Fatigue design of a twin internal combustion engine for a light helicopter by a CAE-based approach

2017 ◽  
Vol 8 (6) ◽  
pp. 632-647 ◽  
Author(s):  
Andrea Gilioli ◽  
Dario Braconi ◽  
Mario Guagliano
Keyword(s):  
Internal Combustion Engine ◽  
Structural Integrity ◽  
Combustion Engine ◽  
High Reliability ◽  
Internal Combustion ◽  
Connecting Rod ◽  
Content Type ◽  
Safety Standards ◽  
Operative Costs ◽  
Fail Safe

Purpose The purpose of this paper is to apply a computer-aided engineering approach in order to improve the performance and the reliability of an innovative internal combustion engine. The engine is called twin engine packs system and it consists into the presence of two independent piston engines working in the same crankcase, thus allowing the helicopter to meet the safety standards of the fail-safe design approach, as happens with the twin-turbine helicopters, but with reduced operative costs. The goal is to propose to the designers modifications aimed to improve the performance of the components. Design/methodology/approach The crankshaft, connecting rod and the piston of the engine have been investigated by means of numerical FE models. Numerical fatigue assessments have been performed along with vibrational modes and buckling analysis in order to verify the structural integrity of the system. Findings On the basis of the numerical results, some modifications have been proposed to the designers and the originally proposed geometry has been modified. Eventually, the mass of the engine has been reduced keeping a high reliability level. Practical implications The prototype of the engine has been built following the modifications proposed in this paper. This paper represents a comprehensive application of a CAE methodology to a real industrial application. Originality/value This paper shows a complete CAE procedure applied to a real working engine whose performances and reliability have been improved by following the findings of this paper.

Modeling the inertial torque imbalance and foundation forces within an inline internal combustion engine : quantifying the equivalent mass approximation

2018 ◽  
Author(s):  
◽  
Muslim Muhsin Ali
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Reaction Force ◽  
Internal Combustion ◽  
Significant Loss ◽  
Cylinder Wall ◽  
Connecting Rod ◽  
Piston Engine ◽  
Mass Approximation ◽  
Inertial Torque

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The main object of this dissertation is to study the dynamic analysis of an inline internal combustion engine. This dissertation presents the kinematics and kinetic analyses of an inline internal combustion engine crank mechanism, the dynamic torque imbalance and foundation forces for a single-piston and multi-piston engines are studied as well. The objectives of this dissertation are to explore the inertial-torque characteristics and foundation forces of an inline, internal combustion engine with connecting-rod joints that are evenly spaced about the centerline of the crankshaft, and to evaluate the goodness of a mass approximation that is customarily used in machine design textbooks. In this dissertation the number of pistons within the internal combustion engine is varied from 1 to 8. In order to generalize the results, the reaction force between the ground and the crank in the x-direction and y-direction equations are nondimensionalized and shown to depend upon only six nondimensional groups, all related to the mass and geometry properties of the connecting rod and crank while the reaction force between the connecting rod and the piston in the x-direction y-direction, reaction force between the crank and the connecting rod in the x-direction y-direction, reaction force between the piston and the cylinder wall, and the inertial-torque equations are nondimensionalized all related to the mass and geometry properties of the connecting rod. As shown in this dissertation, the largest torque imbalance is exhibited by a 2-piston engine. The next largest torque imbalance is exhibited by a 3-piston engine, followed by a single-piston engine (this is not monotonic). The largest foundation forces are exhibited by a single-piston engine. The next largest foundation forces are exhibited by a 2-piston engine, followed by a 3e-piston engine, and that a dramatic reduction in the foundation forces and torque imbalance may be obtained by using 4 or more pistons in the design, when using as many as 8 pistons the foundation forces and torque imbalance essentially vanishes. It should be observed that the mass approximation captures 100 percent of the variability of the actual torque imbalance for engines that are designed with an odd number of pistons equal to or greater than three. The mass approximation captures 100 percent of the variability of the actual reaction force between the piston and cylinder wall for engines that are designed with single-piston and multi-pistons. The mass approximation captures 100 percent of the variability of the actual reaction force against piston pin for engines that are designed with single-piston. It is also shown in this dissertation that the customary mass approximations for the connecting rod may be used to simplify the analysis for all engine designs without a significant loss of modeling accuracy.

