scholarly journals Failure Analysis of the Pin Bore of the Combined Piston for the Aero Engine

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Zhongjian Pan ◽  
Lei Guo
Keyword(s):  
Weight Ratio ◽  
Thermomechanical Coupling ◽  
Inertia Force ◽  
Test Results ◽  
Piston Head ◽  
Acceptable Range ◽  
Piston Crown ◽  
Aero Engine ◽  
Original Scheme ◽  
Engine Power

The combined piston can be used in an aero piston heavy fuel engine because of its light weight, so as to reduce the reciprocating inertia force and improve the engine power-weight ratio. However, the pin bore of the combined piston is prone to deform leading to the failure of the piston. Based on the structure of the piston, the stress of the piston under thermomechanical coupling is analyzed, the temperature field of the piston is determined by experiments, and the deformation rule of the piston pin bore under the thermomechanical coupling is summarized. A design scheme is proposed to change the position of the thread connection between the piston crown and the piston head. Under the same conditions, the deformation of the piston pin bore of the original scheme and the new scheme is analyzed. The results show that together with the changing of the connection thread between the piston crown and the piston head, the deformation of the piston pin bore decreases by 60 μm and the deformation of the piston pin bore is controlled. The test results show that the deformation of the pin bore is within the acceptable range, which proves the effectiveness of the improved scheme.

An improved dynamic load-strength interference model for the reliability analysis of aero-engine rotor blade system

2020 ◽  
pp. 095441002097289
Author(s):  
Bingfeng Zhao ◽  
Liyang Xie ◽  
Yu Zhang ◽  
Jungang Ren ◽  
Xin Bai ◽  
...  
Keyword(s):  
Reliability Analysis ◽  
Dynamic Load ◽  
Rotor Blade ◽  
Engineering Application ◽  
Weight Ratio ◽  
System Component ◽  
Aero Engine ◽  
Blade System ◽  
Improved Model ◽  
Engine Rotor

As the power source of an aircraft, aero-engine tends to meet many rigorous requirements for high thrust-weight ratio and reliability with the continuous improvement of aero-engine performance. In this paper, based on the order statistics and stochastic process theory, an improved dynamic load-strength interference (LSI) model was proposed for the reliability analysis of aero-engine rotor blade system, with strength degradation and catastrophic failure involved. In presented model, the “unconventional active” characteristic of rotor blade system, changeable functioning relationships and system-component configurations, was fully considered, which is necessary for both theoretical analysis and engineering application. In addition, to reduce the computation cost, a simplified form of the improved LSI model was also built for convenience of engineering application. To verify the effectiveness of the improved model, reliability of turbojet 7 engine rotor blade system was calculated by the improved LSI model based on the results of static finite element analysis. Compared with the traditional LSI model, the result showed that there were significant differences between the calculation results of the two models, in which the improved model was more appropriate to the practical condition.

Investigations on performance of diesel engine by varying injection timings with design modification on piston crown

2018 ◽  
Vol 15 (5) ◽  
pp. 562-566
Author(s):  
Vijaya K. ◽  
Shailesh Palaparty ◽  
Raghavan Srinivasa ◽  
Ravi Kumar Puli
Keyword(s):  
Diesel Engine ◽  
Injection Pressure ◽  
Combustible Mixture ◽  
Injection Timing ◽  
Connecting Rod ◽  
Design Modification ◽  
Content Type ◽  
Piston Head ◽  
Piston Crown ◽  
Fuel Vaporization

Purpose Investigations are carried out with the aim of improving performance of a diesel engine with the design modification on piston crown to stimulate the uniform combustion by inducing turbulence in the incoming charge. Design/methodology/approach A stirrer is introduced at the top of the piston so as to inculcate more turbulence to the incoming charge by improving the rate of fuel vaporization. Whirling motion is created in the combustible mixture by providing rotating blades on the cavity/bowl of the reciprocating piston head. By putting a simple link mechanism, the oscillatory motion of connecting rod will rotate the blade by an angle of 60°. Findings The investigations are carried out with and without swirl piston at 17.5 compression ratio and 200 bar injection pressure by varying injection timings. Originality/value Finally, the result shows that by using the modified piston, nearly 3 per cent of efficiency increased and 31 per cent of NOx emissions are reduced compared to that of a normal piston with 80 per cent load at standard injection timing.

