Dissertations / Theses on the topic 'Supercharger'

There is a growing recognition worldwide of the need for more powerful, smaller petrol engines, capable of delivering the higher picking power of larger engines, yet still being economical and environmentally friendly when used for day-to-day driving. An engineering solution for more efficient engines has been considered by research so far. It has been identified that superchargers can potentially improve the performance of automotive engines; therefore research has focused on developing superchargers and supercharger components with higher efficiency. Of particular interest to the research presented in this thesis has been the twin-screw supercharging compressor with design adapted for automotive use (the twin-screw supercharger). The performance of this supercharger type depends on the volume and total losses of the air flow through the supercharger rotors more than on any other aspects of its behaviour. To accurately predict the efficiency of the twin-screw su percharger for matching a particular engine system, accurate supercharger design is required. The main objective of this research was the investigation of the existing limitations of twin-screw superchargers, in particular leakage and reduced efficiency, leading to the development of optimal asymmetric rotor profiles. This research has been completed in four stages defining an innovative rotor design method. The parametric three-dimensional geometric model of twin-screw supercharger rotors of any aspect ratio was developed. For model validation through visualisation, CAD rotor models with scalable data were generated in commercial CAD software and calibrated experimentally by Laser Doppler Velocimetry (LDV) tests. Calibrated rotor profile data can be transferred into CAD-CFD interface for flow simulation and performance optimisation. Through the application of this new rotor design method, new opportunities are created for the twin-screw supercharger design practice, making it a part of the engineering solution for more efficient engines.

Questa tesi di laurea nasce dall’esperienza maturata presso l’azienda FCA Italy (Fiat Chrysler Automobiles S.p.A., ex VM Motori) nello stabilimento situato a Cento in provincia di Ferrara, in particolare all’interno dell’ufficio di Ricerca Avanzata CRM (Centro Ricerca Motori), divisione del reparto R&D (Research and Development). Tale esperienza viene riassunta (in piccola parte) in questo elaborato di Tesi, che tratta tematiche inerenti allo sviluppo di un sistema di sovralimentazione assistito elettricamente, applicato ad un propulsore Diesel 3.0L V6 destinato ai segmenti “Premium” del mercato. Il sistema utilizzato, che ha come componente principale un compressore attuato da una macchina elettrica, appartiene all’insieme delle tecnologie cosiddette di e-boosting. Questo tipo di tecnologia, fortemente innovativa e ad oggi non ancora presente sul mercato, ha le potenzialità per rappresentare un significativo passo avanti nel processo di riduzione delle emissioni, dei consumi e del miglioramento delle performance dei moderni motori endotermici alternativi, al punto che un numero crescente di costruttori di motori sta oggi studiando soluzioni come quella oggetto di questo elaborato. L’obiettivo è stato quindi quello di definire, applicare e gestire il sistema di e-boost a banco motore e, successivamente, caratterizzarlo dal punto di vista energetico e testarne le effettive potenzialità. Le fasi in cui ho apportato il mio contributo sono state, in particolare, quelle di definizione e integrazione dei nuovi componenti all’interno del layout motore preesistente, di realizzazione e implementazione delle strategie di controllo in un sistema dedicato in grado di gestire efficacemente i componenti, e di sperimentazione al banco prova. I risultati conseguiti al termine dell’attività sono quindi inerenti allo sviluppo e validazione del sistema di controllo, alla valutazione delle performance del propulsore risultante e alla caratterizzazione e analisi critica del sistema di e-boost dal punto di vista energetico.

The diploma thesis deals with the selection of an eligible supercharger for cooperation with the internal combustion SI engine Honda K20A2. The first part is dedicated to the research referring to an issue of charging and a brief description of particular supercharger types. However, the main part of the thesis consists in the formation of proposal calculation and the tentative choice of the eligible type of supercharger. The part of the work is also the description of the assigned engine and the measurement of its parameters. The most extensive part of the thesis deals with the making of computational model of the atmospheric and supercharged version of the engine and the consecutive simulations in the GT-Power software. Finally, gained results are evaluated and the computational study of the cooperation of the selected supercharger with assigned combustion engine is made in the last part of the diploma thesis.

