scholarly journals Influence of Radial Inflow on Rotor-Stator Cavity Pressure Distributions

1994 ◽  
Author(s):  
Kenneth J. Hart ◽  
Alan B. Turner
Keyword(s):  
Gas Turbine ◽  
Fluid Dynamic ◽  
Gas Turbine Engine ◽  
Design Tool ◽  
Cfd Modelling ◽  
Turbine Engine ◽  
Cfd Models ◽  
Pressure Distributions ◽  
Engine Design ◽  
Gap Ratio

Rig tests and computational fluid dynamic (CFD) modelling have been used to improve the understanding of the effects of component geometry and air bleed flows on the pressure and velocity variations in the rotor-stator cavity found typically behind the impeller of a gas turbine engine centrifugal compressor. Ranges of axial gap ratio and bleed throughflow typical of those found in current gas turbine engine design have been investigated with close attention to radial inflow (centripetal) bleeds with and without initial swirl. CFD models have been constructed corresponding to the test conditions to assist in the understanding of the test data and to validate the computational methods. These methods can be used to extend the ranges of geometry, rotational Reynolds number and throughflows studied with greater confidence, thereby providing a design tool for direct use in the gas turbine industry.

Integrating Systems Engineering Into the USAF Academy Capstone Gas Turbine Engine Course

2011 ◽  
Author(s):  
August J. Rolling ◽  
Aaron R. Byerley ◽  
Charles F. Wisniewski
Keyword(s):  
Engineering Design ◽  
Gas Turbine ◽  
Systems Engineering ◽  
Aircraft Engine ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Technical Management ◽  
Engine Design ◽  
Aeronautical Engineering ◽  
The Many

This paper is intended to serve as a template for incorporating technical management majors into a traditional engineering design course. In 2002, the Secretary of the Air Force encouraged the USAF Academy to initiate a new interdisciplinary academic major related to systems engineering. This direction was given in an effort to help meet the Air Force’s growing need for “systems” minded officers to manage the development and acquisition of its ever more complex weapons systems. The curriculum for the new systems engineering management (SEM) major is related to the “engineering of large, complex systems and the integration of the many subsystems that comprise the larger system” and differs in the level of technical content from the traditional engineering major. The program allows emphasis in specific cadet-selected engineering tracks with additional course work in human systems, operations research, and program management. Specifically, this paper documents how individual SEM majors have been integrated into aeronautical engineering design teams within a senior level capstone course to complete the preliminary design of a gas turbine engine. As the Aeronautical engineering (AE) cadets performed the detailed engine design, the SEM cadets were responsible for tracking performance, cost, schedule, and technical risk. Internal and external student assessments indicate that this integration has been successful at exposing both the AE majors and the SEM majors to the benefits of “systems thinking” by giving all the opportunity to employ SE tools in the context of a realistic aircraft engine design project.

Validation and Comparison of Strip Seal Designs for Gas Turbine Engine Nozzle Guide Vanes

2008 ◽  
Author(s):  
Arash Farahani ◽  
Peter Childs
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Gas Turbine Engine ◽  
Experimental Comparison ◽  
Cfd Modelling ◽  
Guide Vanes ◽  
Turbine Engine ◽  
Seal Design ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes

Strip seals are commonly used to prevent or limit leakage flows between nozzle guide vanes (NGV) and other gas turbine engine components that are assembled from individual segments. Leakage flow across, for example, a nozzle guide vane platform, leads to increased demands on the gas turbine engine internal flow system and a rise in specific fuel consumption (SFC). Careful attention to the flow characteristics of strip seals is therefore necessary. The very tight tolerances associated with strip seals provides a particular challenge to their characterisation. This paper reports the validation of CFD modelling for the case of a strip seal under very carefully controlled conditions. In addition, experimental comparison of three types of strip seal design, straight, arcuate, and cloth, is presented. These seals are typical of those used by competing manufacturers of gas turbine engines. The results show that the straight seal provides the best flow sealing performance for the controlled configuration tested, although each design has its specific merits for a particular application.

