scholarly journals Study of Design Modification Effects through Performance Analysis of a Legacy Gas Turbine Engine

2020 ◽  
Author(s):  
Gantayata Gouda ◽  
Balaji Sankar ◽  
Venkat Iyengar ◽  
Jana Soumendu
Keyword(s):  
Experimental Data ◽  
Simulation Model ◽  
Estimation Method ◽  
Critical Parameters ◽  
Aircraft Engines ◽  
Performance Parameters ◽  
Nozzle Throat ◽  
Design Modification ◽  
Turbine Engine ◽  
Jet Nozzle

Modifications to the critical parameters, such as the exhaust nozzle area, are sometimes done during maintenance of aircraft engines. These modifications are done either to increase the design thrust or to compensate for the reduction of thrust due to leakage in the variable area jet nozzle. There is a trade-off between several performance parameters when such critical parameters are changed during maintenance. A tuned aerothermodynamic simulation model that agrees well with the experimental data from the original engine is required to study the effect of these changes. In the present work, a multipoint map scaling approach and a parameter estimation method are used to develop a simulation model that agrees well with the experimental data from the original turbojet engine. The design modifications are then incorporated in the model, and the effect of the modification on the various performance parameters is studied. The effect of leakage in the nozzle flaps and the corresponding reduction required in the nozzle throat area are calculated. It is shown that the tuned model developed with experimental testbed data enables the identification of ancillary effects of a change in a design parameter, such as the nozzle throat area.

scholarly journals Estimation of Performance Parameters of Turbine Engine Components Using Experimental Data in Parametric Uncertainty Conditions

2019 ◽  
Author(s):  
Olexandr Khustochka ◽  
Sergiy Yepifanov ◽  
Roman Zelenskyi ◽  
Radoslaw Przysowa
Keyword(s):  
Experimental Data ◽  
Path Analysis ◽  
Measurement Errors ◽  
Dynamic Models ◽  
A Priori ◽  
Estimation Method ◽  
Parametric Uncertainty ◽  
Performance Parameters ◽  
Turbine Engine ◽  
Engine Components

Gas Path Analysis and matching turbine engine models to experimental data are inverse problems of mathematical modelling which are characterized by parametric uncertainty. This results from the fact that the number of measured parameters is significantly lower than the number of components’ performance parameters needed to describe the real engine. In these conditions, even small measurement errors can result in a high variation of results, and obtained efficiency, loss factors etc. can appear out of the physical range. The current methods of engine model identification have developed considerably to provide stable, precise and physically adequate solutions. Presented in this work is an estimation method of engine components’ parameters based on multi-criteria identification which provides stable estimations of parameters and their confidence intervals with the known measurement errors. A priori information about the engine, its parameters and performance is used directly in the regularised identification procedure. The mathematical basis for this approach is the fuzzy sets theory. Forming objective functions and scalar convolutions synthesis of these functions is used to estimate gas-path components’ parameters. A comparison of the proposed approach with traditional methods showed that its main advantage is high stability of estimation in the parametric uncertainty conditions. Regularization reduces scattering, excludes incorrect solutions which do not correspond to a priori assumptions, and also helps to implement the Gas Path Analysis at the limited number of measured parameters. The method can be used for matching thermodynamic models to experimental data, Gas Path Analysis and also adapting dynamic models for the needs of the engine control system.

Qualification of an Afterburner Thrust Augmentation System for an Aero Gas Turbine Engine

2010 ◽  
Author(s):  
R. K. Mishra
Keyword(s):  
Combustion Efficiency ◽  
Vital Role ◽  
Point Of View ◽  
Performance Parameters ◽  
Considerable Time ◽  
Turbine Engine ◽  
Aero Engine ◽  
Jet Nozzle ◽  
And Performance ◽  
Load Conditions

Qualification of afterburner thrust augmentation system in stand-alone mode prior to its flight trials plays a vital role in aero engine application. A full-scale afterburner system was studied to demonstrate its performance parameters such as pressure loss, combustion efficiency, liner temperature at full and part load conditions. Light-off characteristics at different altitude-flight Mach combination were also established. The afterburner system also was activated for considerable time to validate its integrity and performance. The paper presents the various tests carried out on the afterburner and their results. The paper also highlights the jet nozzle matching at various throttle position and studies on combustion instability from qualification point of view. Satisfactory demonstration of performance of the afterburner without encountering screech or buzz over the operating range qualifies the system for its application in the aero engine for limited operation.

scholarly journals Estimation of performance parameters of turbine engine components using experimental data in parametric uncertainty conditions

