scholarly journals FEM analysis of the opposed-piston aircraft engine block

2021 ◽  
Vol 2130 (1) ◽  
pp. 012034
Author(s):  
K Pietrykowski
Keyword(s):  
Tensile Force ◽  
Fem Analysis ◽  
Aircraft Engine ◽  
Engine Block ◽  
Main Bearing ◽  
Operating Process ◽  
Calculation Results ◽  
Engine Failure ◽  
Aero Engines ◽  
As Stress

Abstract An important aspect of aircraft engine design is weight minimization. However, excessive weight reduction may reduce mechanical strength of the engine. This is especially important for aero-engines due to consequences of engine failure in flight. The article presents the results of the FEM opposed-piston diesel engine block model tests. The tested engine is a PZL-100 two-stroke three-cylinder aircraft engine with two crankshafts and six pistons. Air is supplied via a mechanical compressor and a turbocharger. Stress in the engine block is induced by the operating process of the engine block. The pressure in the combustion chamber of the analyzed engine is 13 MPa. The pistons in one of the cylinders are then near their TDC, the deflection angle of the connecting rods is small so almost the entire piston force is transferred to the crankshafts and then to the main bearing supports. This results in the occurence of a tensile force for the engine block applied in the bolt holes of the shaft supports. The calculation results are presented as stress and displacement distributions on the surface and selected block sections. The maximum values on the outer surfaces of the block occurred in the area of the compressor attached to the block and reached 39 MPa. Maximum stresses were, however, observed inside the block on the air and exhaust flow separators between the cylinder liners. The stress value on the outlet side reached 44 MPa.

scholarly journals Stress analysis of the cylinder block of a small compression ignition engine

2019 ◽  
Vol 179 (4) ◽  
pp. 259-263
Author(s):  
Jerzy WAWRZYCZEK ◽  
Tomasz KNEFEL
Keyword(s):  
Stress Analysis ◽  
Cylinder Head ◽  
Engine Block ◽  
Cylinder Block ◽  
Small Displacement ◽  
Compression Ignition ◽  
Main Bearing ◽  
Compression Ignition Engine ◽  
Combustion Pressure

The work contains calculations to determine the deformation and stress in the block of a currently produced small displacement compression ignition engine. It is also an attempt to introduce some modifications to reduce the mass of the calculated component. In the first step, based on measurements, the model of the engine block was developed. The Autodesk Inventor 2016 software was used. Two additional components were also designed to provide the block closure: a simplified cylinder head and an integrated main bearing support. All elements were imported to the Siemens NX 12 program. The calculations were carried out for different cylinders and different values of the combustion pressure. An attempt was made to introduce some modifications to reduce the weight of the calculated element.

scholarly journals Decision Support System For Determining Power Loss And Refurbishability Of Failed Automotive Petrol Engine Block And Crankshaft

2021 ◽  
Author(s):  
BASIL OLUFEMI AKINNULI ◽  
OLADELE AWOPETU ◽  
OLUWASEUN OLUWAGBEMIGA OJO
Keyword(s):  
Decision Support ◽  
Power Loss ◽  
Computer Software ◽  
Engine Block ◽  
Measuring Instruments ◽  
Main Bearing ◽  
Test Engine ◽  
Cause Of Failure ◽  
Improved Performance ◽  
The Cost

Abstract The crankshaft and engine block of automobile wear or fail after certain years of usage. The cause of failure is a contributing factor to the power loss of the engine. Power loss reduces the performance of the vehicle. Due to the economic situation in Nigeria, the cost of buying new engines is usually high and some used engines have problems that are latent. Pre-test engine analysis was carried out and torque of each selected engine was measured with a dynamometer to know the speed of the worn engine. Disassembly of four (4) cylinder engines namely; Toyota, Nissan, Mitsubishi, and Mazda were carried out and the affected failed parts, namely; main bearing, crankpin journal, and bore cylinder diameter were determined and the level of their wear as well as power losses ascertained using measuring instruments. For easy computation and analysis, a computer software using C-sharp programming language was developed to determine the power loss and predicting machining level of refurbish-ability and tested for performance evaluation. The model and its developed software are decision support tools for any automotive industry where maintenance and management of engines for improved performance and efficiency of operation is the focus.

Research of Hard Fault Diagnosis Simulation Platform of Aero-Engine's Key Sensors Based on Neural Network

2013 ◽  
Vol 391 ◽  
pp. 150-154 ◽  
Author(s):  
Zhao Rong Sun ◽  
Yi Gang Sun ◽  
Chun Lin Sun Sun
Keyword(s):  
Neural Network ◽  
Fault Diagnosis ◽  
Simulation Platform ◽  
Bp Network ◽  
Fault Type ◽  
Diagnosis Model ◽  
Simulation Results ◽  
Engine Failure ◽  
Aero Engines ◽  
Hard Failure

The purpose of the research is to establish a fault diagnosis model of the aero-engines key sensors using the artificial neural networks to replace the engines mathematical model, so as to establish a hard fault diagnosis simulation platform to monitor the performances of the engine sensors on real-time, to judge the engine failure mode timely, and to locate the fault type of sensors accurately. By analyzing the correlations of the parameters that affect the conditions of the engine, a three-layer BP network model is established. The related QAR (Quick Access Recorder) data are used to simulate and analyze the models using the MATLAB. Combined with the characteristics of the hard failure of the critical engine sensors and the correlation of the parameters, the fault diagnosis simulation platform is established. Then, the parameters of the normal engine and the failure engine are used respectively to evaluate and validate the platform. The simulation results show that the platform can judge the critical sensors faults of the engine accurately, and can locate the type of sensors reliably.

