Numerical Simulation Of Ice Accretion And Study For Icing Scaling Law On Aero-engine Entry Components

What is worse that ice accretion on the aero-engine entry components(such as the struts and the centre conical body) would occur at some special meteoric conditions ice changes, such as thickening, the mass flow rate of airflow and flow area would reduce, that would lead to worsened engine performance. If the Ice Shedding into the aero-engine entry, it will cause the damage of the engine, even endanger the flight.This paper got a deep study on icing phenomenon on an entry parts of aero-engine and the centre conical body are investigated systematically through icing wind tunnel tests and numerical simulation methods. In this article, some studies have been made on design of icing tests. Based on the icing scaling law, the method of icing wind tunnel tests on an entry parts of aero-engine has been established.The main research of this thesis are as follows:(1)Based on the time multi-step method, a three-dimensional icing model on an entry parts of aero-engine of stationary components for ice calculation is established in the paper which takes into consideration the effect of runback water. On this basis, a three-dimensional ice research code for ice calculation is developed.The fundamental steps of numerical simulation on three-dimensional ice accretion, and thermodynamic process are thoroughly investigated :(1) The computation method for two-phase flow based on Euler-Lagrange method is investigated;(2) Program and steps for calculating droplets impingement characteristic are offered. A statistical method is proposed to calculate the water collection efficiency is used to simulate the motion of super-cooled water droplets. The computer code of the statistical method is developed. water collection efficiency of two dimensional NACA0012 airfoil and three dimensional Axisymmetric inlet are numerical simulated, computation agree with experimental results;(3) Based on the classic icing model propose by Messinger,A modified thermodynamic three dimensional Messinger model of icing is proposed in the paper which takes into consideration the effect of runback water. Then the numerical method for solving the model is developed, which employs iterative technology.(4)Dynamic Mesh Model for icing numerical simulation are established.Iced airfoil with three-dimensional characteristics such as MS-317 airfoil and GLC-30 airfoil,are numerical simulated. Ice shapes from computation agree with experimental results and Ice accretion on a three dimensional stationary, which indicate the validity of A three-dimensional ice research code in this paper. On this basis, centre conical body is calculated, the qualitative analysis of results.(2) A numerical model is proposed for three-dimensional ice calculation is used to simulate the spinning cone of aero-engine. The effects of rotating on flow field, and the effects of flow field on water droplet impingement, and the effects of centrifugal force on water throw-off are discussed in detail. A statistical method is proposed to calculate the water collection efficiency and icing for spinning part of aero-engine. This article studies the calculating method of water droplet impingement for the spinning cone and uses the method for different cone angles and rotational speeds. A type of spinning cone are numerical simulated. Ice accretion on spinning cone icing wind tunnel experiments was partially finished. Ice shapes from experimental results with computation agree, which indicate the validity of numerical calculation method and model in this paper. On this basis, this article studies the effects of MVD, inlet velocity and surrounding temperature on ice accretion under a certain speed.(3) In this paper,a dimensionless quantities of the icing scaling law on spinning cone is proposed. It can be used in icing wind tunnel test as the theoretic basis of test and its parameters selection. The principle of rotating icing scaling is explained, then the icing scaling law on spinning cone is established, which considered the rotating effect. A method to choose the test parameters is proposed based on this icing scaling law and a computational program is developed in this study. The reliability of the numerical calculation method is verified by the experimental data, The scaled model is simulated by this numerical method and the results of the full model and scaled model are in good agreement, which shows the correctness of the spinning cone icing scaling law.