Influence of positive texturing on friction and wear properties of piston ring-cylinder liner tribo pair under lubricated conditions

2019 ◽  
Vol 71 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Venkateswara Babu P. ◽  
Ismail Syed ◽  
Satish Ben Beera
Keyword(s):  
Wear Resistance ◽  
Internal Combustion Engine ◽  
Friction And Wear ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Tribological Performance ◽  
Friction Reduction ◽  
Content Type

Purpose In an internal combustion engine, piston ring-cylinder liner tribo pair is one among the most critical rubbing pairs. Most of the energy produced by an internal combustion engine is dissipated as frictional losses of which major portion is contributed by the piston ring-cylinder liner tribo pair. Hence, proper design of tribological parameters of piston ring-cylinder liner pair is essential and can effectively reduce the friction and wear, thereby improving the tribological performance of the engine. This paper aims to use surface texturing, an effective and feasible method, to improve the tribological performance of piston ring-cylinder liner tribo pair. Design/methodology/approach In this paper, influence of positive texturing (protruding) on friction reduction and wear resistance of piston ring surfaces was studied. The square-shaped positive textures were fabricated on piston ring surface by chemical etching method, and the experiments were conducted with textured piston ring surfaces against un-textured cylinder liner surface on pin-on-disc apparatus by continuous supply of lubricant at the inlet of contact zone. The parameters varied in this study are area density and normal load at a constant sliding speed. A comparison was made between the tribological properties of textured and un-textured piston ring surfaces. Findings From the experimental results, the tribological performance of the textured piston ring-cylinder liner tribo pair was significantly improved over a un-textured tribo pair. A maximum friction reduction of 67.6 per cent and wear resistance of 81.6 per cent were observed with textured ring surfaces as compared to un-textured ring surfaces. Originality/value This experimental study is helpful for better understanding of the potency of positive texturing on friction reduction and wear resistance of piston ring-cylinder liner tribo pair under lubricated sliding conditions.

The Research and Application of the Internal Combustion Engine Power Plant--Rotary UPS Monitoring Systems

2011 ◽  
Vol 328-330 ◽  
pp. 2207-2210
Author(s):  
Xiao Jing Sun ◽  
Xing Gui Wang ◽  
Chun Ning Wang
Keyword(s):  
Power Plant ◽  
Internal Combustion Engine ◽  
Power Supply ◽  
Combustion Engine ◽  
High Reliability ◽  
Internal Combustion ◽  
System Structure ◽  
Monitoring Systems ◽  
Continuous Power ◽  
Engine Power

The Internal Combustion Engine Power Plant and Flywheel Battery were the two primarily compositive units of the Internal Combustion Engine Power Plant --Rotary UPS, among them the Internal Combustion Engine Power Plant ensured the continuous power supply to the load after the breaking of the mains supply, the Flywheel Battery ensured the uninterruptible continuous power supply to the load when mains supply switched to the Internal Combustion Engine Power Plant, so the paper started with the two units, Introduced the control system structure and principle, and focused on discussing the method of achieving the Internal Combustion Engine Power Plant --Rotary UPS telecommunication by Ethernet. The method had been applied in correlative production. The practice showed that it was convenient for usage and high reliability.