Micro Machining of Nonconductive Al2O3 Ceramic on Developed TW-ECSM Setup

2012 ◽  
pp. 167-177
Author(s):  
Alakesh Manna ◽  
Amandeep Kundal
Keyword(s):  
Weight Ratio ◽  
High Hardness ◽  
High Strength ◽  
Ceramic Materials ◽  
Actual Condition ◽  
Test Results ◽  
Machining Performance ◽  
Machining Processes ◽  
Al2o3 Ceramic ◽  
Advanced Ceramic

Advanced ceramic materials are gradually becoming very important for their superior properties such as high hardness, wear resistance, chemical resistance, and high strength to weight ratio. But machining of advanced ceramic like Al2O3-ceramics is very difficult by any well known and common machining processes. Normally, cleavages and triangular fractures generate when machining of these materials is done by traditional machining methods. It is essential to develop an efficient and accurate machining method for processing advanced ceramic materials. For effective machining of Al2O3-ceramics, a traveling wire electrochemical spark machining (TW-ECSM) setup has been developed. The developed TW-ECSM setup has been utilized to machine Al2O3 ceramic materials and subsequently test results are utilized to analyze the machining performance characteristic. Different SEM photographs show the actual condition of the micro machined surfaces. The practical research analysis and test results on the machining of Al2O3 ceramics by developed TWECSM setup will provide a new guideline to the researchers and manufacturing engineers.

Micro Machining of Nonconductive Al2O3 Ceramic on Developed TW-ECSM Setup

2011 ◽  
Vol 1 (2) ◽  
pp. 46-55
Author(s):  
Alakesh Manna ◽  
Amandeep Kundal
Keyword(s):  
Weight Ratio ◽  
High Hardness ◽  
High Strength ◽  
Ceramic Materials ◽  
Actual Condition ◽  
Test Results ◽  
Machining Performance ◽  
Machining Processes ◽  
Al2o3 Ceramic ◽  
Advanced Ceramic

Advanced ceramic materials are gradually becoming very important for their superior properties such as high hardness, wear resistance, chemical resistance, and high strength to weight ratio. But machining of advanced ceramic like Al2O3-ceramics is very difficult by any well known and common machining processes. Normally, cleavages and triangular fractures generate when machining of these materials is done by traditional machining methods. It is essential to develop an efficient and accurate machining method for processing advanced ceramic materials. For effective machining of Al2O3-ceramics, a traveling wire electrochemical spark machining (TW-ECSM) setup has been developed. The developed TW-ECSM setup has been utilized to machine Al2O3 ceramic materials and subsequently test results are utilized to analyze the machining performance characteristic. Different SEM photographs show the actual condition of the micro machined surfaces. The practical research analysis and test results on the machining of Al2O3 ceramics by developed TWECSM setup will provide a new guideline to the researchers and manufacturing engineers.

Development of Compact Damper Bearing

2005 ◽  
Author(s):  
Hiroshi Kanki ◽  
Yosichika Sato ◽  
Takayuki Ueshima
Keyword(s):  
Rotating Machinery ◽  
Rolling Element Bearing ◽  
Squeeze Film ◽  
Test Results ◽  
Thin Ring ◽  
Compact Size ◽  
Standard Design ◽  
Rolling Element ◽  
Aero Engine ◽  
Element Bearing

The squeeze film damper bearings have been successfully applied for important rotating machinery such as aero engine, high pressure centrifugal compressors[1] and steam turbine[2]. This paper proposes the expansion of application of the damper bearing for small and medium sized rotating machinery. The new damper has a compact size that enable standard design combined with rolling element bearing. A new design of the damper is presented. The new design consists of thin ring and special patterned wire cut grooves. The design analysis and experimental study are presented. The dynamic tests were carried out for this model damper, one is no side seal and the other is with side seals in both ends. Test results showed the sufficient damping effect for actual applications.

Minimizing Sampling Loss in Trace Gas Emission Measurements for Aircraft Engines by Using a Chemical Quick-Quench Probe

2010 ◽  
Author(s):  
Elena de la Rosa Blanco ◽  
Jay Peck ◽  
Richard C. Miake-Lye ◽  
Frank B. Hills ◽  
Ezra C. Wood ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Aircraft Engine ◽  
Trace Gas ◽  
Test Results ◽  
University Of Tennessee ◽  
Quench Probe ◽  
Gas Sampling ◽  
Helium Dilution ◽  
The University ◽  
Engine Power

