Influence of secondary flow on aero-engine performance

2013 ◽  
Author(s):  
Xiao-bo Zhang ◽  
Zhan-xue Wang ◽  
Zeng-wen Liu
Keyword(s):  
Secondary Flow ◽  
Engine Performance ◽  
Aero Engine

Probabilistic Analysis of a Turbofan Secondary Flow System

2004 ◽  
Author(s):  
David Cloud ◽  
Ethan Stearns
Keyword(s):  
Secondary Flow ◽  
Probabilistic Analysis ◽  
Flow System ◽  
Engine Performance ◽  
Root Cause ◽  
Engine Design ◽  
Bearing Loads ◽  
Input Variables ◽  
Time Required ◽  
Individual Input

This paper documents a probabilistic analysis of the secondary flow system in a modern commercial turbofan engine. The purpose of this analysis is to investigate the variability in the high and low rotor bearing loads and total secondary flow due to the inherent uncertainty in manufacturing processes and engine performance. In addition to quantifying the variability in bearing load and secondary flow, the sensitivity of the parameters to individual input variables is determined. The system was found to behave linearly, resulting in negligible mean shifts due to input variation. The importance of correlation among the performance parameters will be addressed, as well as the effects of different correlations. Methods used to reduce the time required for the analysis will also be discussed. This type of analysis has many applications in cost reduction, engine design, optimization, and root cause analysis that will be covered in this paper.

Aero Engine Performance Evaluation During Missile Firing Test

2017 ◽  
Author(s):  
Sajath Kumar Manoharan ◽  
Kasram Santhosh ◽  
Mahesh P. Padwale ◽  
G. P. Ravishankar
Keyword(s):  
Performance Evaluation ◽  
Engine Performance ◽  
Flight Testing ◽  
Flow Disturbance ◽  
Fighter Aircraft ◽  
Firing Test ◽  
Aero Engine ◽  
Temperature Ramps ◽  
Air Intake ◽  
Model Engine

Evaluation of engine performance during armament firing in fighter aircraft is a vital qualification aspect for airframe engine integration. Ingestion of missile’s efflux into air intake results in rapid increase of engine inlet temperatures (temperature ramps) which cause flow disturbance to the compressor. Temperature distortion caused due to armament firing and its effect on compressor stability during flight testing is evaluated. Accordingly mitigation actions are recommended for stall/surge free operations. Distortion descriptors are assessed using simulation model (engine performance program) and results compared with engine distortion limits.

scholarly journals Effect of jet-A1 emulsified fuel on aero-engine performance and emissions

2019 ◽  
Author(s):  
Maria Grazia De Giorgi ◽  
Giuseppe Ciccarella ◽  
Antonio Ficarella ◽  
Donato Fontanarosa ◽  
Elisa Pescini
Keyword(s):  
Engine Performance ◽  
Emulsified Fuel ◽  
Aero Engine ◽  
Performance And Emissions ◽  
Engine Performance And Emissions

Non-Linear Aeromechanical Behaviour of Axial Core Compressor Stator Vanes

2007 ◽  
Author(s):  
Caetano Peng
Keyword(s):  
Integrated Design ◽  
Engine Performance ◽  
Forced Response ◽  
Design Tools ◽  
Virtual Testing ◽  
Aero Engine ◽  
Stator Vane ◽  
Recent Developments ◽  
Aero Engines ◽  
Engine Components

This paper highlights some engine non-linearities that can affect both performance and robustness of aero engines. It pays particular attention to non-linearities generated at the stator vane contact end joints. These non-linearities resulting from friction contact joints affect the vane modeshapes, damping and forced response. This work proposes upper and lower bound solutions based on vane end restraints non-linearities to predict conservative forced response of stator vanes. Some non-linearities such as those caused by mistuning can be beneficial to the component and system. There are also non-linearities that can be detrimental to engine performance, robustness and reliability. Moreover, it proposes and discusses the concept of temporal HCF or CCF lifing method. Recent developments in FE, CFD, mistuning, forced response and probabilistic codes can help to create more integrated design tools that incorporate time-dependent non-linearities in the lifing of aero engine components. Computations performed here demonstrated some level of component virtual testing. These analyses are important component virtual testing that will be gradually extended to whole aero engine virtual testing.

