Design of a small Wankel engine

[[abstract]]This work presents a novel design of an ultra-small Wankel engine. With a device size of mm range and required power of mW, the rotation speed is theoretically calculated up to thousands of rpm. The PDMS MEMS process has been employed to make the Wankel engine planar and tiny. How to selecting the proper materials heterogeneously in the design stage of this engine is demonstrated herein.[[incitationindex]]EI[[conferencetype]]國際[[conferencedate]]20120305~20120308[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Kyoto, Japa

Mathematical modelling of the rotary engine

The rotary engine of the Wankel type is currently undergoing a renaissance in the combustion engine industry, mainly because of the simplicity of its design and high power to weight ratio. Strong reliability increases the demand in the aero industry where it is used mainly in small aircrafts such as drones. In the engine development process, there is a high demand for 1 dimensional (1D) simulation software which reduces the time of the development. The commercially available software provides a possibility of predicting the performance of the piston-reciprocating engine to a very high level of accuracy given initial conditions. As the demand for the rotary engines isn’t comparable to the piston-reciprocating engines, currently commercially available software doesn’t include the required equations for the rotary engine prediction calculations. This paper includes an approach for design of the virtual comparable piston engine, that can be used as an initial data source for the calculation of the rotary engine using commercially available software

Cost and Performance of Automotive Emission Control Technologies

The problem at hand is to investigate the near-term commercial feasibility of a wide range of automotive emission control technologies. The central issues can best be explained in terms of the emission control characteristics of each technology and their costs. Governmentally established emission control standards may be viewed as constraints on the use of a given vehicle and engine design. Either the technology meets the standard in use or it will not be sold. Emission control technologies that show promise of near-term manufacturability will be identified. Then, without presuming what future emission standards will be, the emission characteristics of example vehicle-engine combinations will be listed. Technologies that are acceptable, given a specified emission standard, can then be identified by a process of elimination. The approach to identifying the relevant costs associated with a given technology is not as clear cut. One would like to think that the most basic question governing the adoption of a given feasible technology is, "Will it be purchased by the public?" The second part of this paper will discuss the impact of pollution control technology on the economic decisions facing the new car customer. The cost considered by the rational new car consumer involves more than first cost. Other important factors include maintenance, operating expenses, resale value, and financing charges. Since resale value and financing charges are highly time dependent, it is possible that a new car purchaser's decision on which technology to buy may depend on how long he plans to keep the car. A cost annualization procedure will thus be developed which considers these factors

Computational experience with a three-dimensional rotary engine combustion model

A new computer code was developed to analyze the chemically reactive flow and spray combustion processes occurring inside a stratified-charge rotary engine. Mathematical and numerical details of the new code were recently described by the present authors. The results are presented of limited, initial computational trials as a first step in a long-term assessment/validation process. The engine configuration studied was chosen to approximate existing rotary engine flow visualization and hot firing test rigs. Typical results include: (1) pressure and temperature histories, (2) torque generated by the nonuniform pressure distribution within the chamber, (3) energy release rates, and (4) various flow-related phenomena. These are discussed and compared with other predictions reported in the literature. The adequacy or need for improvement in the spray/combustion models and the need for incorporating an appropriate turbulence model are also discussed

Hybrid propulsion system with a gyro component for economic and dynamic operation

The design of a hybrid drive with gyro components is described and its drive components for a medium class private car are discussed. The gyro component affects the short-period output of the drive by accelerating and slowing down and -- because of the mechanical transfer of kinetic energy between the gyro and the vehicle -- it affects also the energy balance in the case of intermittent operation. Energy can be taken in as desired either in the form of fuel or as fuel and current. A high energy recovery efficiency as well as the favorable operating range of the interval combustion engine makes it possible to reduce the fuel consumption per unit distance travelled to almost half that for a private car with a traditional engine

Getting out of the vicious traffic circle: attemps at restructuring the cultural ambience of the automobile throughout the 20th century

