Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

CFD Simulation Methodology for a Rotary Steam Expansion Piston Engine

2020-11-30
2020-32-2303
In industrial processes, combustion engines and co-generation plants, large amounts of waste heat are generated, which are often lost to the environment. The conversion of this thermal energy into mechanical work and ultimately into electrical power promises a significant improvement in energy utilization, the efficiency of the overall system and, consequently, cost-effectiveness. Therefore, the use of a Rankine Cycle is a well-established technical process. A recent research project investigates a novel expansion machine to be integrated into an RC-process to convert the heat energy into mechanical work. Primarily, the present work deals with the fluid dynamic simulation of this expander, which is based on the principle of a rotary piston engine. The aim is to develop, analyze and optimize the process and the corresponding components. Hence, a CFD model has to be built up, which should correspond as closely as possible to the requirements and geometries of the physical engine.
Standard

Lubricating Oil, Aircraft Piston Engine (Ashless Dispersant)

2020-10-28
CURRENT
J1899_202010
This SAE Standard establishes the requirements for lubricating oils containing ashless dispersant additives to be used in four-stroke cycle, reciprocating piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-22851. Users should consult their airframe or engine manufacturers manuals for the latest listing of acceptable lubricants.
Standard

Lubricating Oils, Aircraft Piston Engine (Non-Dispersant Mineral Oil)

2020-10-28
CURRENT
J1966_202010
This SAE Standard establishes the requirements for nondispersant, mineral lubricating oils to be used in four-stroke cycle piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-6082. Users should consult their airframe or engine manufacturers manuals for the latest listing of acceptable lubricants.
Technical Paper

An Investigation Study of the Thermomechanical Loading on the Piston of a Diesel Engine with Design Improvements

2020-10-22
2020-01-5098
The latest developments in the engine’s design aim to maximize the power output, downsize the engine, and minimize the fuel consumption. This paper investigates the thermomechanical loads on the piston of a turbocharged diesel engine. The main emphasis is the effect of increasing the boosting pressure on the piston loading until the possible maximum engine power is achieved. Also, it proposes the modification of the piston design in order to increase the durability for more power loading and decrease the total mass. The temperature distribution on the piston body, the corresponding thermomechanical deformations, the stress distribution, and the safety factor is excessively calculated. Finite element methods (ANSYS workbench) is used to analyze the thermomechanical loads applied to a three-dimensional model. The study is applied to the piston of a 300 hp diesel engine (base case) in order to increase the engine power by 17% (upgraded one).
Technical Paper

Optical Measurement of Spark Deflection Inside a Pre-chamber for Spark-Ignition Engines

2020-10-14
2020-01-5096
The start of combustion in a spark-ignited engine is highly dependent upon the conditions between the two spark plug electrodes at ignition. In addition to the air-to-fuel ratio in this gap, the gas flow is seen as most critical. In a combustion engine with a standard spark plug that protrudes into the combustion chamber, this gas flow is mainly dependent upon the tumble, swirl, or squish that is developed by the cylinder head and the piston movement. However, the air movement in the pre-chamber depends on the orientation of the orifices towards the main combustion chamber (MCC). This implies a less complex manipulation of local velocity in the electrode gap. This paper focuses on the effect of different pre-chamber designs on spark deflection by the inflowing gas. Therefore, a test rig was developed using the spark plug thread in the cylinder head of a motored engine.
Technical Paper

Real-World Application of Variable Pedal Feeling Using an Electric Brake Booster with Two Motors

2020-10-05
2020-01-1645
A new type of electric brake booster, which can control brake pedal feeling completely with software, has been developed to explore how a brake system can be used to differentiate and personalize vehicles. In the future, vehicles may share an increasing amount of hardware and rely more heavily on software to differentiate between models. Car sharing, vehicle subscriptions, and other new business models may create a new emphasis on the personalization of vehicles that may be achieved most cost effectively by using software. This new brake booster controls the brake pedal force and brake pressure independently based on the brake pedal stroke so that the pedal feeling is completely defined by software. The booster uses two electric motors and one master cylinder. One electric motor controls the pedal force and provides an assist force that amplifies the force that the driver applies to the brake pedal.
Technical Paper

Topology Optimisation of Brake Caliper

2020-10-05
2020-01-1620
The objective of the research is to develop a lightweight yet stiff, 2 piston fixed brake caliper which can be used in formula student race car. To make a race car, its components need to be lighter. To stop a car with minimum stopping distance, it needs to have a sophisticated braking system with well-designed components. The designing of the caliper is carried out on the Altair Inspire software. The topology optimisation algorithm is used to minimise the weight of the caliper without compromising the stiffness. The structural analysis is also carried out on the Altair Inspire. The caliper is also tested for fatigue failure using Ansys.
Journal Article

Neural Network-Based Prediction of Liquid-Phase Diffusion Coefficient to Model Fuel-Oil Dilution on Engine Cylinder Walls

