Research Of Air Flow Excitation Force Of Leaf Peak Clearance Evocable By Impeller Eccentricity On Large Axial Rotary Machines

Airflow just for working medium place a premium on air flow excitation, which belong to self-excited vibration. Along with development of science and technology, especially for the 15th development program of the state, we must advance the using efficiency of energy sources and building economical society, then big power and high parameter rotary machines will be widely used. Along with the advance of rotary machines'parameter, the force of air flow excitation will be advanced, finally there will effect the security of the rotary machines. The air flow excitation force of leaf peak clearance evocable by impeller eccentricity is the important part of the air flow excitation force, so the research of it is very important too.The generation mechanism and characteristics of air flow excitations in rotary machines are analyzed and summarized along with an overview of the general situation of the research on air flow excitations both at home and abroad. Depend on the reference of formers'research, using theoretic method fetched the calculate formulary of air flow excitations force which considered dynamic and static eccentricity of the rotor, and get across of the formulary calculated two cases. Through the formulary and results, we can analyzed that dynamic eccentricity and static eccentricity were uniformity important of the air flow excitations force, no one can be neglected. Furthermore, according as the calculate result we gained the value of the efficiency coefficientβ, the calculate result was very closed to the research of other scholar.Through the software of Fluent simulated one stair of eccentricity impeller in a large axial induced draft fan, calculated the force of air flow excitations under static eccentricity, the result was very closed to the result of theoretic calculate. Through the simulation we can discover that the force inverse proportion with leaf peak clearanceδand direct proportion with eccentricity of impeller e and rotate speed n.Primarily accomplished the design of the test-bed for the air flow excitation force of leaf peak clearance evocable by impeller eccentricity, put forward the testing method of dynamic and static eccentricity air flow excitations force, and give out the testing method of static air flow excitations force which caused by air proportion entrance. Across of the testing method of steam flow excitations force, we can test the value of it and will farther more advanced the research of theory and experiment. Moreover, we can explain the phenomenon of air flow excitations by steam proportion entrance through above-mentioned test method.Finally, across of the analysis of currently research, point out the problems existing and forecast of the future research.