This paper describes the development and testing of a gas sampling probe that quenches chemical reactions by using supersonic expansion and helium dilution. Gas sampling probes are required for accurate measurement of exhaust emissions species, which is critical to determine the performance of an aircraft engine. The probe was designed through rounds of computational modeling and laboratory testing, and was subsequently manufactured and then tested at the University of Tennessee Space Institute (UTSI) behind a General Electric J85 turbojet engine at different power settings: idle, maximum military and afterburning. The experimental test results demonstrated that the Chemical Quick-Quench (CQQ) probe suppressed the oxidation of carbon monoxide (CO) inside the probe system and preserved more CO at afterburning conditions. In addition, the CQQ probe prevented hydrocarbons from being partially-oxidized to form CO at idle powers, and measured higher hydrocarbons and lower CO emission compared to a conventional probe at that low power condition. The CQQ probe also suppressed nitrogen dioxide (NO2) to nitric oxide (NO) conversion through all engine power settings. These data strongly support the conclusion that the CQQ probe is able to quench unwanted chemical reactions inside the probe for all engine power levels.

A Statistical Analysis in Solid Film Lubrication

1963 ◽  
Vol 85 (2) ◽  
pp. 286-290
Author(s):  
Martin R. Adams ◽  
Mary D. Lum
Keyword(s):  
Statistical Analysis ◽  
Weight Ratio ◽  
Test Results ◽  
Wear Life ◽  
Bearing Load ◽  
Solid Film ◽  
Block Temperature ◽  
Increasing Temperature ◽  
Film Lubrication ◽  
Made In

A factorial experiment was designed for evaluating the performance of a ceramic bonded solid film lubricant consisting of PbS/B2O3 in a 6:1 weight ratio. The effects of three factors, each at two levels were studied. These were bearing load, sliding speed, and rub block temperature. An analysis of variance of the test results was made. At 200 rpm, wear life increased with an increase in temperature between 700 and 1000 F for both load levels of 100 and 200 lb. At 600 rpm, however, wear life decreased with increasing temperature between 700 and 1000 F for both load levels. All results were obtained from runs made in air.

Minimizing Sampling Loss in Trace Gas Emission Measurements for Aircraft Engines by Using a Chemical Quick-Quench Probe

2011 ◽  
Vol 133 (7) ◽  
Author(s):  
Elena de la Rosa Blanco ◽  
Jay Peck ◽  
Richard C. Miake-Lye ◽  
Frank B. Hills ◽  
Ezra C. Wood ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Aircraft Engine ◽  
Trace Gas ◽  
Test Results ◽  
University Of Tennessee ◽  
Quench Probe ◽  
Gas Sampling ◽  
Helium Dilution ◽  
The University ◽  
Engine Power

This paper describes the development and testing of a gas sampling probe that quenches chemical reactions by using supersonic expansion and helium dilution. Gas sampling probes are required for accurate measurement of exhaust emissions species, which is critical to determine the performance of an aircraft engine. The probe was designed through rounds of computational modeling and laboratory testing and was subsequently manufactured and then tested at the University of Tennessee Space Institute behind a General Electric J85 turbojet engine at different power settings: idle, maximum military, and afterburning. The experimental test results demonstrated that the chemical quick-quench (CQQ) probe suppressed the oxidation of carbon monoxide (CO) inside the probe system and preserved more CO at afterburning conditions. In addition, the CQQ probe prevented hydrocarbons from being partially oxidized to form CO at idle powers and measured higher hydrocarbons and lower CO emission compared with a conventional probe at that low power condition. The CQQ probe also suppressed nitrogen dioxide (NO2) to nitric oxide (NO) conversion through all engine power settings. These data strongly support the conclusion that the CQQ probe is able to quench unwanted chemical reactions inside the probe for all engine power levels.

Thermal Tip Clearance Control for Centrifugal Compressor of an APU Engine

1993 ◽  
Author(s):  
G. Eisenlohr ◽  
H. Chladek
Keyword(s):  
Centrifugal Compressor ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Qualitative Description ◽  
Test Results ◽  
Aerodynamic Design ◽  
Main Attention ◽  
Design Calculations ◽  
Clearance Control ◽  
Engine Power

To master todays demand for efficiency and compactness of centrifugal compressor components for small gasturbine engines the main attention must not only be given to the aerodynamic design of the impeller and diffuser components, but also to the installation situation of the surrounding parts. A vital aspect is the tip clearance control between impeller and shroud casing over the total operating range. Using the radial compressor for a small gasturbine engine, developed at BMW Rolls-Royce, the importance of tip clearence control is demonstrated. The possibilities for influencing and optimizing passive tip clearance control by design features are described; transient expansion processes must be considered when using a thermal tip clearance control. The results of the design calculations are compared with the results on the teststand and the engine itself. An effort is made to find a qualitative influence of tip clearance to the engine power output at operating conditions. This qualitative description is substantiated by test results with different tip clearances at the compressor teststand.

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