For years, alternative vehicle and propulsion concepts have had a very difficult time catching on, even though technicians and engineers have repeatedly pointed out that the design quality of electric propulsion systems or other novel vehicle concepts is available and feasible. Often enough, this state of affairs allowed free rein for various conspiracy theories, in which extraneous issues were made responsible for the lack of technological breakthrough. This paper agues, however, that innovation research has itself focused too narrowly on the process of the establishment of new products. On the basis of five case examples —the implementation of diesel engine propulsion for street vehicles; the EV1, the first electrically propelled standard car by General Motors; Ford’s prototype electric car study “Pivco”; the NSU Wankel engine; and the “Smart” car manufactured by DaimlerChrysler — an attempt is made to develop a comprehensive understanding of innovation processes which does not stop at the “technical invention” of a device. The thesis is that a new device requires a relevant cultural ambience, which must be more or less invented alongside it in multiple dimensions. Technical-constructive work is thus only one part of a successful innovation process; parallel to this, complementary measures must be taken with regard to the overall sectoral environment, law-making, user perceptions and attributions of meaning, as well as the cultural appropriation of a given device. Without the appropriate “adaptive measures”, even the most interesting technical projects runs the risk of sinking onto oblivion for lack of relevance. -- Alternative Antriebs- und Fahrzeugkonzepte tun sich in der Durchsetzung schon seit Jahren sehr schwer, obwohl immer wieder von Technikern und Ingenieuren darauf verwiesen wird, dass die konstruktive Qualität von elektrischen Antriebssystemen oder anderen neuartigen Fahrzeugkonzepten vorhanden sei. Oft genug konnten daher Verschwörungstheorien Raum greifen, in denen sachfremde Tatbestände für die fehlenden technischen Durchbrüche verantwortlich gemacht wurden. Im vorliegenden Beitrag wird argumentiert, dass die Innovationsforschung selbst einen zu engen Blick auf die Prozesse der Etablierung neuer Produkte eingenommen hat. Anhand von fünf Fallbeispielen, der Durchsetzung des dieselmotorischen Antriebes für Strassenfahrzeuge, des EV1, des ersten elektrisch betriebenen Serienfahrzeuges von General Motors, der Konzeptstudie Pivco, einem Elektroautomobilprojekt des Ford-Konzerns, des NSU-Wankelmotors sowie des neuartigen Fahrzeugkonzeptes Smart wird hingegen versucht, ein umfassendes Verständnis von Innovationsprozessen zu entwickeln, das nicht bei der technischen Erfindung eines Gerätes halt macht. Die These ist, dass neue Geräte zur Durchsetzung am Markt auch einen entsprechenden Funktionsraum benötigen (cultural ambience), der mehrdimensional sozusagen immer gleich miterfunden werden muss. Die technisch-konstruktive Arbeit ist daher nur ein Teilbereich eines erfolgreichen Innovationsprozesses. Parallel müssen weitere Vorkehrungen im Branchenumfeld, bei der Gesetzgebung, bei den Nutzerperzeptionen und Bedeutungszuschreibungen sowie den kulturellen Aneignungsweisen vorgenommen werden. Ohne die entsprechenden Anpassungsmassnahmen droht auch den interessantesten technischen Projekten aus Mangel an Relevanz die Bedeutungslosigkeit.

Hybrid propulsion systems for motor vehicles with predominantly intermittent modes of operation

A small delivery vehicle was equipped with a flywheel-hybrid drive and compared in test stand and driving tests with a conventional drive vehicle. It turned out that with the hybrid drive, energy can be saved and exhaust emissions can be reduced

Adiabatic Wankel type rotary engine

This SBIR Phase program accomplished the objective of advancing the technology of the Wankel type rotary engine for aircraft applications through the use of adiabatic engine technology. Based on the results of this program, technology is in place to provide a rotor and side and intermediate housings with thermal barrier coatings. A detailed cycle analysis of the NASA 1007R Direct Injection Stratified Charge (DISC) rotary engine was performed which concluded that applying thermal barrier coatings to the rotor should be successful and that it was unlikely that the rotor housing could be successfully run with thermal barrier coatings as the thermal stresses were extensive

A two-dimensional numerical study of the flow inside the combustion chambers of a motored rotary engine

A numerical study was performed to investigate the unsteady, multidimensional flow inside the combustion chambers of an idealized, two-dimensional, rotary engine under motored conditions. The numerical study was based on the time-dependent, two-dimensional, density-weighted, ensemble-averaged conservation equations of mass, species, momentum, and total energy valid for two-component ideal gas mixtures. The ensemble-averaged conservation equations were closed by a K-epsilon model of turbulence. This K-epsilon model of turbulence was modified to account for some of the effects of compressibility, streamline curvature, low-Reynolds number, and preferential stress dissipation. Numerical solutions to the conservation equations were obtained by the highly efficient implicit-factored method of Beam and Warming. The grid system needed to obtain solutions were generated by an algebraic grid generation technique based on transfinite interpolation. Results of the numerical study are presented in graphical form illustrating the flow patterns during intake, compression, gaseous fuel injection, expansion, and exhaust

Photo-driven Molecular Wankel Engine B13+_{13}^+

We report a molecular Wankel motor, the dual-ring structure B13+, driven by circularly-polarized infrared electromagnetic radiation, under which a guided uni-directional rotation of the outer ring is achieved with rotational frequency of the order of 300 MHz.Comment: 5 pages, 4 figure