scholarly journals Aircraft Gas Turbine Engine Testing

2019 ◽  
pp. 39-44
Author(s):  
Stanislav Fábry ◽  
Miroslav Spodniak ◽  
Peter Gašparovič ◽  
Peter Koščák

The paper deals with testing of aircraft gas turbine engines. The main goal of the research is to propose and design testing sequence for a new or rebuilt engine. All factors and circumstances are described, including surroundings of the engine under test. Prerequisite knowledge is introduced, including the theory of testing, description of test beds, the methods of measurement of engine parameters and special factors that affect engine performance. Some examples of real testing facilities are mentioned. The result of the work is a proposal of test cycle, that can be modified according to engine purpose and specification.

Author(s):  
P. A. Phillips ◽  
Peter Spear

After briefly summarizing worldwide automotive gas turbine activity, the paper analyses the power plant requirements of a wide range of vehicle applications in order to formulate the design criteria for acceptable vehicle gas turbines. Ample data are available on the thermodynamic merits of various gas turbine cycles; however, the low cost of its piston engine competitor tends to eliminate all but the simplest cycles from vehicle gas turbine considerations. In order to improve the part load fuel economy, some complexity is inevitable, but this is limited to the addition of a glass ceramic regenerator in the 150 b.h.p. engine which is described in some detail. The alternative further complications necessary to achieve satisfactory vehicle response at various power/weight ratios are examined. Further improvement in engine performance will come by increasing the maximum cycle temperature. This can be achieved at lower cost by the extension of the use of ceramics. The paper is intended to stimulate the design application of the gas turbine engine.


Author(s):  
A. Carelli

The experience acquired in developing an automotive gas-turbine engine is traced. Problems of design, construction, and development unique to a small gas-turbine engine and its application to an automobile are discussed. The engine performance and operational characteristics are then described. Finally, there is a discussion of the problems that must be solved before gas-turbine engines may successfully compete with reciprocating engines in automotive road transport.


Author(s):  
B. Roth ◽  
J. de Luis

This paper presents and evaluates a lost thrust method for analysis of thermodynamic performance in gas turbine engines. This method is based on the definition of a hypothetical ideal engine that is used as a point of comparison to evaluate performance of the real engine. Specifically, component loss is quantified in terms of decrements in thrust of the real engine relative to the ideal engine having the same design point cycle. These lost thrust decrements provide a basis for accurately evaluating the performance cost of component losses while simultaneously accounting for all component interactions. The analysis algorithm is formally developed in detail and is then demonstrated for a typical separate flow turbofan engine. Various scenarios are examined and the results of these exercises are used to draw conclusions regarding the strengths and weaknesses of this approach to gas turbine performance analysis.


Author(s):  
David W. Richerson

Since the invention of the gas turbine engine, engineers have continuously strived to achieve higher operating temperature and improved thermal efficiency. Ceramic-based materials were considered in the 1940s and 1950s, but did not have adequate properties to survive the thermal shock and high temperature conditions. By the end of the 1960s, new materials were developed in the silicon nitride and silicon carbide families that appeared to have potential. Substantial efforts have subsequently been conducted worldwide. These efforts have identified and sought solutions for key challenges: improvement in properties of candidate materials, establishing a design and life prediction methodology, generating a material database, developing cost-effective fabrication of turbine components, dimensional and non-destructive inspection, and validation of the materials and designs in rig and engine testing. Enormous technical progress has been made, but ceramic-based turbine components still have not reached bill-of-materials status. There are still problems that must be solved. In addition, metals-based technology has not stood still. Implementation of sophisticated cast-in internal cooling passages, development of directionally solidified and later single crystal superalloy hot section components, improved alloys, and use of ceramic thermal barrier coatings have combined to allow thermal efficiency increases that exceed the 1970s goals that engineers thought could only be achieved with ceramics. As a result of these metal and design advances, the urgency for use of ceramics has decreased. Emphasis of this paper is on review of the key challenges of implementing ceramic components in gas turbine engines, progress towards solving these challenges, some challenges that still need to be resolved, and a brief review of how technology from the turbine developments has been successfully spun off to important products.