Review of Titanium Application in Gas Turbine Engines

2003 ◽  
Author(s):  
Charles W. Elrod
Keyword(s):  
Gas Turbine ◽  
Selection Process ◽  
Gas Turbine Engine ◽  
Advanced Materials ◽  
Turbine Engines ◽  
Turbine Engine ◽  
Long Run ◽  
Engine Design ◽  
Basic Studies ◽  
Burn Rate

With the continuing desire to make engines with a high thrust to weight advantage, titanium is the metal of choice for the gas turbine engine. The use of titanium in the engine must be considered with reasonable care. The metal has been known to combust under certain conditions. The Air Force conducted a number of studies to evaluate the use of titanium in the engine and in other environments. As a result of the studies the effects the environment, the alloying, the thickness and burn rate were among the conditions evaluated. Also the studies were conducted to determine the self-sustained combustibility of titanium and its alloys in the various situations that were established for the evaluations. The studies considered fifty-four different titanium alloys, which included a sample of most of the current materials, some of the advanced materials and a number of unusual alloys. This effort resulted in the identification of easy to burn, harder to burn and very difficult to burn alloys. With this information we can now look at issues related to where certain alloys would benefit the compressor the most. For example, Ti 6Al4V would most likely be used in the fan section of the compressor, due to the thickness of the blade, the low pressure in that section and the gap above the blade. The compressor has a number of issues that can be partially resolved with the use of titanium in a manner that is consistent with safe procedures. This report will examine these issues and present some considerations that should be considered when applying titanium to the gas turbine engine. This paper will look into the turbine engine and examine those areas where the potential for compressor fires are likely and make suggestions on ways to limit the potential for catastrophic damage and in the long run make the engine more resilient in the future. This paper will examine the problems that have followed the engine development with titanium as one of the major players in the selection process. We will describe some of the technology which makes the use of titanium safer. Titanium will be with the engine technology for some time and the goal of most design and research studies should be to make that time as safe and reliable as possible. This paper will show how research can provide the valuable link from basic studies to engine design.

Thermo Fluid Dynamic Analysis of a Gas Turbine Transition-Piece

2014 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Lorenzo Mazzei ◽  
Giovanni Riccio ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Fluid Dynamic ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Thermal Loads ◽  
Turbine Engine ◽  
Transition Piece

The transition-piece of a gas turbine engine is subjected to high thermal loads as it collects high temperature combustion products from the gas generator to a turbine. This generally produces high thermal stress levels in the casing of the transition piece, strongly limiting its life expectations and making it one of the most critical components of the entire engine. The reliable prediction of such thermal loads is hence a crucial aspect to increase the transition-piece life span and to assure safe operations. The present study aims to investigate the aero-thermal behaviour of a gas turbine engine transition-piece and in particular to evaluate working temperatures of the casing in relation to the flow and heat transfer situation inside and outside the transition-piece. Typical operating conditions are considered to determine the amount of heat transfer from the gas to the casing by means of CFD. Both conjugate approach and wall fixed temperature have been considered to compute the heat transfer coefficient, and more in general, the transition-piece thermal loads. Finally a discussion on the most convenient heat transfer coefficient expression is provided.

Integrating Systems Engineering Into the USAF Academy Capstone Gas Turbine Engine Course

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
August J. Rolling ◽  
Aaron R. Byerley ◽  
Charles F. Wisniewski
Keyword(s):  
Engineering Design ◽  
Gas Turbine ◽  
Air Force ◽  
Systems Engineering ◽  
Aircraft Engine ◽  
The United States ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Engine Design ◽  
Aeronautical Engineering

This paper is intended to serve as a template for incorporating technical management majors into a traditional engineering design course. In 2002, the Secretary of the Air Force encouraged the United States Air Force (USAF) Academy to initiate a new interdisciplinary academic major related to systems engineering. This direction was given in an effort to help meet the Air Force’s growing need for “systems” minded officers to manage the development and acquisition of its ever more complex weapons systems. The curriculum for the new systems engineering management (SEM) major is related to the “engineering of large, complex systems and the integration of the many subsystems that comprise the larger system” and differs in the level of technical content from the traditional engineering major. The program allows emphasis in specific cadet—selected engineering tracks with additional course work in human systems, operations research, and program management. Specifically, this paper documents how individual SEM majors have been integrated into aeronautical engineering design teams within a senior level capstone course to complete the preliminary design of a gas turbine engine. As the Aeronautical Engineering (AE) cadets performed the detailed engine design, the SEM cadets were responsible for tracking performance, cost, schedule, and technical risk. Internal and external student assessments indicate that this integration has been successful at exposing both the AE majors and the SEM majors to the benefits of “systems thinking” by giving all the opportunity to employ SE tools in the context of a realistic aircraft engine design project.

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