221 / 2019-08-30 10:40:18

Research and Optimization on Flow Performance for a Multi-channel Inflation System with Multi-chambers

Inflation quality; Inflation efficiency; Multi-chambers system; AMESim

计算流体力学、多场耦合、生物力学、动力学等 > 计算流体力学

The representative difficulties in the traditional air supply system with a constant pressure source, such as low control accuracy and slow inflation speed, can directly affect the efficiency and quality of inflation. However, when involving multi-channel in the system, the inflation quality, described as the max pressure difference among all the chambers in this system, will be sensitive to the parameters of import pipes, which increases the difficulties to better control the inflation process. In order to study those problems, we provide a specific-volume multi-channel inflation system with multi-chambers in this paper. Monitoring a certain chamber’s pressure during the inflation process, the vent value on this channel will be automatically opened and the intake valve will be automatically closed when the pressure reaches the preset pressure . If the pressure is lower than another preset pressure , the vent valve will be closed and the intake valve will be opened. Thus, the system can control the whole chambers’ pressure to be stable within a small range.

Firstly, we establish a concentrated parameter model for specific-volume multi-channel inflation system by utilizing the software AMEsim, which can stabilize the pressure of all chambers. Then, we design and employ an orthogonal experiment for our established simulation model to study the individual and combine effects of import-pipe parameters on flow characteristics with the constant import pressure, such as diameter, quantity and position of the import pipe. During every simulation, we shall extract the max pressure difference and the time duration required for the pressure to stabilize. Decreasing the max difference can improve the inflation quality and decreasing the time duration can improve the inflation efficiency. Finally, based on those simulation data, we develop the mathematical equations to analyze the relationship between the max difference, the time duration and the import-pipe parameters in our proposed model. They can guide us to predict the optimal parameters so that both the quality and efficiency of inflation can get better improved.

Results show that, 1) Increasing the quantity of import pipes will lead to the redistribution of mass flow rate, which can greatly decrease the max temperature and the max pressure difference in the chambers during the inflation process. However, it also requires us to rearrange the pipeline, which can increase the energy loss within the pipes. Thus, the total mass flow rate can be reduced and then the inflation efficiency will also decrease. 2) The position of import pipes can directly influence the max pressure difference. The pressure in the chambers with import pipe will increase at the fastest rate. The farther away from the intake chamber, the lower the rate of increase in pressure will be. 3) The pipe diameter in the T-junction can redistribute the mass flow rate. Different diameter selected methods can provide a fine adjustment of mass flow rate for better inflation quality. 4) Almost all the parameters can be mutually influenced. Considering the combined effects of the diameter, the number and the position, we have established mathematical equations to seek the optimal parameters for better efficiency and quality of inflation process.