The work deals with the analysis of various possibilities of increasing the efficiency of a small internal combustion engine potentially usable for use in the field of autonomous devices of smaller dimensions. It contains an outline of the problems of modern smaller autonomous means and an analysis of available drives designed for them, especially an analysis of propulsion by internal combustion engines. In his next part of the work he provides information about the created mathematical model of the demonstration internal combustion engine in the GT-Power program and an analysis of places where and in what ways its efficiency can be increased. The design of two such components together with the evaluation of the achieved results offers the conclusion of this work.

車両の電動化(ハイブリッド化)と内燃機関システムの電動化を最適に組み合わせた技術と、それらを効果的に稼働させるハイブリッド制御ロジックを適用した新方式大型ハイブリッドトラックを提案した。長距離貨物輸送時の燃料消費率の改善に対し効果があることを明らかとした。同時に、従来大型トラックに対し、荷室搭載性の確保や車両コストの抑制が可能となることが分かり、実用性の面でも優位性があることを示した。
博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University

Delivery of macromolecules into mammalian cells in vitro and in vivo has enabled new areas of research and offers the potential for powerful new treatment options. Recent research has generated many delivery platforms but these solutions remain limited by scope, potency and safety. We have reported a superpositively charged green fluorescent protein (+36 GFP) with the ability to deliver nucleic acids into a variety of mammalian cell lines in vitro and to potently deliver protein in vitro and in vivo without toxicity. These results have directed us to identify a subset of naturally occurring human proteins with similar but previously unknown cell-penetrating and protein delivery properties. Preliminary efforts have been made towards establishing the therapeutic potential for supercharged proteins replacement of the cytosolic enzyme, argininosuccinate synthase. Preliminary efforts have also been made towards enhancing endosomal escape with \(His_{39} GFP\).

The ever-changing demands from consumers for more fuel efficient vehicles necessitates automotive manufacturers developing ever more radical proposals for engine design. The latest trend from manufacturers is engine ”downsizing”; where a smaller, more efficient, engine is pressure-charged to recoup the lost full-load performance. An effect of downsizing is that engines now run at significant intake pressures. Additionally, implementation of simulation techniques as an integral part of the research and design process is becoming commonplace in the automotive industry. Whether or not current models can be considered reliable for combustion prediction at significantly elevated pressures, such as those experienced by downsized engines, is a main focus of the current work, predominantly assessed through how the crank-resolved in-cylinder pressure traces from prediction, compare to experiment. Experimental data was provided by four different engines: two Jaguar Land Rover multi-cylinder engines, one naturally aspirated, the other heavily downsized, and two University of Leeds bespoke research engines operating under naturally aspirated, or high pressure conditions representative of downsized engines. It was seen that the combustion models were not able to accurately predict combustion at different pressures without adjustment of the turbulence quantities, namely the length scale used to define the ”after-burning” process. Additionally, it is known that variability of combustion limits the performance of engines significantly; a better understanding of variability which may lead to mitigation methods would result in significant efficiency gains. The magnitude of variability in the four different engines is investigated in this work as well as the current capability in predicting the variability. Once a mean cycle was successfully matched, the variability of the engine cycles is accurately predicted for all engines and conditions by a random-number model, invoking variability on two parameters, u0 and �, with Gaussian distribution. Moreover a novel method for assessing variability is proposed and is employed in a study to assess the influence of combustion variability at different stages of combustion. The variability of the combustion event was seen to be a strong function of the very early stages of combustion. The propensity for autoignition is also known to increase with operating pressure and temperature. The predictive capability, of two autoignition models, was assessed against experimental data. It was observed that a chemical kinetic based autoignition model was more able to predict autoignition over all engines, vis-´a-vis an empirically based model. In addition, it was also seen that a variability of autoignition within the engine existed, which was independent of burning rate. Finally, ”knocking” cycles were identified within the heavily supercharged, multi-cylinder research engine which defined the calibration limit of the engine. It was seen, however, that the frequency of pressure oscillations was beyond that traditionally seen for knock cycles.