Author(s):  
Ilan Arush ◽  
Marilena D Pavel ◽  
Max Mulder

The process of empirical models evaluation is at the core business of experimental flight-testing data analysis. Accurate and convenient flight-testing of helicopter engine(s) available power is crucial for predicting the total helicopter performance. Common practice in estimation of in-flight helicopter gas turbine engine power consists of a reduction of flight-test data into simplistic single-variable analysis approach. While such an approach is convenient for practical use, it often results in unrealistic predictions of the available engine(s) power. A novel approach for the helicopter available power problem is the so-called Multivariable Polynomial Optimization under Constraints method. In this method, 18 regressors, constructed from the engine non-dimensional parameters, are used to define empirical polynomial models. This paper is intended to complement the Multivariable Polynomial Optimization under Constraints method and answer the question of which multivariable polynomial can be generally used in representing helicopter gas-turbine engine performance? In this sense, a variety of seven gas-turbine engines installed on different helicopters are analyzed, each one giving 512 possible polynomial models to be used for available-power calculations. While conventional statistical methods of hypothesis-testing failed in providing the answer to the question stated above of which the best general empirical model for representing engine performance is, an alternative approach based on the Singular-Value-Decomposition theorem, was proven successful in providing the answer. Moreover, this approach presented in the paper yielded a short list of 10 simple and convenient multivariable polynomials, best representing the performance of all seven engines analyzed as a group.


2021 ◽  
Vol 4 (8(112)) ◽  
pp. 59-66
Author(s):  
Ludmila Boyko ◽  
Vadym Datsenko ◽  
Aleksandr Dyomin ◽  
Nataliya Pizhankova

The design and adjustment of modern gas turbine engines significantly rely on the use of numerical research methods. This paper reports a method devised for calculating the thermogasdynamic parameters and characteristics of a turboshaft gas turbine engine. The special feature of a given method is a two-dimensional blade-by-blade description of the compressor in the engine system. Underlying the calculation method is a nonlinear mathematical model that makes it possible to describe the established processes occurring in individual nodes and in the engine in general. To build a mathematical model, a modular principle was chosen, involving the construction of a system of interrelated and coordinated models of nodes and their elements. The approach used in modeling a two-dimensional flow in the compressor makes it possible to estimate by calculation a significant number of parameters that characterize its operation. With the help of the reported method, it is possible to estimate the effect of changing the geometric parameters of the compressor height on the characteristics of the engine. To take into consideration the influence of variable modes of air intake or overflow in various cross-sections along the compressor tract, to determine the effect of the input radial unevenness on the parameters of the compressor and engine in general. To verify the method described, the calculation of thermogasdynamic parameters and throttle characteristics of a single-stage turboshaft gas turbine engine with a 12-stage axial compressor was performed. Comparison of the calculation results with experimental data showed satisfactory convergence. Thus, the standard deviation of the calculation results from the experimental data is 0.45 % for the compressor characteristics, 0.4 % for power, and 0.15 % for specific fuel consumption. Development and improvement of methods for calculating the parameters and characteristics of gas turbine engines make it possible to improve the quality of design and competitiveness of locally-made aircraft engines.


Author(s):  
D. C. Martin ◽  
F. R. Miller

The ability to fabricate materials and components needed to improve gas-turbine engine performance depends on an ability to achieve reliable joints. Solid-state joining provides this ability. Diffusion bonding of compressor blades, friction welding of engine rotors, and solid-state bonding of turbine shafts by coextrusion of dissimilar metals are discussed as examples of applications of solid-state bonding. Parts made by these techniques have successfully completed engine tests.


