scholarly journals Solving current problems in engineering system dynamics

2021 ◽  
Vol 2021 (2) ◽  
pp. 3-19
Author(s):  
O.V. Pylypenko ◽  
Keyword(s):  
Mathematical Model ◽  
System Dynamics ◽  
Gas Turbine ◽  
Launch Vehicle ◽  
Gas Turbine Engine ◽  
Protection System ◽  
Liquid Propellant ◽  
Turbine Engine ◽  
Vibration Protection ◽  
Engine Components

This paper overviews the main results obtained over the past few years at the Department of Hydromechanical Systems Dynamics and Vibration Protection Systems, Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, in the solution of current problems in the dynamics of liquid-propellant rocket engines (LPREs), liquid-propellant launch vehicle pogo stability, vibration protection system dynamics, the gas dynamics of aircraft gas turbine engine components, and the dynamics of hydraulic systems with cavitating elements. These results are as follows. A mathematical model of LPRE pump dynamics was developed. The model complements a hydrodynamic model of LPRE cavitating pumps by allowing a mathematical simulation of choking regimes. An approach was developed to the construction of a nonlinear mathematical model of LPRE hydraulic line filling. The approach allows one to automatically change, if necessary, the finite element partitioning scheme of a hydraulic line in the process of its filling during LPRE startup calculations. An investigation was conducted into the startup dynamics of a multiengine liquid-propellant propulsion system that consists of four staged-combustion oxidizer-rich LPRDs with account for the possibility of their nonsimultaneous startup. The maximum values of oxidizer and fuel pressure surges and undershoots at the liquid-propellant jet system (LPJS) inlet at an engine spartup and shutdown were determined and used in determining the LPJS operability at the startup and shutdown of the RD861K sustainer engine. The pogo stability of the Cyclone-4M launch vehicle was analyzed analytically using Nyquist’s criterion. A numerical approach was developed to characterizing acoustic oscillations of the combustion products in annular rocket combustion chambers with account for the configuration features of the fire space and the variation of the physical properties of the gaseous medium with the axial length of the chamber. A prototype vibration protection system was developed and made, and its dynamic tests confirmed its high efficiency in damping impact and harmonic disturbances. Approaches were developed to the aerodynamic improvement of aircraft gas turbine engine components. Topical problems in solids grinding in a liquid medium with the use a cavitation pulse technology were solved.

Flexible manufacturing in repair of gas turbine engine components

1992 ◽  
Author(s):  
KIRK D ◽  
ANDREW VAVRECK ◽  
ERIC LITTLE ◽  
LESLIE JOHNSON ◽  
BRETT SAYLOR
Keyword(s):  
Gas Turbine ◽  
Flexible Manufacturing ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Engine Components

Life assessment of a high temperature probe designed for performance evaluation and health monitoring of an aero gas turbine engine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Benny George ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Performance Evaluation ◽  
Gas Turbine ◽  
Health Monitoring ◽  
Gas Turbine Engine ◽  
Life Assessment ◽  
Exhaust Gas ◽  
Cycle Fatigue ◽  
Creep Life ◽  
Turbine Engine ◽  
Engine Components

AbstractTemperature probes of different designs were widely used in aero gas turbine engines for measurement of air and gas temperatures at various locations starting from inlet of fan to exhaust gas from the nozzle. Exhaust Gas Temperature (EGT) downstream of low pressure turbine is one of the key parameters in performance evaluation and digital engine control. The paper presents a holistic approach towards life assessment of a high temperature probe housing thermocouple sensors designed to measure EGT in an aero gas turbine engine. Stress and vibration analysis were carried out from mechanical integrity point of view and the same was evaluated in rig and on the engine. Application of 500 g load concept to clear the probe design was evolved. The design showed strength margin of more than 20% in terms of stress and vibratory loads. Coffin Manson criteria, Larsen Miller Parameter (LMP) were used to assess the Low Cycle Fatigue (LCF) and creep life while Goodman criteria was used to assess High Cycle Fatigue (HCF) margin. LCF and HCF are fatigue related damage from high frequency vibrations of engine components and from ground-air-ground engine cycles (zero-max-zero) respectively and both are of critical importance for ensuring structural integrity of engine components. The life estimation showed LCF life of more than 4000 mission reference cycles, infinite HCF life and well above 2000 h of creep life. This work had become an integral part of the health monitoring, performance evaluation as well as control system of the aero gas turbine engine.

