Biography
Prof. Sergey Timushev
Prof. Sergey Timushev
Moscow Aviation Institute (National Research University), Moscow, Russia
Title: Unsteady Flow and Pressure Pulsations in Bladed Machines
Abstract: 

Bladed machines operation is accompanied by pressure pulsations in flow paths and by hydrodynamic vibration of structure members. Great attention is paid to measurements and control of a level of pressure pulsations and vibration both in operation and, in particular, during development testing. Pressure pulsations and vibration bear information on the dynamic stresses the engine structure members are subjected to. Dynamic stresses imposed on the effective static stresses result in fatigue failure of structure members. The higher are static and dynamic stresses, the more likely is the fatigue failure of a member and the shorter is non-failure operation life of the unit. A unique dependence between dynamic stresses, acting in specific members, and measured pressure pulsations and vibrations is usually unknown. A permissible level of pressure pulsations and vibration is determined experimentally in bench tests. Many studies both in Russia and abroad were dedicated to investigation of working fluid pressure pulsations, vibration and noise of centrifugal pumps and other turbomachines. The experimental data have shown direct relationship between pressure pulsations in the bladedmachine flow path and its vibration-noise characteristics. The presence of intensive pressure pulsations is typical for all types of centrifugal pumps and other radial turbomachines. Under certain conditions the pressure pulsations in the centrifugal pump outlet, for example, in outlet volute may reach the values hazardous for the structure integrity. The study of pressure pulsations in the pump cavity gives information on variable loads, acting on structure members, it has been found during measurement by strain gauges of dynamic stresses at leading edges of guide vanes of the centrifugal pump that in the range of flow rates of 0.6 – 1.0 of its optimal value the dynamic stresses are directly proportional to the amplitudes of pressure pulsations. Physical-and-mathematical model of pulsating flow in the centrifugal pump developed by taking into account non-linear character of oscillations generation process and acoustic nature of their propagation in the working circuit of the pump.

 

Keywords

Unsteady Flow, Pressure Pulsations, Hydrodynamic Vibration, Bladed Machine, BPF Component,Acoustic-Vortex Decomposition
Biography: 

Serguei Timouchev was born in 1955, graduated from Moscow Aviation Institute in 1978.

Since 1980, heworked for Buran space program and from 1992, within Moscow Aviation Institute, for Arianne-Vulcain project. He made many experimental and computational studies in the field of pressure pulsation and vibration in centrifugal turbopump units of Liquid Propellant Rocket Engines (LPRE), including reduction of pressure pulsation and vibration caused by cavitation, reverse flows, acoustical amplification. In 1986, he proposed the original method for numerical modeling of pressure pulsation in centrifugal machines.

The last decade he works on the problem of computational prediction of pressure pulsation in centrifugal pumps and ventilators and reduction of vibration and noise in such machines. In 2002-2004 he worked for EU scientific project NORMA on noise and vibration reduction in high speed ships.

He received his Dr.Tech.Sc. degree in 1996 on numerical modeling of pressure pulsation in centrifugal pumps. He is author and co-author of more than 100 scientific publications and is an affiliate member of the INCE/Europe, member of IIAV and ASME.

Currently he works as a professor of turbomachinery in Department 202 “Rocket Engines” and head of Laboratory of Numerical Modeling in Scientific Research Center of New Technologies in Moscow Aviation Institute.