GRIFFIN VENTURE GAS TURBINE FAILURE 1997

1999 ◽  
Vol 39 (1) ◽  
pp. 532
Author(s):  
K.R. Black
Keyword(s):  
Gas Turbine ◽  
Detection System ◽  
Short Circuit ◽  
Fire Detection ◽  
Turbine Engine ◽  
Fire Extinguishing ◽  
Power Turbine ◽  
Engine Failure ◽  
As Stress ◽  
Safety Systems

On 10 November 1997 the BHP Petroleum-operated Floating Production, Storage and Offloading (FPSO) crude oil facility the Griffin Venture suffered an unprecedented mechanical failure of a gas turbine engine. The power turbine casing was breached resulting in an explosion and fire within the engine room space. The incident was safely controlled without personnel injury in what was a world class emergency response effort.The engine failure was caused by an unusual form of crack propagation known as stress assisted grain boundary oxidation (SAGBO) of the engine's high pressure power turbine disc. The incident also identified a number of safety system improvements, many of which could be applicable to other facilities. These included smoke impairment of the accommodation (designated temporary safe refuge) because of leaking fire doors, failure to release the engine package fire extinguishing system and failure of the fire detection system due to short circuit intolerance nine minutes after the incident commenced.The facility was repaired in Singapore by Sembawang Shipyard where new engine cores were fitted and many of the safety systems were upgraded. Production resumed in March 1998 since when the Griffin Venture has produced above target oil volumes and record gas volumes.

Cycle Optimization Potential of Composite Cycle and Turbocompound Aero-Engines

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Felix Klein ◽  
Stephan Staudacher
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Exchange Process ◽  
Aircraft Engine ◽  
Time Frame ◽  
Fuel Burn ◽  
Component Efficiency ◽  
Low Efficiency ◽  
Aero Engines

Abstract Fair comparison of future aircraft engine concepts requires the assumption of similar technological risk and a transparent book keeping of losses. A 1000 km and a 7000 km flight mission of a single-aisle airplane similar to the Aribus A321neo LR have been used to compare composite cycle engines, turbocompound engines and advanced gas turbines as potential options for an entry-into-service time frame of 2050+. A 2035 technology gas turbine serves as reference. The cycle optimization has been carried out with a peak pressure ratio of 250 and a maximum cycle temperature of 2200 K at cruise as boundary conditions. With the associated heat loss and the low efficiency of the gas exchange process limiting piston component efficiency, the cycle optimization filtered out composite cycle concepts. Taking mission fuel burn (MFB) as the most relevant criterion, the highest MFB reduction of 13.7% compared to the 2035 reference gas turbine is demonstrated for an air-cooled turbocompound concept with additional combustion chamber. An intercooled, hectopressure gas turbine with pressure gain combustion achieves 20.6% reduction in MFB relative to the 2035 reference gas turbine.

FEM Analysis on Tensile Force of Geosynthetic Reinforcement Arranged in GRS-RW Considering Variable Loading Rate

2012 ◽  
Vol 188 ◽  
pp. 60-65
Author(s):  
Fu Lin Li ◽  
Fang Le Peng
Keyword(s):  
Finite Element ◽  
Loading Rate ◽  
Retaining Wall ◽  
Tensile Force ◽  
Fem Analysis ◽  
Reinforced Soil ◽  
Geosynthetic Reinforcement ◽  
Geosynthetic Reinforced Soil ◽  
Rate Dependent ◽  
Dependent Behavior

The combined effects of the rate-dependent behavior of both the backfill soil and the geosynthetic reinforcement have been investigated, which should be attributed to the viscous property of material. A nonlinear finite element method (FEM) analysis procedure based on the Dynamic Relaxation method was developed for the geosynthetic-reinforced soil retaining wall (GRS-RW). In the numerical analysis, both the viscous properties of the backfill and the reinforcement were considered through the unified nonlinear three-component elastic-viscoplastic model. The FEM procedure was validated against a physical model test on geosynthetic-reinforced soil retaining wall with granular backfill. Extensive finite-element analyses were carried out to investigate the tensile force distributions in geosynthetic reinforcement of geosynthetic-reinforced soil retaining wall under the change of loading rate. It is found from the analyses that the presented FEM can well simulate the rate-dependent behavior of geosynthetic-reinforced soil retaining wall and the tensile force of geosynthetic reinforcement arranged in retaining wall.