Thesis (MScEng)--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: To reduce exhaust gas emissions in diesel engines and for engine upgrade purposes the major parameters and equipment that should be looked at are boost pressure, intake charge temperature, combustion chamber design and fuel injection equipment. Boost pressure is governed by the turbo-charger; with high-efficiency variable geometry turbochargers, effective control is possible to increase airflow rate at all operating conditions of the engine. Efficient air-to-air inter-cooling results in the engine being filled with a cooler air charge that will influence engine durability and heat rejection to the cooling system. The main objective of the investigation is to look at the influence of boost pressure and intake charge temperature on diesel combustion to better understand the processes where boost pressure is increased and intake charge temperature reduced to increase the brake mean effective pressure of the engine and reduce emissions generation. By running an engine at different intake boost pressures and intake charge temperatures a 25-point matrix was formed at three different operating conditions. On completion of the engine testing, data processing and data evaluation, a number of important conclusions were made about the behaviour of the engine running under different conditions. This enabled the researcher to understand how boost pressure and intake charge temperature influence engine power output, fuel consumption, engine durability and exhaust gas emissions. The opinion is proved when, in most cases, the 75 test points were used to build multiple linear regression models to determine which engine parameters (dependent variables) have a significant effect on emissions generation and durability parameters. From the data it is evident that boost pressure has a positive influence on most engine parameters, as an increase in boost pressure results in an increase in air mass flow through the engine. An increase in air mass flow reduces combustion chamber gas temperature as the result of an increase in excess air ratio during combustion. A further result of the increase in excess air ratio is that less soot is formed during the first part of combustion and more soot and partly decomposed Hydrocarbon (HC) compounds are oxidised during the late combustion phase. Therefore, with an increase in boost pressure, Bosch smoke emissions reduce, but with a change in intake air temperature no difference in smoke concentration is seen except at the very low boost pressure and very high boost temperature test points where low air/fuel ratios exist and the slight increase in air-flow rate as a result of lower air inlet temperature has a big influence. Nitric Oxide (NO) emissions, on the other hand, are more dependent on intake air temperature than on boost pressure, which was proved in the multiple regressions modelling performed on the test data. The flame zone and the post-flame zone temperature play the dominant role in NO formation. As explained in the results discussion on NO formation, intake air temperature influences the ignition mixture temperature and the subsequent flame zone temperature. A lower intake air condition results in longer ignition delay and increases the initial rate of combustion.
AFRIKAANSE OPSOMMING: Die hoofparameters en toerusting wat in ag geneem moet word om uitlaatgasemissies in dieselenjins te verminder en om enjinkraguitset te verhoog, is inlaatdruk, inlaat lugtemperatuur, verbrandingskamerontwerp en brandstofinspuittoerusting. Inlaatdruk word beheer deur die turb-aanjaer. Met hoë effektiwiteit, veranderlike geometrie turboaanjaging, is effektiewe beheer moontlik om lugvloei-tempo deur die enjin te verhoog onder alle enjinwerkstoestande. Effektiewe lug-tot-lug tussenverkoeling laat die enjin met koeler inlaatlug vul, wat 'n uitwerking het op enjinlewensduur en hitte-verlies na die verkoelingsstelsel. Die hoofdoel van die navorsing is om die invloed van inlaatdruk en inlaat lugtemperatuur op dieselverbranding te ondersoek. Sodoende kry die navorser 'n beter begrip omtrent die prosesse waar inlaatdruk verhoog en inlaat lugtemperatuur verlaag word, om rem-gemiddelde effektiewe druk van die enjin te verhoog en uitlaatgas emissies te verlaag. 'n 25-punt matriks is opgestel deur die enjin by verskillende inlaatdrukke en inlaat lugtemperture te opereer, en by drie verskillende wringkragwerkstoestande. 'n Aantal belangrike gevolgtrekkings is gemaak omtrent enjinwerking onder verskillende werkstoestande na voltooiing van die enjintoetse, dataverwerking en data-evaluering. Sodoende het die navorser bepaal hoe inlaatdruk en inlaat lugtemperatuur kraglewering, brandstofverbruik, enjinlewensduur en uitlaatgasemissies beïnvloed. Om bogenoemde begrippe verder te ondersteun is 'n meervoudige, lineëre regressiemodel opgestel om te bepaal watter enjinparameters (afhanklike veranderlikes) 'n wesenlike effek op emissiegenerasie en lewensduur het. Van die data word afgelei dat inlaatdruk 'n positiewe effek op die meeste enjinparameters het, omdat hoër inlaatdruk die lugvloeitempo deur die enjin verhoog. Hoër lugmassavloei verminder verbrandingsgastemperatuur as gevolg van 'n hoër oortollige lugverhouding tydens verbranding. 'n Verdere gevolg van 'n hoër oortollige lugverhouding is dat minder roet gevorm word gedurende die eerste verbrandingsfase en meer roet en gedeeltelik verbrande koolwaterstofverbindings oksideer gedurende die finale verbrandingsfase. Dus, met 'n hoër inlaatdruk word Bosch rookemmissies verlaag. Geen wesenlike verandering in rookkonsentrasies word egter gesien met 'n verandering in inlaatlugtemperatuur nie, behalwe by baie lae inlaatdruk- en hoë inlaat lugtemperatuur-toetskondisies waar lae lug/brandstofverhoudings bestaan en 'n klein toename in lugmassavloei as gevolg van laer inlaat lugtempertuur'n groot invloed het. Stikstofmonoksied (NO) emissies is meer afhanklik van inlaat lugtemperatuur as inlaatdruk. Dit is bewys in die meervoudige regressiemodel. Die vlamsone- en die navlamsone- temperatuur speel 'n groot rol in NO vorming. Inlaat lugtemperatuur beïnvloed die temperatuur van die onstekingsmengsel en die daaropvolgende vlamsonetemperatuur. 'n Laer inlaat lugtemperatuur veroorsaak 'n langer onstekingsvertraging en verhoog die aanvanklike verbrandingstempo.