Probabilistic Tolerance Allocation for the Dynamics of an Internal Combustion Engine With a Flexible Connecting Rod

1997 ◽  
Author(s):  
F. Zhang ◽  
B. J. Gilmore ◽  
A. Sinha
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Equations Of Motion ◽  
Optimization Procedure ◽  
Internal Combustion ◽  
Tolerance Allocation ◽  
Radial Clearance ◽  
Connecting Rod ◽  
Link Length ◽  
Design Variables

Abstract Tolerance allocation standards do not exist for mechanical systems with flexibility and whose response are time varying, subjected to discontinuous forcing functions. Previous approaches based on optimization and numerical integration of the dynamic equations of motion encounter difficulty with determining sensitivities around the force discontinuity. The Alternating Frequency/Time approach is applied here to capture the effect of the discontinuity. The effective link length model is used to model the system and to account for the uncertainties in the link length, radial clearance and pin location. Since the effective link length model is applied, the equations of motion for the nominal system can be applied for the entire analysis. Optimization procedure is applied to the problem where the objective is to minimize the manufacturing costs and satisfy the constraints imposed on mechanical errors and design variables. Examples of tolerance allocation are presented for a single cylinder internal combustion engine with a flexible connecting rod.

Effect of axial piston pin motion on tribo-dynamics of piston skirt-cylinder liner system

2018 ◽  
Vol 70 (1) ◽  
pp. 140-154
Author(s):  
Fanming Meng ◽  
Minggang Du ◽  
Xianfu Wang ◽  
Yuanpei Chen ◽  
Qing Zhang
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Axial Motion ◽  
Content Type ◽  
Piston Skirt ◽  
Operation Conditions ◽  
Liner System ◽  
Axial Piston

Purpose The purpose of this study is to investigate the effects of the axial piston pin motion on the tribological performances of the piston skirt and cylinder liner vibration for an internal combustion engine (ICE) under different operation conditions. Design/methodology/approach The dynamic equation for the piston incorporating into axial piston pin motion is derived first. Then, the proposed equation and associated lubrication equations are solved using the Broyden algorithm and difference method, respectively. Moreover, the axial motion of the piston pin and its slap on the cylinder liner are studied under different operation conditions. Findings The axial piston pin motion leads to an overall increase in the friction power consumption. Increments in the ICE speed and lubricant viscosity can augment the axial pin motion and cylinder liner vibration, especially in the power stroke. The said increments cause the instability of the piston motion in the cylinder. The axial motion of piston pin can be restrained through the eccentricity of the piston pin close to the thrust side of the cylinder liner. Originality/value This study conducts detailed discussions of the effect of axial piston pin motion on tribological and dynamic performances for piston skirt-cylinder liner system of an internal combustion engine and gives a helpful reference to analyses and designs of internal combustion engines.

Thermo-Elastohydrodynamic Analysis of Connecting Rod Bearing in Internal Combustion Engine

2001 ◽  
Vol 123 (3) ◽  
pp. 444-454 ◽  
Author(s):  
Byung-Jik Kim ◽  
Kyung-Woong Kim
Keyword(s):  
Internal Combustion Engine ◽  
Elastic Deformation ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Variable Viscosity ◽  
Elastohydrodynamic Lubrication ◽  
Internal Combustion ◽  
Thermal Distortion ◽  
Connecting Rod ◽  
Lubrication Film

A comprehensive method of thermo-elastohydrodynamic lubrication analysis for connecting rod bearings is proposed, which includes thermal distortion as well as elastic deformation of the bearing surface. Lubrication film temperature is treated as a time-dependent, two-dimensional variable which is averaged over the film thickness, while the bearing temperature is assumed to be time-independent and three-dimensional. It is assumed that a portion of the heat generated by viscous dissipation in the lubrication film is absorbed by the film itself, and the remainder flows into the bearing structure. Mass-conserving cavitation algorithm is applied, and the effect of variable viscosity is included in the Reynolds equation. Simulation results of the connecting rod bearing of an internal combustion engine are presented. It is shown that the predicted level of the thermal distortion is as large as that of the elastic deformation and the bearing clearance, and that the thermal distortion has remarkable effects on the bearing performance. Therefore, the thermo-elastohydrodynamic lubrication analysis is strongly recommended to predict the performance of connecting rod bearings in internal combustion engines.

