abstract: Analyze veracity and computing efficiency of direct route drag of axis symmetry revolution body with 2D Computer Fluid Dynamic (CFD) method by comparing to the experiment data, discuss affection of different wall boundary functions to the results when calculating Automatic Underwater Vehicles (AUVs) hydrodynamic performance in CFD method. Find out characters of several meshing strategies when spring-based smooth dynamic model is adopted. Method with ball domain inside, which can simulate all the PMM tests and get reasonable outcome, turned out to be the best choice.

Abstract: A direct numerical simulation (DNS) of three-dimensional turbulent Rayleigh-Bénard (RB) convection is investigated. An efficient and accurate method to solve pressure Poisson equation in RB convection is presented by fast Fourier transform (FFT) and a high-performance solution of five-diagonal matrix. The three-dimensional turbulent RB convection in a narrow rectangular cell is studied. The motions and characteristics of plumes and large-scale circulation are analyzed.

Abstract: BR0.3 type plate heat exchanger was used for the experiment. Through the test platform of plate heat exchanger, a large number of experiments have been done in different mixed mode but the same passageway. By the linear fitting method and the analysis of the data, the formula of flow resistance which fit at any mixed mode is obtained, it solves the problem of calculating flow resistance and has a great help for engineering calculation.

Abstract: A pulsatile circulation system has been built to simulate aortic blood flow. The system has both upstream and downstream compliances and resistances to simulate the elasticity and resistances of blood circulation system. Influences of the compliances and resistances on the pulsatile pressure waveforms have been systematically studied using this system. We found that in absence of the compliances and the downstream resistance, it results in an oversize negative pulsation to the pressure waveforms. The downstream resistance hardly affects the structure of the pressure waveforms, whereas the mean amplitude of pressure increases along with the downstream resistance. The compliance can reduce the peak value of the pressure, which is unrelated to the location of the compliance but related to the elasticity in the system. With fixed upstream system elasticity, the pressure waveform is more stable.

Abstract: Used FLUENT software to simulate the flow distribution of a certain horizontal turbine with its blade angle changed from 25 ° to-35 °.The simulation results show the flow field changes with a period which was a fifth to the turbine rotational period. When the blade heads deflected laterally, the high flow velocity appeared near rear back turbine blades, or it appeared near the facing flow blades which were in the front lower part of the turbine. Besides, for blade angle deflected inside models, a stable annular velocity vector vortex gradually emerged around turbine as blade angle increased. The maximum velocity of flow field increased firstly and then stayed stable as blade angle changed. The flow distribution results fully confirmed that the reasonable optimization to the blade angle of the turbine can help the turbine achieve a more effective rotation and improve the flow distribution.

Abstract: Analyzed the research status of flotation separation in the field of water treatment. By using CFD software, the important parameters of velocity and pressure in the flotation column are analyzed and contrasted. Through the simulation, it will identify design adequacy and optimize operating parameters and structural parameters. The important factors influencing floatation column separation are got. In the process of oil-water separation, keeping proper bubble size and gas holdup is necessary.

Abstract: Two-dimensional models of inclined flat and corrugated walls are established based on VOF method to numerically simulate the flow characteristics of liquid film. The impact of wall structures on the wave profile of the film is studied. The results indicate that the wall structure plays an important role on the liquid film, there are vortexes generated on the trough of wavy wall, the vortex has the "rolling" effect in machinery, which reduces the viscous resistance. and continuous film is easier to form on the wall whose corrugated size is smaller.

Abstract: A high-speed craft in the supersonic speed, ambient temperature and pressure would affect its structure, heat flow fluid-solid coupling simulation can quantify the effect. Due to physical fields had different heat flow fluid-solid coupling simulation, the data transmission was needed when the fluid dynamics to calculate the quantities of the import structure field. This paper given the derivation process and method of the physical fields data transfer, fluid dynamics to calculate the data in the simulation of structure field was implemented and to quantify the temperature field and stress field impacted on structure field.