As a class, protein-based therapeutics offer tremendous advantages over traditional small molecule drugs. Due to their sizes and folding energies, proteins are ideal for catalyzing chemical reactions, and can bind tightly and selectively to extended target surfaces. However, due to their large size, virtually all proteins are unable to spontaneously enter cells, and as a result protein therapeutics are restricted to extracellular targets. We developed a platform for delivery of proteins to intracellular target sites by engineering the surface chemistry of a model protein, green fluorescent protein (GFP). We found that 'supercharged' cationic GFP variants (scGFPs) bind to anionic cell surface molecules and initiate endocytosis, resulting in the efficient delivery of translationally fused cargo to intracellular targets. We discovered that scGFPs, and cationic delivery reagents in general, alter endosomal trafficking in a manner proportional to both their charge and their delivery efficiency, suggesting that avoidance of endosomal maturation is a key step in the endosomal escape of delivered protein cargos. We also developed a method for encapsulation of recombinant proteins by cationic lipid delivery reagents using negatively supercharged GFP. Genetic modification technologies have matured rapidly following the discovery of protein classes with programmable DNA-binding specificities. While site-directed genetic knockout technologies are highly effective, targeted integration and repair remain comparatively inefficient. Site-specific recombinases directly catalyze strand exchange and ligation between DNA molecules, offering an approach to efficient genomic integration. However, most site-specific recombinases are not easily reprogrammable. To address this problem, we developed a genetic selection technique based on the Phage-Assisted Continuous Evolution (PACE) system, to enable the rapid evolution of recombinase proteins towards targets of interest. Using Cre recombinase as a model, the PACE system was optimized, validated, and used to evolve Cre variants with higher activity on their native loxP target site, as well as altered specificity towards a human genomic sequence within the hROSA26 locus. Finally, we developed a method for enhancing the specificity of RNA-guided nucleases by restricting activity to sites of obligate dimeric nuclease assembly. We engineered a FokI nuclease fusion to a catalytically inactivated Cas9 protein that mediates efficient modification with significantly reduced off-target activity.

