scholarly journals An analysis of aspects of a rotary engine with an epitrochoid as rotor

1985 ◽  
Vol 4 (3) ◽  
pp. 85-90
Author(s):  
H. J. Le Roux
Keyword(s):  
Internal Combustion Engine ◽  
Surface Area ◽  
Combustion Engine ◽  
Volume Ratio ◽  
Internal Combustion ◽  
Movement Kinematics ◽  
Rotary Engine ◽  
Different Types ◽  
Sealing Elements

In order to evaluate and compare the different types of internal combustion engine various models are needed. This paper reports on an analysis of various aspects of a rotary internal-combustion engine using an epitrochoid as rotor. Aspects such as rotor movement, kinematics of sealing elements as well as displacement volume are considered. In the discussion certain other aspects such as surface-area to volume ratio and compression ratios are included.

Micro, Internal-Combustion Engine Fabrication With 900 µm Deep Features Via DRIE

2003 ◽  
Author(s):  
Aaron J. Knobloch ◽  
Matt Wasilik ◽  
Carlos Fernandez-Pello ◽  
Albert P. Pisano
Keyword(s):  
Internal Combustion Engine ◽  
Cross Sections ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Spur Gear ◽  
Planar Geometry ◽  
Etch Depth ◽  
Sidewall Roughness ◽  
Rotary Engine ◽  
Wankel Engine

New results are presented for the development of a micro, internal-combustion engine fabricated in a process that achieves 900 μm deep features via deep reactive ion etching (DRIE). A single-sided 900 μm deep etch process with high mask selectivity is used to generate straight sidewall structures with low sidewall roughness. This research is part of an effort to create a portable, MEMS-based Rotary Engine Power System (MEMS REPS) capable of producing power on the order of milliwatts with an energy density better than that of a conventional battery. The MEMS REPS is based on the planar geometry and self-valving operation of a Wankel engine with an integrated electrical generator. A generator and stator colocated within the engine rotor and housing eliminates the need for any external shafts, couplings, or seals. The rotary internal combustion engine is composed of 5 major comonents: a 900 μm deep rotor with soft magnetic poles and 25 μm wide in-plane cantilever beams which act as apex seals, a 900 μm deep epitrochoid housing with intake and exhaust ports, rear plate with spur gear, a top plate, and a shaft. This configuration was chosen in order to eliminate the effect of beaching during timed DRIE etches and to minimize engine leakage while maximizing spur gear teeth resolution, and simplifying engine fabrication. However, this configuration requires some assembly and optimization of DRIE parameters for each component. The rotor and epitrochoid housing are co-fabricated on the same wafer to minimize deviation in thickness and match etch behavior between mating components. This approach forces the generation of a mask with narrow, deep trenches (to define the cantilever apex seals on the rotors) in proximity to large “tub” etches (to define the engine housing). High etch cycle pressures improved etch selectivity to over 350:1 with respect to oxide and 150:1 to photoresist which is necessary for 900 μm deep features. High pressure also improved sidewall profile of the etched structures. Engine cross-sections show an 8 μm wall deviation on either side of a 250 μm trench through an etch depth of 867 μm. In addition to good sidewall straightness, these etch parameters give a low sidewall roughness through the generation of small size scallops on the sidewalls. However, the side effects of these etch parameters include silicon “grass” at the bottom of the trench, poor etch uniformity across the wafer, and increased effect of aspect ratio dependent etching. Some strategies to overcome these effects are discussed.

scholarly journals Experimental state of tensile testing of aircraft reciprocating internal combustion engine

2021 ◽  
Author(s):  
Matúš Mrva ◽  
◽  
Pavol Pecho
Keyword(s):  
Internal Combustion Engine ◽  
Tensile Testing ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Tensile Tests ◽  
Operating Characteristics ◽  
Piston Engine ◽  
Measuring Device ◽  
Different Types ◽  
The Creation

The main goal of the Paper "Experimental state of tensile tests of aircraft piston internal combustion engine" is to create an experimental and fully functional measuring stand for monitoring the parameters of a model internal combustion piston engine, using different types of propellers. The partial goals are the creation of a teaching aid, the construction of a unique facility and the creation of opportunities for research and development in this area by other students. Using a measuring device, it was possible to record the various operating characteristics of the internal combustion engine. Based on this, the usability of individual propellers for the measured internal combustion engine can be determined.

Apex Seal Design for the MEMS Rotary Engine Power System

2003 ◽  
Author(s):  
Fabian C. Martinez ◽  
Aaron J. Knobloch ◽  
Albert P. Pisano
Keyword(s):  
Power System ◽  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Combustion Process ◽  
Internal Combustion ◽  
Analytical Models ◽  
Planar Geometry ◽  
Rotary Engine ◽  
Seal Design ◽  
Engine Power