NDT World ◽  
2021 ◽  
pp. 58-61
Author(s):  
Aleksey Popov ◽  
Aleksandr Romanov

A large number of aviation events are associated with the surge of gas turbine engines. The article analyzes the existing systems for diagnostics of the surge of gas turbine engines. An analysis of the acoustic signal of a properly operating gas turbine engine was carried out, at which a close theoretical distribution of random values was determined, which corresponds to the studied distribution of the amplitudes of the acoustic signal. An invariant has been developed that makes it possible to evaluate the development of rotating stall when analyzing the acoustic signal of gas turbine engines. A method is proposed for diagnosing the pre-surge state of gas turbine engines, which is based on processing an acoustic signal using invariant dependencies for random processes. A hardware-software complex has been developed using the developed acoustic method for diagnosing the pre-surge state of gas turbine engines.


2021 ◽  
Author(s):  
Jeffrey S. Patterson ◽  
Kevin Fauvell ◽  
Dennis Russom ◽  
Willie A. Durosseau ◽  
Phyllis Petronello ◽  
...  

Abstract The United States Navy (USN) 501-K Series Radiological Controls (RADCON) Program was launched in late 2011, in response to the extensive damage caused by participation in Operation Tomodachi. The purpose of this operation was to provide humanitarian relief aid to Japan following a 9.0 magnitude earthquake that struck 231 miles northeast of Tokyo, on the afternoon of March 11, 2011. The earthquake caused a tsunami with 30 foot waves that damaged several nuclear reactors in the area. It was the fourth largest earthquake on record (since 1900) and the largest to hit Japan. On March 12, 2011, the United States Government launched Operation Tomodachi. In all, a total of 24,000 troops, 189 aircraft, 24 naval ships, supported this relief effort, at a cost in excess of $90.0 million. The U.S. Navy provided material support, personnel movement, search and rescue missions and damage surveys. During the operation, 11 gas turbine powered U.S. warships operated within the radioactive plume. As a result, numerous gas turbine engines ingested radiological contaminants and needed to be decontaminated, cleaned, repaired and returned to the Fleet. During the past eight years, the USN has been very proactive and vigilant with their RADCON efforts, and as of the end of calendar year 2019, have successfully completed the 501-K Series portion of the RADCON program. This paper will update an earlier ASME paper that was written on this subject (GT2015-42057) and will summarize the U.S. Navy’s 501-K Series RADCON effort. Included in this discussion will be a summary of the background of Operation Tomodachi, including a discussion of the affected hulls and related gas turbine equipment. In addition, a discussion of the radiological contamination caused by the disaster will be covered and the resultant effect to and the response by the Marine Gas Turbine Program. Furthermore, the authors will discuss what the USN did to remediate the RADCON situation, what means were employed to select a vendor and to set up a RADCON cleaning facility in the United States. And finally, the authors will discuss the dispensation of the 501-K Series RADCON assets that were not returned to service, which include the 501-K17 gas turbine engine, as well as the 250-KS4 gas turbine engine starter. The paper will conclude with a discussion of the results and lessons learned of the program and discuss how the USN was able to process all of their 501-K34 RADCON affected gas turbine engines and return them back to the Fleet in a timely manner.


Author(s):  
Peter D. Smout ◽  
Steven C. Cook

The determination of gas turbine engine performance relies heavily on intrusive rakes of pilot tubes and thermocouples for gas path pressure and temperature measurement. For over forty years, Kiel-shrouds mounted on the rake body leading edge have been used as the industry standard to de-sensitise the instrument to variations in flow incidence and velocity. This results in a complex rake design which is expensive to manufacture, susceptible to mechanical damage, and difficult to repair. This paper describes an exercise aimed at radically reducing rake manufacture and repair costs. A novel ’common cavity rake’ (CCR) design is presented where the pressure and/or temperature sensors are housed in a single slot let into the rake leading edge. Aerodynamic calibration data is included to show that the performance of the CCR design under uniform flow conditions and in an imposed total pressure gradient is equivalent to that of a conventional Kiel-shrouded rake.


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