A content of this diploma thesis is construction design of torsional vibration rubber damper of four-stroke diesel supercharged engine. It` s realized evaluation of crankshaft from aspect of torsional vibrations and checked mechanical stress of crankshaft without using rubber damper. Consequently basic parameters of rubber damper are specified, then checked mechanical stress of crankshaft and designed own construction design of damper.

Les interactions non-covalentes (NCI pour Non-Covalent Interactions) stabilisant les complexes non-covalents biologiques (NCX pour Non-Covalent compleXes) régissent la majorité des processus cellulaires indispensables au développement et au bon fonctionnement de tout organisme vivant. Toutes les fonctions de l'ADN, tels que son conditionnement, sa réplication et la régulation de son expression, sont permises par la formation et la dissociation de NCI avec des protéines. La compréhension des bases de ces processus cellulaires de l'ADN au niveau moléculaire est un sujet d'actualité et d'une importance fondamentale. Des informations essentielles peuvent être obtenues par spectrométrie de masse (MS pour Mass Spectrometry) qui joue un rôle de plus en plus important dans ce domaine. Malgré la technologie avancée déjà mise en ¿uvre, le développement de nouveaux concepts d'ionisation et d'activation implémentent perpétuellement la MS. Les travaux de thèse exposés à travers ce manuscrit présente l'étude de la stabilité des NCI maintenant les NCX biologiques par la comparaison des voies de fragmentations observées en mode positif et en mode négatif mais aussi par l'application de certains concepts récents de la MS comme : (i) l'utilisation d'agents de " superchargement " et, (ii) le développement et l'utilisation d'une source V-EASI (pour Venturi Easy Ambiant Sonic-spray Ionization) permettant l'aspiration libre de la solution et la désorption/ionisation des analytes par la seule vélocité du gaz de nébulisation.

This thesis discusses of the intake tract four-stroke ignition internal combustion engine and the filling efficiency and opportunities to increase this efficiency and consequently to optimize the course of torque and power at the specified serial engine. 3D model is the last point of this thesis.