Design, modeling, and analysis of a novel in-plane cantilever apex seal for maintaining high compression ratios in a MEMS-based rotary internal combustion engine are presented. This work is part of an effort to create a portable, MEMS-based Rotary Engine Power System (MEMS REPS) capable of producing power on the order of tens of milliwatts and with an energy density better than that of a conventional battery. A Wankel-type rotary engine is advantageous for a MEMS-based internal combustion engine due to its planar geometry, self-valving operation, and few moving parts. Large scale rotary engines typically incorporate a complex apex and face sealing system composed of many parts and involved assembly. A MEMS-based apex seal system can be incorporated as part of the rotor in order to eliminate manual assembly. The seal system must also have a minimal footprint and closely follow the epitrochoid profile in order to effectively integrate with the other engine systems. Based on these objectives, an integrated in-plane cantilever apex seal system can be integrated into the rotor with a small footprint. The first step in the development of the MEMS REPS is an air-powered expander which can be used to demonstrate electrical generator operation, engine rotation, and apex seal operation. The apex seals discussed here are optimized for use in an air-powered expander. A performance analysis of this flexure apex seal design is performed which examines 4 major performance constraints: resonant frequency, strain, pressure, and power dissipation. In addition, the seal design also accounts for fabrication tolerances of thick deep reactive ion etching (DRIE). During operation, dynamic effects due to combustion process and mechanical translation may drive the flexures into resonance, leading to galloping of the cantilever tips. Galloping will result in large leakage paths, thereby, reducing the compression ratio. A 0.25% strain limit is imposed to minimize the effect of fatigue on seal performance. Pre-compressed apex seals are used to counteract forces generated on the apex seal due to a pressure differential. The apex seal is also designed to minimize the power dissipated due to frictional losses. To model the cantilever apex seal, two different loading conditions are examined. One condition is distinguished by point loading at the tip, when contact is made between the seal and housing wall. Another condition is characterized by a distributed loading, due to the changing pressure by both the compression and the combustion events. Analytical models in addition to a finite element analysis were performed.

Kinematics of the Cycloidal Internal Combustion Engine Mechanism

1993 ◽  
Vol 115 (4) ◽  
pp. 953-959 ◽  
Author(s):  
A. J. Shih
Keyword(s):  
Mathematical Modeling ◽  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Fuel Injector ◽  
Combustion Chambers ◽  
Planetary Gears ◽  
Rotary Engine ◽  
Complete Revolution

The application of the characteristics of cycloidal curves for the four-stroke rotary internal combustion engine mechanism is introduced. The major components of the cycloidal engine mechanism include a flywheel, a stationary sun gear, planetary gears, rotary bars, and rotary pistons. The rotary pistons are fixed to bars driven by pins of the planetary gears, and these pins follow a common trajectory of epicyloidal or hypocycloidal curve. Several combustion chambers are created by the rotary pistons. As the flywheel makes a complete revolution, the relative motion between rotary pistons and the specially positioned intake ports, exhaust ports, and fuel injector generate four-stoke cycles within each of the combustion chambers. The constraint and classification of the application of different cycloidal curves for the rotary engine mechanism are then presented. Further, the mathematical modeling is developed. The position, velocity, and acceleration analyses of the rotary pistons of the cycloidal engine mechanisms are presented.

scholarly journals Experimental state of thrust testing of aircraft reciprocating internal combustion engine

AEROjournal ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 15-18
Author(s):  
Matúš Mrva ◽  
◽  
Pavol Pecho ◽  
Michal Hrúz ◽  
Iveta Škvareková ◽  
...  
Keyword(s):  
Internal Combustion Engine ◽  
State Of The Art ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Measuring Device ◽  
Fuel Flow ◽  
Different Types ◽  
The University ◽  
Complex Measuring

The project “Experimental State of Thrust Testing of Aircraft Reciprocating Internal Combustion Engine” is aimed at creating a complex measuring device in order to obtain selected characteristics and parameters of the engine using different types of propellers. In addition to the basic measured parameters such as. thrust, temperature, speed and fuel flow will be a state of the art to test the latest prototype propellers designed for aircraft models. After its construction, the experimental state will be used as a study aid for testing various types of conventional as well as currently developed propellers, engine characteristics and teaching of the whole equipment in the process of teaching, training of aircraft mechanics and for presentation purposes of the University of Žilina.

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

2020 ◽  
pp. 62-80
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко
Keyword(s):  
Control System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Detection Range ◽  
Acoustic Signature ◽  
Static Conditions

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

CONVERTING THE VEHICLE BY REPLACING THE INTERNAL COMBUSTION ENGINE

2019 ◽  
pp. 29-35
Author(s):  
Oleksandr Gryshchuk ◽  
Volodymyr Hladchenko ◽  
Uriy Overchenko
Keyword(s):  
Internal Combustion Engine ◽  
Electric Vehicle ◽  
Electric Motor ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Environmental Safety ◽  
Environmental Conservation ◽  
Sales Forecasts ◽  
Financial Investments ◽  
Near Future

This article looks at some comparative statistics on the development and use of electric vehicles (hereinafter referred to as EM) as an example of sales and future sales forecasts for EM in countries that focus on environmental conservation. Examples of financial investments already underway and to be made in the near future by the largest automakers in the development and distribution of EM in the world are given. Steps are taken to improve the environmental situation in countries (for example, the prohibition of entry into the city center), the scientific and applied problem of improving the energy efficiency and environmental safety of the operation of wheeled vehicles (hereinafter referred to as the CTE). The basic and more widespread schemes of conversion of the internal combustion engine car (hereinafter -ICE) to the electric motor car (by replacing the gasoline or diesel electric motor), as well as the main requirements that must be observed for the safe use and operation of the electric vehicle. The problem is solved by justifying the feasibility of re-equipment of the KTZ by replacing the internal combustion engine with an electric motor. On the basis of the statistics collected by the State Automobile Transit Research Institute on the number of issued conclusions of scientific and technical expertise regarding the approval of the possibility of conversion of a car with an internal combustion engine (gasoline or diesel) to a car with an electric motor (electric vehicle), the conclusions on the feasibility of such conclusion were made. Keywords: electricvehicles, ecological safety, electricmotor, statistics provided, car, vehicle by replacing.

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