2020-10-02
Abstract Nowadays the role played by passenger vehicles on the greenhouse effect is of great value. To slow down both global warming and fossil fuel wasting, the design of high-efficiency engines is compulsory. Downsized Turbocharged Gasoline Direct Injection (TGDI) engines comply with both high-efficiency and power demand requirements. Nevertheless, Direct Injection (DI) inside downsized chambers may result in the fuel wall impingement, depending on the operating conditions. The impact of fuel on the cylinder liner leads to the mixing of the fuel and the lubricant oil in the cylinder wall. When the piston moves, the piston top ring scraps the non-evaporated fuel-oil mixture. Then the scraped fuel-oil mixture may be scattered into the combustion chamber, becoming a source of diffusive flames in all conditions and abnormal combustions known as Low-Speed Pre-Ignitions (LSPI) at the highest loads.
Technical Paper

Reinforcement of Low-Frequency Sound by Using a Panel Speaker Attached to the Roof Panel of a Passenger Car

2020-09-30
2020-01-1570
The woofer in a car should be large to cover the low frequencies, so it is heavy and needs an ample space to be installed in a passenger car. The geometry of the woofer should conform to the limited available space and layout in general. In many cases, the passengers feel that the low-frequency contents are not satisfactory although the speaker specification covers the low frequencies. In this work, a thin panel is installed between the roof liner and the roof panel, and it is used as the woofer. The vibration field is controlled by many small actuators to create the speaker and baffle zones to avoid the sound distortion due to the modal interaction. The generation of speaker and baffle zones follows the inverse vibro-acoustic rendering technique. In the actual implementation, a thin acrylic plate of 0.53x0.2 m2 is used as the radiator panel, and the control actuator array is composed of 16 moving-coil actuators.
Standard

Measurement of the Total Ash Content of Aviation Piston Engine Oils by a Calculation Method

2020-09-29
CURRENT
J1787_202009
This SAE Recommended Practice describes an empirical method for determining the theoretical ash content of aviation piston engine lubricating oils by calculating the equivalent weight of metallic oxides formed at 775 °C based on the metallic elemental concentration. The calculation method of ash determination may be used as an alternate to ASTM D 482 for application to the standards for aviation piston engine lubricating oils.
Technical Paper

Correlation of Experimental Thermal Mapping and FEA Thermal Simulation for Cylinder Head for Diesel Engine Development

2020-09-25
2020-28-0353
For upgrading/new engine development, the piston and cylinder head are the most exposed members due to amplified mechanical and thermal loadings. Mechanical loading is basically due to the combustion gas pressure in the combustion chamber and its scale can be judged in terms of peak cylinder pressure. Thermal loading is due to temperature by heat flux acting on the piston surface, cylinder liner and the cylinder head. The importance of the various loads applied on the head and cylinder block in operation was assessed and a method of predicting their influence on the structural integrity of the components described by doing actual test on engine test bench. Therefore, it’s very important to have thermal survey of the engine. The engine thermal survey test was primarily developed to measure the temperature in the head of the engine to determine if the temperatures that are measured are within the design guidelines for appropriate engine operation.
Technical Paper

Modeling and Simulation of Automotive AC Components (Condenser & Piston) with Experimental Validation

2020-09-25
2020-28-0357
Automotive Air Conditioning is the process of removing the heat and moisture from the interior of an occupied space to improve comfort of occupants. A condenser is a device or unit used to condense refrigerant from its gaseous to its liquid state, by cooling it. In so doing, the latent heat is given up by the substance and transferred to the surrounding environment. It is made of Aluminum Alloy Material and subjected to very high internal stresses due to refrigerant pressure, thermal / inertia and dynamic load. In order to evaluate the structural integrity of the condenser assembly under these loading conditions, operating frequency should be far away from the resonance frequency and component design should be robust to sustain external excitation load coming from the engine & road. The above design evaluation criteria is also applicable for piston of AC’s reciprocating compressor.
Technical Paper

Assessment of the Metallurgical and Mechanical Properties of Stir cum Squeeze Cast A356 with 5wt. % SiC and x wt. % Flyash Hybrid Composites

2020-09-25
2020-28-0397
The forged connecting rod and pin experience a large amount of stresses due to cyclic load for a long period of time induced by the reciprocating movement of the piston. The proposed work focused to produce lightweight composites with high strength using waste flyash and simple manufacturing process. In this context, the proposed experimental work was formulated to develop aluminium alloy hybrid metal matrix composite of A356 alloy with silicon carbide and flyash processed through stir cum squeeze casting process under optimal parametric condition. The samples were subjected to varying flyash content of 0, 5, 10wt.% and SiC of 5wt.% kept constant. Responses like metallography, hardness, impact strength, flexural strength, fatigue strength were observed for the manufactured hybrid composites. There was a significant improvement in the properties with a higher weight percentage addition of 10wt.% flyash and 5wt.% SiC with A356 hybrid composites.
Technical Paper

Design and Couple Field Analysis of Uncoated and Coated Aluminium Metal Matrix Hybrid Composite Piston