2019 ◽  
Vol 304 ◽  
pp. 03003
Author(s):  
Olexandr Khustochka ◽  
Sergey Chernysh ◽  
Sergiy Yepifanov ◽  
Mykhaylo Ugryumov ◽  
Radoslaw Przysowa
Keyword(s):  
Experimental Data ◽  
Path Analysis ◽  
Measurement Errors ◽  
A Priori ◽  
Parametric Uncertainty ◽  
Performance Parameters ◽  
A Priori Information ◽  
Turbine Engine ◽  
Priori Information ◽  
Engine Components

Gas Path Analysis and matching turbine engine models to experimental data are inverse problems of mathematical modelling which are characterized by parametric uncertainty. It results from the fact that the number of measured parameters is significantly less than the number of components’ performance parameters needed to describe the real engine. Inthese conditions, even small measurement errors can result in a high variation of results, and obtained efficiency, lossfactors etc. can appear out of the physical range. The paper presents new method for setting a priori information about the engine and its performance in view of fuzzy sets, forming objective functions and scalar convolutions synthesis of these functions to estimate gas-path components’ parameters. The comparison of the proposed approach with traditional methods showed that its main advantage is high stability of estimation in the parametric uncertainty conditions. It reduces scattering, excludes incorrect solutions which do not correspond to a priori assumptions, and also helps to implement the Gas Path Analysis at the limited number of measured parameters.

Configuration Pump Performance Test System Design Based on Kingview

2011 ◽  
Vol 121-126 ◽  
pp. 3195-3199
Author(s):  
Li Feng Yang ◽  
Jun Yuan ◽  
Wei Na Liu ◽  
Xiu Ming Nie ◽  
Xue Liang Pei
Keyword(s):  
Experimental Data ◽  
Data Processing ◽  
System Design ◽  
Centrifugal Pump ◽  
Performance Test ◽  
Test System ◽  
Performance Parameters ◽  
Time Data ◽  
Pump Performance ◽  
Real Time Data

Use Kingview to acquire and display the centrifugal pump performance parameters for the real-time data, and will stored the collected experimental data in Access databases, using VB database read, and drawing function for the data processing and rendering performance parameters of relationship curves.

A Highly Robust Thrust Estimation Method with Dissimilar Redundancy Framework for Gas Turbine Engine

2021 ◽  
Author(s):  
Hang Zhao ◽  
Zengbu Liao ◽  
Jinxin Liu ◽  
Ming Li ◽  
Wei Liu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Estimation Method ◽  
Gas Turbine Engine ◽  
Turbine Engine

Differential coding scheme based FSO channel for optical coherent DP-16 QAM transceiver systems

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shabana Urooj ◽  
Norah Muhammad Alwadai ◽  
Vishal Sorathiya ◽  
Sunil Lavadiya ◽  
Juveriya Parmar ◽  
...  
Keyword(s):  
Simulation Model ◽  
Channel Model ◽  
Optical Signal ◽  
Performance Parameters ◽  
Free Space Optical ◽  
Simulation Performance ◽  
Coding Scheme ◽  
Simulation Results ◽  
Systems Simulation ◽  
Differential Coding

Abstract This article has indicated optical coherent differential polarization (DP) 16 quadrature amplitude modulation (QAM) transceiver systems with free-space optical (FSO) channel in the presence of differential coding scheme. The optical coherent DP 16-QAM receiver executes the reverse process conversion of the optical signal into an electrical one that is detected to the users. The proposed optical coherent DP-16 QAM transceiver systems based FSO channel model with differential coding has been presented and compared with the previous model. However, the simulation results have confidence realization about the superiority of the proposed simulation model. Hence the proposed optical coherent DP-16 QAM transceiver systems simulation model with differential coding is verified and validated the enhancement performance based on simulation performance parameters.

scholarly journals Determination of the Firing Pin Critical Velocity and the Critical Power in the Percussive Initiation of Primer Caps

2016 ◽  
Vol 7 (4) ◽  
pp. 33-66
Author(s):  
Andrzej FARYŃSKI ◽  
Andrzej DŁUGOŁĘCKI ◽  
Jarosław DĘBIŃSKI ◽  
Łukasz SŁONKIEWICZ
Keyword(s):  
Experimental Data ◽  
Critical Velocity ◽  
Hot Spot ◽  
Pulse Power ◽  
Critical Parameters ◽  
Simplified Model ◽  
Initiation Mechanism ◽  
The Mean ◽  
Institute Of Technology ◽  
Explosive Reaction

