Impacts of aero-engine deteriorations on military aircraft mission's effectiveness

2001 ◽  
Vol 105 (1054) ◽  
pp. 685-696 ◽  
Author(s):  
M. Naeem ◽  
R. Singh ◽  
D. Probert
Keyword(s):  
Life Cycle ◽  
Armed Forces ◽  
Life Cycle Costs ◽  
Military Aircraft ◽  
Operational Effectiveness ◽  
Turbine Engine ◽  
Operational Life ◽  
Aero Engine ◽  
Aero Engines ◽  
Economic Developments

Abstract International political and socio-economic developments have led the armed forces of many countries to become more aware of how their increasingly-stringent financial budgets are spent. One major expenditure for military authorities is upon aero-engines, because in-service deterioration in any mechanical device, such as an aircraft's gas-turbine engine, is inevitable. Each deterioration has an adverse effect on the performance and shortens the reliable operational life of the engine, thereby resulting in higher life-cycle costs. For a military aircraft's mission-profiles, the consequences of an aero-engine's deterioration upon the aircraft's operational-effectiveness as well as its fuel consumption and life have been predicted in this project using validated computer-simulations. These help in making wiser management-decisions, so leading to the achievement of improved engine utilisation, lower overall life-cycle costs and optimal mission effectiveness for squadrons of aircraft.

Impacts of low-pressure (LP) compressor’s deterioration of a turbofan engine upon fuel-usage of a military aircraft

2008 ◽  
Vol 112 (1127) ◽  
pp. 33-45 ◽  
Author(s):  
M. Naeem
Keyword(s):  
Low Pressure ◽  
Operating Point ◽  
Life Cycle Costs ◽  
Military Aircraft ◽  
Turbine Engine ◽  
Fuel Flow ◽  
Military Aviation ◽  
Aero Engine ◽  
Design And Manufacture ◽  
Mission Profile

AbstractSome in-service deterioration in any mechanical device, such as an aircraft’s gas-turbine engine, is inevitable. However, its extent and rate depend upon the qualities of design and manufacture, as well as on the maintenance/repair practices followed by the users. Deterioration of an engine normally results in the engine seeking a different steady operating-point relative to that for an engine without any deterioration. The variation in engine’s steady operating point leads to changes in the specific fuel consumption (SFC) and/or fuel flow (FF). Any rise in SFC and/or FF and thereby the increased quantity of fuel required is of prime importance in military aviation.For a military aircraft’s mission-profiles (consisting of several flight-segments), using a bespoke computer simulations, the consequences of low-pressure compressor’s deterioration of an aeroengine upon the weight of the fuel that has to be carried and consumed are predicted. This will help in making wiser management decisions (such as whether to remove an aero-engine from the aircraft for maintenance or to continue using it with some changes in aircraft’s mission profile). Hence improved engine utilization can be achieved, so resulting in lower overall life-cycle costs.

scholarly journals Analysis of the implementation of the budget and defence planning in the Ministry Defence of Ukraine and the Armed Forces of Ukraine in the context of weapons and military equipment

2019 ◽  
Vol 9 (5) ◽  
pp. 174-189
Author(s):  
Pavlo Parkhomenko ◽  
Michael Lavruk ◽  
Ivan Tkach
Keyword(s):  
Life Cycle ◽  
Armed Forces ◽  
Development Planning ◽  
Life Cycle Costs ◽  
Foreign Experience ◽  
Military Equipment ◽  
Domestic Practice ◽  
Technical And Economic Indicators ◽  
Research Recommendations ◽  
Defense Planning

The article discusses the main approaches to the organization of budgetary and defense planning in the Ministry of Defense of Ukraine and the Armed Forces of Ukraine in the context of the development of weapons and military equipment. The study focuses on the feasibility and necessity of bringing budgetary and defense planning to the best world practices applied by the world's leading countries, including on arms development planning, taking into account the life-cycle costs of weapons and military equipment. The generalized and substantiated views in the scientific and practical environment in Ukraine on the ways and problematic issues of introducing foreign experience of planning arms development into domestic practice. According to the results of the research, recommendations were made for the formation of technical and economic indicators of the life cycle of weapons and military equipment, which take place in the scientific and practical environment of customers and contractors of weapons.