Life assessment of a high temperature probe designed for performance evaluation and health monitoring of an aero gas turbine engine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Benny George ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Performance Evaluation ◽  
Gas Turbine ◽  
Health Monitoring ◽  
Gas Turbine Engine ◽  
Life Assessment ◽  
Exhaust Gas ◽  
Cycle Fatigue ◽  
Creep Life ◽  
Turbine Engine ◽  
Engine Components

Abstract Temperature probes of different designs were widely used in aero gas turbine engines for measurement of air and gas temperatures at various locations starting from inlet of fan to exhaust gas from the nozzle. Exhaust Gas Temperature (EGT) downstream of low pressure turbine is one of the key parameters in performance evaluation and digital engine control. The paper presents a holistic approach towards life assessment of a high temperature probe housing thermocouple sensors designed to measure EGT in an aero gas turbine engine. Stress and vibration analysis were carried out from mechanical integrity point of view and the same was evaluated in rig and on the engine. Application of 500 g load concept to clear the probe design was evolved. The design showed strength margin of more than 20% in terms of stress and vibratory loads. Coffin Manson criteria, Larsen Miller Parameter (LMP) were used to assess the Low Cycle Fatigue (LCF) and creep life while Goodman criteria was used to assess High Cycle Fatigue (HCF) margin. LCF and HCF are fatigue related damage from high frequency vibrations of engine components and from ground-air-ground engine cycles (zero-max-zero) respectively and both are of critical importance for ensuring structural integrity of engine components. The life estimation showed LCF life of more than 4000 mission reference cycles, infinite HCF life and well above 2000 h of creep life. This work had become an integral part of the health monitoring, performance evaluation as well as control system of the aero gas turbine engine.

An Integrated Approach for Gas Turbine Engine Simulation

2000 ◽  
Author(s):  
Zhiwu Xie ◽  
Ming Su ◽  
Shilie Weng
Keyword(s):  
Gas Turbine ◽  
Local Area Network ◽  
Integrated Approach ◽  
Local Area ◽  
Gas Turbine Engine ◽  
Future Research ◽  
Area Network ◽  
Turbine Engine ◽  
Engine Simulation ◽  
Engine Components

Abstract The static and transient performance of a gas turbine engine is determined by both the characteristics of the engine components and their interactions. This paper presents a generalized simulation framework that enables the integration of different component and system simulation codes. The concept of engine simulation integration and its implementation model is described. The model is designed as an object-oriented system, in which various simulation tasks are assigned to individual software components that interact with each other. A new design rationale called “message-based modeling” and its resulting class structure is presented and analyzed. The object model is implemented within a heterogeneous network environment. To demonstrate its flexibility, the codes that deal with different engine components are separately programmed on different computers running various operating systems. These components communicate with each other via a CORBA compliant ORB, which simulates the overall performance of an engine system. The resulting system has been tested on a Local Area Network (LAN) to simulate the transient response of a three-shaft gas turbine engine, subject to small fuel step perturbations. The simulation results for various network configurations are presented. It is evident that in contrast to a standalone computer simulation, the distributed implementation requires much longer simulation time. This difference of simulation efficiency is analyzed and explained. The limitations of this endeavor, along with some future research topics, are also reported in this paper.

Mathematical model identification of gas turbine engine with account for initial data uncertainty

2021 ◽  
Vol 28 (3) ◽  
pp. 171-185
Author(s):  
Oleg Baturin ◽  
Paul Nikolalde ◽  
Grigorii Popov ◽  
Anastssia Korneeva ◽  
Ivan Kudryashov
Keyword(s):  
Mathematical Model ◽  
Initial Data ◽  
Gas Turbine ◽  
Model Identification ◽  
Gas Turbine Engine ◽  
Data Uncertainty ◽  
Turbine Engine

Ceramic Composites for Gas Turbine Engines via a New Process

1989 ◽  
Author(s):  
G. H. Schiroky ◽  
A. W. Urquhart ◽  
B. W. Sorenson
Keyword(s):  
Gas Turbine ◽  
Joint Venture ◽  
New Technology ◽  
Ceramic Composites ◽  
Gas Turbine Engine ◽  
Molten Metals ◽  
Oxidation Reactions ◽  
Turbine Engine ◽  
New Process ◽  
Engine Components

A new process for ceramic composites involves the growth of ceramic matrices through shaped preforms using directed oxidation reactions of molten metals. The preforms may consist of reinforcing fibers, whiskers, platelets, or particles, as needed to produce the desired properties in the finished component. This new technology is being developed by Lanxide Corporation and is being applied to gas turbine engine components by Du Pont Lanxide Composites Inc., a joint venture. The paper includes a description of the technology and a discussion of the status of its application to materials for gas turbine engine components.

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