Recent efforts to classify off-shell representations of supersymmetry without a central charge have focused upon directed, supermultiplet graphs of hypercubic topology known as Adinkras. These encodings of Super Poincare algebras, depict every generator of a chosen supersymmetry as a node-pair transformtion between fermionic / bosonic component fields. This research thesis is a culmination of investigating novel diagrammatic sums of gauge quotients by supersymmetric images of other Adinkras, and the correlated building of field theoretic worldline Lagrangians to accommodate both classical and quantum venues. We find Ref [40], that such gauge quotients do not yield other stand alone or ”proper” Adinkras as afore sighted, nor can they be decomposed into supermultiplet sums, but are rather a connected ”Adinkraic network”. Their iteration, analogous to Weyl's construction for producing all finite-dimensional unitary representations in Lie algebras, sets off chains of algebraic paradigms in discrete-graph and continuous-field variables, the links of which feature distinct, supersymmetric Lagrangian templates. Collectively, these Adiankraic series air new symbolic genera for equation to phase moments in Feynman path integrals. Guided in this light, we proceed by constructing Lagrangians actions for the N = 3 supermultiplet YI /(iDI X) for I = 1, 2, 3, where YI and X are standard, Salam-Strathdee superfields: YI fermionic and X bosonic. The system, bilinear in the component fields exhibits a total of thirteen free parameters, seven of which specify Zeeman-like coupling to external background (magnetic) fluxes. All but special subsets of this parameter space describe aperiodic oscillatory responses, some of which are found to be surprisingly controlled by the golden ratio, ? ? 1.61803, Ref [52]. It is further determined that these Lagrangians allow an N = 3 ? 4 supersymmetric extension to the Chiral-Chiral and Chiral-twisted- Chiral multiplet, while a subset admits two inequivalent such extensions. In a natural progression, a continuum of observably and usefully inequivalent, finite-dimensional off-shell representations of worldline N = 4 extended supersymmetry are explored, that are variate from one another but in the value of a tuning parameter, Ref [53]. Their dynamics turns out to be nontrivial already when restricting to just bilinear Lagrangians. In particular, we find a 34-parameter family of bilinear Lagrangians that couple two differently tuned supermultiplets to each other and to external magnetic fluxes, where the explicit parameter dependence is unremovable by any field redefinition and is therefore observable. This offers the evaluation of X-phase sensitive, off-shell path integrals with promising correlations to group product decompositions and to deriving source emergences of higher-order background flux-forms on 2-dimensional manifolds, the stacks of which comprise space-time volumes. Application to nonlinear sigma models would naturally follow, having potential use in M- and F- string theories.
Ph.D.
Doctorate
Physics
Sciences
Physics

Thesis (M.S.)--University of Wisconsin--Madison, 2002.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 109-110).

碩士
國立臺北科技大學
車輛工程系碩士班
91
This study is made by experimental method for the purpose of improving the performance of mechanical centrifugal supercharger at low rotational speed in SI engine. The airflow quantity, compression and volume efficiency of mechanical centrifugal supercharger are reached more higher at higher engine speed range. In high-pressure ratio condition, the impeller and the volute casing are so difficult to seal completely that would increase leakage and decrease air flow quantity, compression and volume efficiency. However the maximum efficiency of supercharger will appear at lower pressure ratio. Besides higher rotational speed and pressure ratio make more difference in temperature between the inlet and outlet of the supercharger. At first, the MITSUBISHI 4G92 1600c.c. engine affords more stable power source of driving the supercharger unit and with which we build an apparatus of performance of the mechanical centrifugal supercharger to realize the information of supercharger capacity. Such as airflow rate, pressure ratio, increasing temperature and velocity of air flow in duct under different engine rotational speed and degree of throttle valve. According to the above information to estimate and equip the engine system of supercharger, that is measured the performance of engine power, airflow rate and different temperature between the inlet and outlet of the supercharger, comparing with natural aspirated engine situation. Meanwhile, the result is supported to improve the performance of mechanical centrifugal supercharge and to arrange with a mechanical centrifugal supercharge of engine. Referring to the experimental result, we figure out the performance of the horsepower, torque, pressure and air flow rate that is not increased outstandingly at low rotational speed area below 2000 rpm. Under WOT situation; when rotational speed reaches 2000 rpm horsepower increases 4.47% and torque increases 4.45% comparing with natural aspirated engine. Henceforth accompanies with engine rotational speed rising the torque and horsepower produced by the supercharged engine also increasing. When rotational speed reaches 5000 rpm horsepower increases 22.66% and torque increases 22.70% to attain maximum. The pressure in the duct of natural aspirated engine wills all maintain below atmospheric pressure condition. And accompanies with engine rotational speed to increase its pressure decreasing. For supercharged engine at the whole rotational speed scope all is keeping at higher than atmospheric pressure. Furthermore, the pressure and the airflow rate of duct of supercharged engine will increase with the engine speed under vary engine revolution. The quantity of supercharged airflow increases not obviously at low rotational speed area comparing with natural aspirated engine.