Structural Integrity Validation for Rotor Discs and Shafts in Aero-Engines

2013 ◽  
Author(s):  
Sanju Kumar ◽  
Rashmi Rao ◽  
Rajeevalochanam B. Ananthappa ◽  
Venkateshwarlu Mogullapally
Keyword(s):  
Gas Turbine ◽  
Material Characterization ◽  
Structural Integrity ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Aero Engine ◽  
Aero Engines ◽  
Integrity Analysis ◽  
Structural Validation ◽  
Validation Testing

Design of rotating structures in military gas turbine engine is complex and arduous. The aero engine main discs and shafts are designed to achieve maximum operating capabilities under severe loads. The potential failures of primary rotating parts are extremely catastrophic. Hence, ignoring structural integrity aspects, results in engine failures, which is a major concern and motivation for the present paper. In this paper structural integrity analysis using CAE are discussed for rotating components and various structural validation testing employed are highlighted. The structural integrity study carried out conforms to stipulation of MIL 5007 D/E. The validation carried out includes material characterization, cyclic spin tests, overspeed and burst speed tests. This paper also emphasizes structural integrity studies on engine main shafts, for buckling, maneuvers and blade-off loads.

Life Cycle Cost Analysis of a Novel Cooling and Power Gas Turbine Engine

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Vaibhav Malhotra ◽  
W. E. Lear ◽  
J. R. Khan ◽  
S. A. Sherif
Keyword(s):  
High Pressure ◽  
Life Cycle ◽  
Cost Analysis ◽  
Life Cycle Cost ◽  
Cost Savings ◽  
Life Cycle Costs ◽  
Life Cycle Cost Analysis ◽  
Absorption Refrigeration ◽  
Power Capacity ◽  
Turbine Engine

A life cycle cost analysis was performed to compare life cycle costs of a novel gas turbine engine to those of a conventional microturbine with similar power capacity. This engine, called the high-pressure regenerative turbine engine (HPRTE), operates on a pressurized semiclosed cycle and is integrated with a vapor absorption refrigeration system. The HPRTE uses heat from its exhaust gases to power the absorption refrigeration unit, which cools the high-pressure compressor inlet of the HPRTE to below ambient temperatures and also produces some external refrigeration. The life cycle cost analysis procedure is based on principles laid out in the Federal Energy Management Program. The influence of different design and economic parameters on the life cycle costs of both technologies is analyzed. The results of this analysis are expressed in terms of the cost ratios of the two technologies. The pressurized nature of the HPRTE leads to compact components resulting in significant savings in equipment cost versus those of a microturbine. Revenue obtained from external refrigeration offsets some of the fuel costs for the HPRTE, thus proving to be a major contributor in cost savings for the HPRTE. For the base case of a high-pressure turbine (HPT) inlet temperature of 1373 K and an exit temperature of 1073 K, the HPRTE showed life cycle cost savings of 7% over a microturbine with a similar power capacity.

Experimental Testing of Carbon Brush Seals for Aero Engines Bearing Chambers

2014 ◽  
Author(s):  
Bilal Outirba ◽  
Patrick Hendrick
Keyword(s):  
Experimental Testing ◽  
Secondary Flows ◽  
Engine Oil ◽  
Oil Consumption ◽  
Test Rig ◽  
Turbine Engine ◽  
Aero Engine ◽  
Recent Developments ◽  
Brush Seals ◽  
Aero Engines

This paper provides the first step in sizing carbon brush seals for aero-engine oil bearing chambers applications. Recent developments in the aeronautic domain focus strongly on the reduction of aero-engine specific oil consumption. For instance, optimizing the civil aircraft gas turbine engine lubrication oil system is considered as one of the main targets in this research. Specifically, brush seals have shown tremendous leakage performance in sealing secondary flows compared to classic labyrinth seals over the last few decades. Therefore, an attractive idea is to extent their utilization to oil bearing chamber applications. To perform the experimental part of the study, a test rig has recently been built at ULB. This test rig will be described in this paper. A parametrical study has been performed in stationary conditions, and at very low rotation speed. A particular attention was given to the air consumption and the torque friction losses. Finally, a test simulating the effects of a rotor excursion on the brush seal performance has been made.

Life Cycle Cost Analysis of a Novel Cooling and Power Gas Turbine Engine

2005 ◽  
Author(s):  
Vaibhav Malhotra ◽  
W. E. Lear ◽  
J. R. Khan ◽  
S. A. Sherif
Keyword(s):  
High Pressure ◽  
Life Cycle ◽  
Cost Analysis ◽  
Life Cycle Cost ◽  
Cost Savings ◽  
Life Cycle Costs ◽  
Life Cycle Cost Analysis ◽  
Absorption Refrigeration ◽  
Power Capacity ◽  
Turbine Engine

A Life cycle cost analysis (LCCA) was performed to compare life cycle costs of a novel gas turbine engine to that of a conventional microturbine with similar power capacity. This engine, called the High Pressure Regenerative Turbine Engine (HPRTE) operates on a pressurized semiclosed cycle and is integrated with a Vapor Absorption Refrigeration System (VARS). The HPRTE uses heat from its exhaust gases to power the absorption refrigeration unit which cools the high-pressure compressor inlet of the HPRTE to below ambient temperatures and also produces some external refrigeration. The life cycle cost analysis procedure is based on principles laid out in the Federal Energy Management Program (FEMP). The influence of different design and economic parameters on the life cycle costs of both technologies is analyzed. The results of this analysis are expressed in terms of the cost ratios of the two technologies. The pressurized nature of the HPRTE leads to compact components resulting in significant savings in equipment cost versus those of a microturbine. Revenue obtained from external refrigeration offsets some of the fuel costs for the HPRTE, thus proving to be a major contributor in cost savings for the HPRTE. For the base case of a high-pressure turbine (HPT) inlet temperature of 1373 K and an exit temperature of 1073 K, the HPRTE showed life cycle cost savings of 7% over a microturbine with a similar power capacity.