This work involved testing of the probability of initiating a KWM-3 type of primer cap as a function of the firing pin velocity upon impact. The tested firing pin was accelerated to the required velocity by a falling mass. The measurements under this work were made with a measurement system and methodologies developed at Air Force Institute of Technology (AFIT) in Warsaw (Poland). The percussive pulse velocity and power was altered by modifying the percussive mass to keep the initiating pulse energy constant at two levels: Ewe = 272 mJ and 343 mJ. The firing pin velocity values estimated by experimental data to bring a 50% probability of percussive primer cap initiation were within the interval vi50% = 0.34÷0.51 m/s. It was found that the mean primer cap ignition delay rose from approx. 0.7 ms at a percussion velocity of 1.5 m/s to 6 ms at 0.17 m/s. The experimental data suggest the values of Ewe x vi50% = 0.136. A simplified model was proposed for the deformation of the primer cap base and compressed pyrotechnical mixture shape. The model served to determine the approximate time trend for the penetration of the primer cap by the firing pin, including velocity, power and emitted energy, by assuming a complete energy transfer from the percussive mass to the primer cap. The mean initiating pulse power calculated from the model at the vi50% interval was Pavg = 120÷180 W, whereas the maximum initiating pulse power was Pmax = 170÷250 W. The calculated time values for firing pin penetration were very close to the aforementioned primer cap ignition delays at the respective velocity and percussive mass values. This indirectly indicates nearly complete energy transmission from the percussive masses to the primer caps. A location was identified within the compressed pyrotechnical mixture shape volume which could form the hot spot for initiation of the explosive reaction. Based on the calculation results using the simplified model, and assuming that the energy and diffusive heat flux output to and from the explosive reaction initiation hot spot were equivalent, the expression of Ewe x vi50% derived from the result was approx. 0.18. This means that the two critical parameters of primer cap initiation: (i) velocity, which can be identified with vi50% (and the respective power) and (ii) Ewe50%, i.e. the energy threshold below which the probability of primer cap initiation is less than 0.5, are interrelated. Aside from the initiation mechanism proposed and applied to calculate the firing pin critical velocity, this work discusses several other initiation mechanisms, all of which were ruled out during the testing process.

scholarly journals Investigation of a parameter estimation method for contaminant transport in aquifers

2001 ◽  
Vol 3 (4) ◽  
pp. 203-213 ◽  
Author(s):  
Channa Rajanayaka ◽  
Don Kulasiri
Keyword(s):  
Experimental Data ◽  
Hydraulic Conductivity ◽  
Contaminant Transport ◽  
Dispersion Coefficient ◽  
Estimation Method ◽  
Longitudinal Dispersion ◽  
Longitudinal Dispersion Coefficient ◽  
System Noise ◽  
Estimated Parameters ◽  
Comparison Of The Results

Real world groundwater aquifers are heterogeneous and system variables are not uniformly distributed across the aquifer. Therefore, in the modelling of the contaminant transport, we need to consider the uncertainty associated with the system. Unny presented a method to describe the system by stochastic differential equations and then to estimate the parameters by using the maximum likelihood approach. In this paper, this method was explored by using artificial and experimental data. First a set of data was used to explore the effect of system noise on estimated parameters. The experimental data was used to compare the estimated parameters with the calibrated results. Estimates obtained from artificial data show reasonable accuracy when the system noise is present. The accuracy of the estimates has an inverse relationship to the noise. Hydraulic conductivity estimates in a one-parameter situation give more accurate results than in a two-parameter situation. The effect of the noise on estimates of the longitudinal dispersion coefficient is less compared to the effect on hydraulic conductivity estimates. Comparison of the results of the experimental dataset shows that estimates of the longitudinal dispersion coefficient are similar to the aquifer calibrated results. However, hydraulic conductivity does not provide a similar level of accuracy. The main advantage of the estimation method presented here is its direct dependence on field observations in the presence of reasonably large noise levels.

Commutation Loss in Hydrostatic Pumps and Motors

2021 ◽  
Author(s):  
Robin Mommers ◽  
Peter Achten ◽  
Jasper Achten ◽  
Jeroen Potma
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Simulation Model ◽  
Operating Conditions ◽  
Chamber Pressure ◽  
Working Mechanism ◽  
Working Chamber ◽  
Lumped Parameter ◽  
Long Time ◽  
Pressure Changes

Abstract In mobile hydraulic applications, more efficient machinery generally translates to smaller batteries or less diesel consumption, and smaller cooling solutions. A key part of such systems are hydrostatic pumps and motors. While these devices have been around for a long time, some of the causes of energy loss in pump and motors are still not properly defined. This paper focuses on one of the causes of energy loss in pumps and motors, by identifying the energy loss as a result of the process of commutation. By nature, all hydrostatic pumps and motors have some form of commutation: the transition from the supply port to the discharge port of the machine (and vice versa). During commutation, the connection between the working chamber and the ports is temporarily closed. The chamber pressure changes by compression or decompression that is the result of the rotation of the working mechanism. Ideally, the connection to one of the ports is opened once the chamber pressure equals the port pressure. When the connection is opened too early or too late, energy is lost. This paper describes a method to predict the commutation loss using a lumped parameter simulation model. To verify these predictions, experimental data of a floating cup pump was compared to the calculated values, which show a decent match. Furthermore, the results show that, depending on the operating conditions, up to 50% of all losses in this pump are caused by improper commutation.

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