Gas Turbine Engine Simulation Research Articles

Performance of a Complaint Foil Seal in a Small Gas Turbine Engine Simulator Employing a Hybrid Foil/Ball Bearing Support System

Operation of a non-contact compliant gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a small gas turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS. The experimental results indicate superior performance of the CFS over the two other types of seals. Unlike brush seal, CFS showed no evidence of rub or induced wear on the journal or seal surface. Presented at the 56th Annual Meeting Orlando, Florida May 20–24, 2001

Extensible object model for gas turbine engine simulation

This paper presents an extensible object model for gas turbine engine performance simulation. The extension method for gas path balancing is analyzed and a new design rationale is developed to overcome deficiencies of the traditional component-based object modeling method. A class framework implementing this rationale is described and the dynamic performance of a three-shaft gas turbine engine is simulated to evaluate the model’s effectiveness.

Computational Simulation of Gas Turbines: Part 2—Extensible Domain Framework

This paper describes the design concepts and object-oriented architecture of Onyx, an extensible domain framework for computational simulation of gas turbine engines. Onyx provides a flexible environment for defining, modifying, and simulating the component-based gas turbine models described in Part 1 of this paper. Using advanced object-oriented technologies such as design patterns and frameworks, Onyx enables users to customize and extend the framework to add new functionality or adapt simulation behavior as required. A customizable visual interface provides high-level symbolic control of propulsion system construction and execution. For computationally-intensive analysis, components may be distributed across heterogeneous computing architectures and operating systems. A distributed gas turbine engine model is developed and simulated to illustrate the use of the framework. [S0742-4795(00)02403-0]

A Computational Model for the Study of Gas Turbine Combustor Dynamics

A dynamic combustor model is developed for inclusion into a one-dimensional full gas turbine engine simulation code. A flux-difference splitting algorithm is used to numerically integrate the quasi-one-dimensional Euler equations, supplemented with species mass conservation equations. The combustion model involves a single-step, global finite-rate chemistry scheme with a temperature-dependent activation energy. Source terms are used to account for mass bleed and mass injection, with additional capabilities to handle momentum and energy sources and sinks. Numerical results for cold and reacting flow for a can-type gas turbine combustor are presented. Comparisons with experimental data from this combustor are also made.

Networked agents for scientific computing

The thesis of this article is that agent based computing provides important advantages for scientific computing. We present this thesis in the context of a particular application, the simulation of gas turbine engines. This application is typical in that it involves an enormously complex device of great economic importance, one whose design is continually evolving to achieve higher value and to fit new uses. Ideally, a designer would change some aspect of the engine and then run a simulation to see how the performance, cost, durability, etc., change. Such a simple approach will be infeasible for the foreseeable future because the complete simulation of an engine design requires days, weeks or even years on petaflops class computing systems. Thus the design process and simulation software must be configurable so that a simulation can focus on particular aspects of the engine. For example, in designing a new turbine blade (they do not all have the same shape) one might (a) model the blade itself very accurately, (b) model the air flow field and structure near the blade with moderate accuracy, (c) model the air flow fields and structures further away roughly, and

98/00599 Modelling and simulation of combined gas turbine engine and heat pipe system for waste heat recovery and utilization

98/00599 Modelling and simulation of combined gas turbine engine and heat pipe system for waste heat recovery and utilization

Modeling and simulation of combined gas turbine engine and heat pipe system for waste heat recovery and utilization

The results of a modeling and simulation study are presented for a combined system consisting of a gas turbine engine, a heat pipe recovery system and an inlet-air cooling system. The presentation covers performance data related to the gas turbine engine with precooled air intake as coupled to the water-in-copper heat pipe recovery system. This is done by matching the two mathematical models. The net power output is improved by 11% when the gas turbine engine is supplied with cold air produced by the heat-pipe recovery and utilization system. It is further concluded from the results produced by the combined mathematical model that the thermal efficiency of the gas turbine engine rises to 6% at 75% part load. It is to be anticipated that this rising trend in increases of thermal efficiency of the gas turbine engine would continue for operations at other (lower) part load conditions.

The Unsteady State Simulation of Gas Turbine Engines for Training Purposes

The Unsteady State Simulation of Gas Turbine Engines for Training Purposes

Turbotrans — Α Programming Language for the Performance Simulation of Arbitrary Gas Turbine Engines with Arbitrary Control Systems

Turbotrans — Α Programming Language for the Performance Simulation of Arbitrary Gas Turbine Engines with Arbitrary Control Systems

Component Mode Synthesis of Large Rotor Systems

A scheme is presented for calculating the vibrations of large multi-component flexible rotor systems based on the component mode synthesis method. It is shown that, by a modal expansion of the elastic interconnecting elements, the system modal equation can be conveniently constructed from the undamped eigen representations of the component subsystems. The capability of the component mode method is demonstrated in two examples: a transient simulation of a two-spool gas turbine engine equipped with a squeeze-film damper; and an unbalance response analysis of the Space Shuttle Main Engine oxygen turbopump in which the dynamics of the rotor and the housing are both considered.

Digital simulation of nonlinear dynamic systems using standard FORTRAN

The capability to obtain either transient or equilibrium solutions for systems of mixed algebraic and differential equations, the latter independently of the stability of the system, is a useful tool for investigation of lumped thermo-dynamic models having unstable regimes of operation. A general-purpose simulation program giving these facilities is described. The program is written in standard Fortran to permit easy implementation on any computer. Its application is illustrated by reference to simulation of gas-turbine engines.