Keeping twin turbocharged engine power at flight altitudes

2018 ◽  
Vol 90 (6) ◽  
pp. 906-913 ◽  
Author(s):  
Mohammad Reza Khodaparast ◽  
Mohsen Agha Seyed Mirza Bozorg ◽  
Saeid Kheradmand
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Pressure Ratio ◽  
Internal Combustion ◽  
Content Type ◽  
One Dimensional ◽  
Effective Performance ◽  
Different Altitudes ◽  
Engine Power

Purpose The purpose of this paper is the selection and arrangement of turbochargers set for internal combustion engine which could keep engine power in an altitude of up to 12.2 km above sea level. Design/methodology/approach In the current research, the target engine, a one-dimensional four-stroke 1,600 cc piston engine has been simulated and the manufacturer’ results have been validated. Depending on engine size, three proper types of Garret turbochargers GT30, GT25 and GT20 were selected for this engine. Then, the engine and a combination of two turbochargers have been modeled one-dimensionally. A control system was used for regulation of different pressure ratios between the two turbochargers. Findings The parametric analysis shows that using the combination of GT20, GT30 turbochargers with a properly controlled pressure ratio leads to a constant output power with little changes at different altitudes which enable achieving an altitude of 12.2 km for the target engine. Practical implications Adaptation of the internal combustion engine with a twin turbocharger using one-dimensional modeling. Originality/value The one-dimensional analysis provided an overall picture of the effective performance of turbochargers functioning in different altitudes and loads. It presents a new method for adopting of turbochargers set with internal combustion engines for propulsion medium-altitude aircraft.

scholarly journals Research on optical flat models of stresses in the crankpin of internal combustion engine

2018 ◽  
Vol 224 ◽  
pp. 02015
Author(s):  
Olga Zhed ◽  
Vladimir Kopylov ◽  
Adolf Koshelenko
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Quantitative Composition ◽  
Connecting Rod ◽  
Qualitative And Quantitative ◽  
Working Cycle

The intensity of the contour strains of the oil channel is determined by the method of photomechanics in the consequence of the loads of the crankpin in the working cycle of the internal combustion engine. The studies have made it possible to establish the qualitative and quantitative composition of the stresses on the hole contour of the oil channel against deformation of the bending and torsion of its connecting rod.

An Advanced Reciprocating Internal Combustion Engine Without Crankshaft and Connecting Rod Mechanisms

2006 ◽  
Author(s):  
Bogdan T. Fijalkowski
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Output Shaft ◽  
Reciprocating Motion ◽  
Connecting Rod ◽  
Mechanical Motion ◽  
Higher Power ◽  
Magneto Rheological ◽  
Power Densities

An advanced reciprocating internal combustion engine without a crankshaft and connecting rod mechanisms that the author would like to present is based on another law of physics. The invention titled ‘Nano-Magneto-Rheological Mechatronic Commutator Internal Combustion Engine’, that is concisely termed the Fijalkowski engine by someone, is based on a whole new propulsion engineering solution that has no analogies in the world. Thus, this paper focuses on an advanced reciprocating internal combustion engine termed the Fijalkowski engine, which may utilize a nano-magneto-rheological mechatronic commutator that may replace the crankshaft and connecting rod (conrod) mechanisms. This mechatronic commutator may let nano-magneto-rheological rotary ratchets oscillate in a controlled wobble while keeping the output shaft spinning smoothly; and although opposed pistons and opposed cylinders similar to those in automotive ‘boxer’ engines may power the Fijalkowski engine, it may also utilize opposed cylinders containing four pairs of two end-to-end opposed pistons for higher power densities. The nano-magneto-rheological mechatronic commutator may be utilized to convert between one form of mechanical motion that is linear, reciprocating motion of pistons and another — that is rotary motion of the output shaft.

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