Thermodynamics Cycle Analysis, Pressure Loss and Heat Transfer Assessment of a Recuperative System for Aero Engines

2014 ◽  
Author(s):  
A. Goulas ◽  
S. Donnerhack ◽  
M. Flouros ◽  
D. Misirlis ◽  
Z. Vlahostergios ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Fuel Consumption ◽  
Heat Exchangers ◽  
Engine Performance ◽  
Specific Fuel Consumption ◽  
Hot Gas ◽  
Research Activities ◽  
Aero Engine ◽  
Overall Efficiency ◽  
Aero Engines

Aiming in the direction of designing more efficient aero engines, various concepts have been developed in recent years, among which is the concept of an intercooled and recuperative aero engine. Particularly in the area of recuperation, MTU Aero Engines has been driving research activities in the last decade. This concept is based on the use of a system of heat exchangers mounted inside the hot-gas exhaust nozzle (recuperator). Through the operation of the system of heat exchangers, the heat from the exhaust gas, downstream the LP turbine of the jet engine is driven back to the combustion chamber. Thus, the preheated air enters the engine combustion chamber with increased enthalpy, providing improved combustion and by consequence, increased fuel economy and low-level emissions. If additionally an intercooler is placed between the compressor stages of the aero engine, the compressed air is then cooled by the intercooler thus, less compression work is required to reach the compressor target pressure. In this paper an overall assessment of the system is presented with particular focus on the recuperative system and the heat exchangers mounted into the aero engine’s exhaust nozzle. The herein presented results were based on the combined use of CFD computations, experimental measurements and thermodynamic cycle analysis. They focus on the effects of total pressure losses and heat exchanger efficiency on the aero engine performance especially the engine’s overall efficiency and the specific fuel consumption. More specifically, two different hot-gas exhaust nozzle configurations incorporating modifications in the system of heat exchangers are examined. The results show that significant improvements can be achieved in overall efficiency and specific fuel consumption hence contributing into the reduction of CO2 and NOx emissions. The design of a more sophisticated recuperation system can lead to further improvements in the aero engine efficiency in the reduction of fuel consumption. This work is part of the European funded research program LEMCOTEC (Low Emissions Core engine Technologies).

Application of the Regularization Chaos Prediction Model in Aero-Engine Performance Parameters

2012 ◽  
Vol 424-425 ◽  
pp. 347-351 ◽  
Author(s):  
Yong Sheng Shi ◽  
Jun Jie Yue ◽  
Yun Xue Song
Keyword(s):  
Prediction Model ◽  
Simulation Analysis ◽  
Search Algorithm ◽  
Engine Performance ◽  
Forecasting Model ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Engine Exhaust ◽  
Aero Engine ◽  
Exhaust Gas Temperature

Based on the research of complexity and non-linearity of aero-engine exhaust gas temperature (EGT) system, a regularization chaotic prediction model was proposed to build short time forecasting model of EGT. In this paper, in order to gain the best parameter to improve the accuracy of the forecasting model, a simple search algorithm arithmetic was adopted. The simulation analysis shows that the proposed forecasting model obviously exceeded the traditional chaotic forecasting model on prediction accuracy. Therefore, this arithmetic is efficient and feasible for a short-term prediction of aero-engine exhaust gas temperature

Analysis of vibration from low-rigidity contact in belt grinding of blisk blade

2019 ◽  
Vol 233 (12) ◽  
pp. 2345-2357 ◽  
Author(s):  
Guijian Xiao ◽  
Yun Huang ◽  
Ying Liu ◽  
Quan Li ◽  
Wentao Dai
Keyword(s):  
Process Parameters ◽  
Engine Performance ◽  
Grinding Process ◽  
Feed Speed ◽  
Technological Parameters ◽  
Belt Grinding ◽  
Cross Sectional ◽  
Aero Engine ◽  
The Stability ◽  
Grinding System

A blisk is one of the key parts of an aero-engine, whose surface processing quality directly affects aero-engine performance. Different degrees of vibration occur during the process of new open belt grinding which seriously affect the precision of the dimensions and the surface quality of the entire blade profile. With the aim of addressing this problem, this study constructed a physical model of blisk belt grinding, analysed the low-rigidity characteristics of the grinding system, and researched the vibratory mechanism of the blisk belt grinding system based on a dynamic analysis method. In addition, the factors affecting the stability of the grinding process and the stability conditions of the grinding were considered. Then, the belt grinding process of a blade surface was simulated through a numerical method. The technological parameters were quantified for different conditions of the blisk belt grinding vibration. The optimal combination of process parameters was obtained. Finally, the optimised process parameters were validated experimentally. The research demonstrates that vibration from blisk belt grinding is related to the process parameters as follows, in the order of the greatest influence: the grinding pressure, belt velocity, feed speed, and contact wheel hardness. After optimisation, the cross-sectional profile is 0.031–0.041 mm and the surface roughness is 0.1–0.2 μm; the surface is smoother and has better consistency.

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