2020-09-25
2020-28-0391
Piston is the most imperative part of an automotive engine in which it exchanges drive due to expanding gas in the cylinder to the crankshaft through the piston rod. During the combustion of fuel charge inside the ignition chamber, high pressure and temperature are developed and the piston is imperiled to high mechanical and thermal stresses. The main objective of the proposed work is to analyse the stress distributions and thermal behaviour of uncoated A356 with 5wt% SiC and 10wt% Fly Ash HMMC piston crown and Plasma sprayed Yttrium Stabilized Zirconia (Y-PSZ) coated A356 with 5wt% SiC and 10wt% Fly Ash HMMC piston crown. A356 with 5wt% SiC and 10wt% Fly Ash HMMC were fabricated via squeeze casting to improve the performance of a petrol engine. A structural model of an HMMC piston crown was made using CREO software and structural and thermal analysis was done using ANSYS. Further coupled field analysis is done to find the stress and temperature distribution on the piston.
Technical Paper

Concept to Start-of-Production Powertrain Bearing Analysis

2020-09-25
2020-28-0326
Future’s internal combustion engines request maximum efficiency with absolute safety and durability. The current market trend imposes maximum strain on bearings. The major bearings are cam shafts, piston pin and piston boss bearings, crankshaft main bearings, conrod big end and crank pin bearings and selection of correct layout for these bearings becomes critical. Simulations can assist to achieve a good and production ready design with shorter development cycles. In this paper an easy-to-use bearing modelling approach is proposed, with a focus on Thermo-Elasto-Hydrodynamic (TEHD) solution. This approach recognizes many different applications and systems within the powertrain and need for borderline designs directly from the concept phase of engine development. The hydrodynamics module is completely integrated into multi body simulation (MBS) as force elements. This allows interaction between the structural dynamics and bearing hydrodynamics to improve the quality of results.
Technical Paper

Numerical Analysis of the System Piston-Ring-Cylinder of an Automotive IC Engine

2020-09-15
2020-01-2160
A set of piston rings is used to form a dynamic gas seal between the piston and cylinder wall. Many physical phenomena are associated with the operation of the system piston-ring-cylinder (PRC), such as: inter-ring gas dynamics for the labyrinth seal, hydrodynamic lubrication and mixed friction in gaps between the rings and cylinder liner, oil flow and distribution of lubricant along the liner, twist motion of rings, liner temperature influence on the oil viscosity. The first part of the paper presents a comprehensive model of the PRC system developed by the author. Among own models it includes several models taken from literature, like: a model of viscous oil flow between rough gap surfaces formulated by Patir & Cheng and an elastic contact model of Greenwood & Tripp. The main parts of developed mathematical model and software have been experimentally verified during a research period of the author at the marine engine designing centre ”Wärtsilä” in Switzerland.
Technical Paper

New Methods and Systems for Monitoring the Functional Stability Parameters of Wheel Machines Power Units

2020-09-15
2020-01-2014
The methods and principles of monitoring and diagnosing the parameters of power units are generalized. They allow increasing the wheeled vehicles operational reliability. Systems for monitoring the functional stability parameters of the most sensitive to operating conditions systems and assemblies of machines have been developed on the example of a cylinder-piston engine group and steering. An improved method for diagnosing the steering of an articulated wheeled vehicle, which significantly affects the safety of its use, is proposed based on the use of angular accelerations of sections in the road plane as a diagnostic parameter. The dependence for determining the angular accelerations for the case of the random installation of two sensors of the mobile registration and measuring complex on the machine, which allows increasing the accuracy of measurements, is obtained. Experimental studies to diagnose the steering of wheeled vehicles with various operating times have been carried out.
Technical Paper

Stereoscopic Micro-PIV Measurement of Near-Wall Velocity Distribution in Strong Tumble Flow under Motored SI Engine Condition

2020-09-15
2020-01-2019
In a state-of-the-art lean-burn spark ignition engine, a strong in-cylinder flow field with enhanced turbulence intensity is formed, and understanding the wall heat transfer mechanism of such a complex flow is required. The flow velocity and temperature profiles inside the wall boundary layer are strongly related to the heat transfer mechanism. In this study, two-dimensional three-component (2D3C) velocity distribution near the piston top surface was measured during the compression stroke in a strong tumble flow using a rapid compression and expansion machine (RCEM) and a stereoscopic micro-PIV system. The bore, stroke, compression ratio, and compression time were 75 mm, 128 mm, 15, and 30 ms (equivalent to 1000 rpm), respectively.
Technical Paper

The Use of a Low Frequency Vibration Signal in Detecting the Misfire of a Cylinder of an Aircraft Piston Engine

2020-09-15
2020-01-2023
The following article describes the low frequency vibration analysis of aircraft piston engine Rotax 912 ULS. The results are based on the vibration signal made by the engine in the frequency range up to 400 Hz measured on the engine block in three axes. The aim of the research was to determine the method of detecting the misfire of individual cylinders based on the power spectrum of the selected frequencies analysis. Frequencies resulting from the periodicity of engine operation related to the frequency of the work cycle, rotational speed and ignition frequency were considered for the analysis. The tests were carried out in one point of operation. The highest levels of changes were recorded in the Y axis - the axis of piston movement. It was shown that the vibration level changes after switching off one of the cylinders.
X