An Elastohydrodynamic Coupling of a Rotating Crankshaft and a Flexible Engine Block

2004 ◽  
Vol 126 (2) ◽  
pp. 233-241 ◽  
Author(s):  
Omidreza Ebrat ◽  
Zissimos P. Mourelatos ◽  
Kexin Hu ◽  
Nickolas Vlahopoulos ◽  
Kumar Vaidyanathan
Keyword(s):  
Finite Difference ◽  
Component Mode Synthesis ◽  
Engine Block ◽  
Main Bearing ◽  
Equilibrium Conditions ◽  
Structural Dynamic ◽  
Mapping Algorithm ◽  
Computational Capability ◽  
Body Dynamics ◽  
Flexible Body Dynamics

A comprehensive formulation is presented for the dynamics of a rotating flexible crankshaft coupled with the dynamics of an engine block through a finite difference elastohydrodynamic main bearing lubrication algorithm. The coupling is based on detailed equilibrium conditions at the bearings. The component mode synthesis is employed for modeling the crankshaft and block dynamic behavior. A specialized algorithm for coupling the rigid and flexible body dynamics of the crankshaft within the framework of the component mode synthesis has been developed. A finite difference lubrication algorithm is used for computing the oil film elastohydrodynamic characteristics. A computationally accurate and efficient mapping algorithm has been developed for transferring information between a high-density computational grid for the elastohydrodynamic bearing solver and a low-density structural grid utilized in computing the crankshaft and block structural dynamic response. The new computational capability is used to compute the vibratory response of an automotive V6 engine due to combustion and inertia loading.

Comparison of BLISS 2000 and CO in Turbine Blade MDO for Aircraft Engine

2013 ◽  
Author(s):  
Junjie Yang ◽  
Jingyang Chen ◽  
Jiachao Yan
Keyword(s):  
Weight Reduction ◽  
Thermal Structure ◽  
Turbine Blades ◽  
Fem Analysis ◽  
Aircraft Engine ◽  
Surrogate Models ◽  
System Level ◽  
Computational Accuracy ◽  
Numerical Example ◽  
The Impact

In this paper, the two methods of CO and BLISS 2000 are compared by using a classical numerical example firstly. The results show that the BLISS 2000 performs better in both computational accuracy and efficiency, because the scale of the optimization problem, such as the number of variables and constraints, in the BLISS 2000 is less than that in the CO. Moreover, the BLISS 2000 optimizes directly the system objectives while the CO focuses on decreasing the discrepancy between the coupled variables in different fields. The two methods are then applied to an aerodynamics-thermal-structure coupled design problem for the turbine blades of an aircraft engine. Based on the results of sensitivity analysis, the number of design variables is reduced from 34 to 12. To eliminate the impact of the surrogate models on the different MDO algorithms as much as possible, the same initial Kriging surrogate models are not refreshed during the MDO procedures. Without the high fidelity simulation such as CFD and FEM analysis in the MDO processes, the BLISS 2000 method shows the more powerful capability of the convergence than that of the CO method, as shown in the numerical example. The optimization steps of the system level for BLISS 2000 are approximate 1/5 of those for CO, and the iteration number of step in the sub-system level with BLISS 2000 is only about 1/8 of that with CO. Based on the weight sum of two objectives, the BLISS 2000 shows more robust than the CO because both weight reduction and aerodynamic efficiency are improved in the BLISS 2000 but only the blade weight reduction is gained in the CO. For other multi-objective optimization approaches, however, it still needs to be demonstrated through more studies.

Influence of Labyrinth Seal Leakage on the Turbine Support Cooling

2014 ◽  
Author(s):  
Alexandr S. Vinogradov ◽  
Renat R. Badykov
Keyword(s):  
Mutual Influence ◽  
Aircraft Engine ◽  
Labyrinth Seal ◽  
Engine Oil ◽  
Calculation Results ◽  
Different Temperatures ◽  
Supporting Element ◽  
Aviation Engines ◽  
Cooling Air ◽  
Quantity Of Heat

This paper presents a study of the seal of supporting element in aviation engines with consideration of the mutual influence of its leakage on parameters of internal air system and engine oil system. A method of seal leakage calculation was developed. It connects engine thermogasdynamics calculation, airflow hydraulics calculation and structural analysis of deformed parts. The main sources of heat transferred to the supporting element were determined; their numerical values and percentages for the compressor and turbine were also determined. This paper provides options of cooling the turbine support for realization of this method. A way of cooling the support determines the quantity of heat supplied to the support. Thus, this article analyzes the sources of heat. Comparison the amount of heat from different sources also is carried out. The amount of heat is defined the temperature of the cooling air. The article provides a comparison of calculation results for different temperatures of the cooling air. After selecting the geometry of the seal system, and determining of the total amount of heat, single seal from the system was researched. The main purpose of the paper is to explain the design of a single seal as part of whole seal system, which is used to cool the support of the aircraft engine.

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