Impacts of low-pressure (LP) compressor’s deterioration upon an aero-engine’s high-pressure (HP) turbine blade’s life consumption

2006 ◽  
Vol 110 (1106) ◽  
pp. 227-238 ◽  
Author(s):  
M. Naeem
Keyword(s):  
High Pressure ◽  
Low Pressure ◽  
Life Cycle Costs ◽  
Military Aircraft ◽  
Mechanical Device ◽  
Operating Characteristics ◽  
Performance Simulation ◽  
Computer Performance ◽  
Aero Engine ◽  
Life Consumption

AbstractSome in-service deterioration in any mechanical device, such as an aero-engine, is inevitable. As a result of experiencing a deterioration of efficiency and/or mass flow, an aero-engine will automatically adjust to a different set of operating characteristics; thereby frequently resulting in changes of rpm and/or turbine entry temperature in order to provide the same thrust. Rises in the turbine entry-temperatures and the high-pressure turbine’s rotational speed result in greater rates of creep and fatigue damage being incurred by the hot-end components and thereby higher engine’s life cycle costs. Possessing a better knowledge of the effects of engine deterioration upon the aircraft’s performance, as well as fuel and life usages, helps the users to take wiser management decisions and hence achieve improved engine utilisation. For a military aircraft, using a computer performance simulation, the consequences of low-pressure (LP) compressor’s deterioration upon an aero-engine high-pressure (HP) turbine blade’s life-consumption have been predicted.

scholarly journals OPTIMIZATION OF AERO ENGINE UTILIZATION THROUGH IMPROVED ESTIMATION OF REMAINING USEFUL LIFE (RUL) OF ON CONDITION (OC) PARTS

2020 ◽  
Author(s):  
Kotha Vidyasagar
Keyword(s):  
Gas Turbine ◽  
Remaining Useful Life ◽  
Accurate Estimation ◽  
Physical Problems ◽  
Safety Margins ◽  
Operational Life ◽  
Replacement Model ◽  
Aero Engine ◽  
Useful Life ◽  
Aero Engines

Gas Turbine Operators and Maintainers face the challenge of increasing the operational life, availability, and reliability of Aero Engine during the operations amid the advancements in the technology for the speed, Power, SFC, and Comfort which led to closing in the safety margins and increasing in the failure rate of Aero Engines, and low serviceability of aero engines due to the rapid increase in demand and expansion of the aircraft fleet by the various airlines for various reasons which led to increase in downtime and lead time of serviceability of Aero Engines. This study focuses on the inherent Aero Engine deterioration caused due to various Gas Turbine Faults or Physical Problems and how Performance, Trend, and Systems Monitoring contain this deterioration and contribute to the optimization of aero engine utilization. The purpose of this paper is to present the importance of accurate estimation of Remaining Useful Life (RUL) of On Condition (OC) Parts and how it optimizes aero engine life. The benefits associated with the introduction of a novel estimation of RUL of OC Parts are also presented. A Standardized Replacement Model (SRM), which improves the estimation of RUL of OC Parts, is proposed for optimization of Aero Engine Utilization

A Logistics Model of Total Life Cycle of Mechanical Products

2012 ◽  
Vol 248 ◽  
pp. 402-407 ◽  
Author(s):  
Liang He ◽  
Wan Lin Guo
Keyword(s):  
Life Cycle ◽  
Life Cycle Analysis ◽  
Production Capacity ◽  
Stable Production ◽  
Equivalent Quantity ◽  
Aero Engine ◽  
Mechanical Products ◽  
Aero Engines ◽  
Total Life ◽  
Production Resources

A kind of processing strategy of total life cycle of mechanical products was designed. A logistics model of total life cycle of mechanical products was established based on eight typical states of life cycle of mechanical products. The logistics analysis of total life cycle of a sort of aero-engine was carried out by using the model. The dynamic equivalent quantity of the aero-engines in different states of life cycle was obtained when times changed from the products were first put into production to the time when stable production capacity was reached. The model can also be used to predict logistics of other products rapidly. The results give references for production departments or enterprises which use life cycle methods to configure their production resources effectively and optimize production processes, and also provide a basis for further analysis of total life cycle analysis such as economic and environmental assessment.

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