Numerical Simulation Of The Inner Flow Field And The Optimal Design Of Hema-type ATY Nozzle Based On Fluent

In this paper, the inner flow fields of twelve Hema-type ATY nozzles which have different structure and parameters are simulated by the Fluent software, which is based on the CFD (Computational Fluid Dynamics) theory. Due to the complicated structure and high accuracy of the ATY nozzle, its air field characteristics can not be tested directly, so the numerical simulation is applied in this paper.The paper is consisted of research as follows:Mainly introduced the research value and its content; A mathematical model is established based on aerodynamic theory. Twelve ATY nozzles are designed with different structure and parameters and the3D model of these ATY nozzles are built by PRO/e. The newly designed nozzles are:the first group---the nozzles with different parameters, which have two air-inlet holes distributed in one circle; the second group—the nozzles have more than one air-inlet hole compared with the first group; the third group—the nozzles are distributed in two circle compared with the second group; The solid meshes and boundary conditions are set; the specific steps of numerical simulation are introduced. Then the simulation results are analyzed. And the results are as follows:the distribution of the air flow speed along axial and radial direction in the nozzle is investigated, based on the above analysis, it is concluded that the inner flow field of ATY nozzle is a complex unsteady flow with intense impulse and vortex.; When the strand comes through the nozzle, the location of the single strand is continuously changing because of the mutual effect of the jet stream and the loop’s tension with a periodic perturbation in the nozzle; There are great velocity and pressure gradient both in the radial and axial directions, which results in the different slippage of different strands in different directions; Thus, it is in favor of the forming of steady loop. By considering the merits and demerits of each nozzle, one best structure and parameters combination of ATY nozzle is fixed. Shaanxi Blue sky line manufacturing Limited Liability Company is entrusted to do the testing of the best structure nozzle in this paper, and the tests effect are ideal. The results show that the producing speed of the ATY nozzle that in the paper can reach up to350-500m/min under the supplied gas pressure of0.75MPa-1.2MPa and it can be applied to produce the yarn with the denier of30-3000dtex.