Indiana University-Purdue University Indianapolis (IUPUI)
Pressure wave supercharger is an application of wave rotor technology that utilizes compression waves produced by high-pressure engine exhaust gas to compress the fresh intake air within the channels. The phenomena within the wave rotor channels are governed by compression and expansion waves initiated when the channel ends are periodically exposed to differing pressure ports. Two incoming fluids are brought into contact for a very short amount of time to facilitate efficient energy and momentum transfer, thereby exchanging pressure dynamically between the fluids by means of unsteady pressure waves. Since the energy transfer is based on unsteady pressure waves, correct matching of waves and ports is essential for optimum results. Mistiming of the waves in the channels is detrimental to the efficient exchange of pressure and low-pressure exhaust scavenging, which ensures minimum exhaust gas recirculation. Due to varying speed and load conditions of the unit to be supercharged, it is not always possible to maintain the rotor speed constant at the design point. To mitigate the effects of wave mistiming due to varying speed, a well-designed combination of wall-pockets was used in Comprex® pressure wave supercharger. The wall-pockets are the recesses provided in the endplates of pressure wave superchargers to create necessary pressure zones at desired locations. This thesis details an extensive qualitative and computational investigation of the performance of pressure wave superchargers with pockets. Numerical simulations of pressure wave superchargers have been performed using the wave rotor analysis codes employed at the Combustion and Propulsion Research Laboratory at IUPUI. This work also pays close attention to inspecting the numerical schemes and modeling of different physical phenomena used in each code. A comparative verification of the wave rotor analysis codes has been conducted to ensure that the same fundamental numerical scheme is correctly implemented in each code. The issue of low-pressure scavenging has been demonstrated by simulating the four-port (pocketless) pressure wave supercharger operating at lower speeds. The wall-pockets have been modeled using a simple lumped volume technique. The gas state in the lumped volume of pockets is estimated using the continuity and energy equations such that the net mass and energy fluxes between each pocket and the wave rotor channels are close to zero. The lumped volume models of pockets have been implemented in the four-port wave rotor configurations to simulate the pressure wave superchargers with pockets. The simulation results show that the pockets assist to maintain sufficient pressure in the desired zones to facilitate proper low-pressure scavenging during lower rotor speed operations. The Comprex simulation results have been observed to be in good agreement with experimental data and qualitative analysis. Specific observations on the performance of each code and comprehensive simulation results have been presented.

В работе проведен анализ причин повреждения рабочих колес центробежных нагнетателей, проведены сравнительные расчеты колес обычного и подрезанного типов, проанализированы результаты.
The paper analyzes the causes of damage to the impeller of centrifugal blowers, comparative calculations of wheels of conventional and clipped types, analyzed the results.

碩士
國立臺灣大學
機械工程學研究所
92
The exhaust emission of two-stroke motorcycle engine is more serious than that of four-stroke engine, so it will be eliminated. But most of 50 c.c. motorcycles use two-stroke engines. The four-stroke 50 c.c. motorcycle will have the problem of lower power output, so we have to increase the power output of the engine. About one-third of input energy of internal combustion engine is released to ambient by exhaust gas. If we use the exhaust gas of engine to drive a supercharger that will increase the performance of engine, and can further reduce the exhaust emission. By reviewing the history of supercharged internal combustion engine; we found out that almost all of supercharged methods have been developed was used for car or truck, none of them can be used for motorcycle. So designing a supercharger for motorcycles will be a subject that is worthy of studying. This research used the principle of piston motion. There is a slider in the cylinder that is separated to exhaust chamber and fresh air chamber by this slider. Two small pipes were attached at the ends of cylinder. The fresh air chamber attached to the region in front of inlet throttle, and the exhaust chamber attached to the exhaust pipe of engine. The pressure difference between two sides of slider makes the slider to move in the cylinder that can boost the fresh air in the fresh air chamber to flow into the engine cylinder. That can increase the volumetric efficiency, and hence improve the engine performance. This research used the computational fluid dynamic software “CFD-RC” to simulate the said supercharger. In the different operation condition, we analyze the supercharging pressure and the mass flow rate of this supercharger.