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Vehicular Engines
Published in G. K. Awari, V. S. Kumbhar, R. B. Tirpude, Automotive Systems, 2021
G. K. Awari, V. S. Kumbhar, R. B. Tirpude
There are three types of superchargers in use:Centrifugal typeIn this type, the impeller rotates in a closed casing. It operates on the principle of centrifugal force. Due to centrifugal action, the pressure of inlet air increases. Considerable quantity of air can be delivered by relatively small size of centrifugal type superchargers.Roots typeIt consists of two cylindrical lobes rotating in opposite directions, and in same casing. One rotor is connected to the other by gears so both rotors rotate at the same speed. The roots blower operates on the principle of gear pump. The mixture supplied to the outlet has more pressure compared to the inlet mixture.Vane typeIt consist of a drum on which a number of vanes mounted enclosed in a casing. Against the spring force, the vanes slide in and out and maintain continuous contact with the body. The space between the drum and the inner surface of the body decreases from the inlet to the outer side of the body. The quantity of air which enters at the inlet decreases in volume, which increases outlet pressure.
Internal Combustion Engines
Published in D. Yogi Goswami, Frank Kreith, Energy Conversion, 2017
David E. Klett, Elsayed M. Afify, Kalyan K. Srinivasan, Timothy J. Jacobs
Two types of superchargers are in use: the positive displacement type (Roots blower) and the centrifugal type. Roots blowers may be classified as: (1) straight double lobe; (2) straight triple lobe; and (3) helix triple lobe (twisted 60%). The helix triple-lobe type runs more quietly than the others and is generally recommended, especially for Diesel engines operating under high torque at various speed conditions. Because of its high capacity and small weight and size, the centrifugal type is best suited for applications in which power and volumetric efficiency improvement are required at high engine speed, e.g., with aircraft engines. A centrifugal blower will also survive a backfire more readily than a Roots blower in SI applications. Because superchargers are directly driven from the engine output shaft, no inherent lag in the rate of pressure increase with engine speed is present, as is typically the case with turbochargers.
Engine performance
Published in Mohammad H. Sadraey, Aircraft Performance, 2017
It is beneficial to compare the features of a supercharger with a turbocharger. In general, superchargers maintain three advantages over turbochargers: (1) smaller size, (2) requires less piping, and (3) does not require high-temperature materials in the turbine. A supercharger requires some energy to be extracted from the engine. For instance, on the supercharged Rolls-Royce Merlin engine, the supercharger uses up to about 150 hp. However, the benefits outweigh the costs. The engine delivers 1000 hp when it would otherwise deliver 750 hp, an increase of 250 hp. However, a turbocharger is driven using the exhaust gases. The amount of power in the gas is proportional to the difference between the exhaust pressure and outside pressure, and this difference increases with altitude, thus allowing a turbocharger to compensate for changing altitude.
NOx emission control strategies in hydrogen fuelled automobile engines
Published in Australian Journal of Mechanical Engineering, 2022
Sirajuddin Syed, Manimaran Renganathan
Due to the wide range applicability of turbochargers and superchargers, they are commonly used in real engine applications. Both the devices work on same principle by improvingthe intake pressure of charge entering into the combustion chamber (Willard 2013; Heywood 1988). This increases the charge density which results in increased engine performance. Addition of turbocharger or supercharger to the engine increases the supply of air. This improves the combustion and favours the formation of higher in-cylinder temperatures. This results in increased performance and NOx emissions of engine till the speed range of 1600–1800 rpm. With the further increase of speed, the high fuel/air ratio and poor oxygen are not favourable for the formation of NOx (Jiaqiang et al. 2019; Luo et al. 2019; Lee et al. 2019). Effect of turbocharging and supercharging on the emissions of the CI engine is explored and presented here (Liu et al. 2016; Kitabatake, Shimazaki, and Nishimura 2007; Kitamura et al. 2005).
Effect of pilot injection timing using crude palm oil biodiesel on combustion process on dual fuel engines with compressed natural gas as the main fuel
Published in International Journal of Sustainable Engineering, 2021
Bambang Sudarmanta, Dori Yuvenda, Ary Bachtiar K.P., Arif Wahjudi, Ahmad Arbi Trihatmojo
The engine used is a direct injection diesel engine, four stroke, one cylinder, naturally aspirated. The engine has a compression ratio of 18: 1. The standard diesel injection timing is 13° BTDC. The details of the engine specifications are described in Table 2. The diesel engine is modified to a dual fuel (DF) engine using CNG fuel and CPO biodiesel. CNG fuel acts as the main fuel and CPO biodiesel fuel acts as pilot fuel. The DF engine is also equipped with an electric supercharger in order to forcibly add combustion air to lower the equivalent ratio value that has been studied from previous studies (Trihatmojo, Yuvenda, and Sudarmanta 2019). The DF engine is also coupled with an electric generator as a simulation of engine load using lights.
Sensitivity of light duty vehicle tailpipe emission rates from simplified portable emission measurement systems to variation in engine volumetric efficiency
Published in Journal of the Air & Waste Management Association, 2021
Tongchuan Wei, H. Christopher Frey
LDGVs dominate the on-road vehicle fleet in the U.S. and China, and the share of LDGVs in the European Union has increased in the last decade (Davis and Boundy 2020; International Council on Clean Transportation 2020). In 2019, 252 million light-duty vehicles (LDVs) comprised 91% of the U.S. on-road vehicle fleet (Federal Highway Administration 2020). About 98% of U.S. LDVs are LDGVs (EPA, 2021). In China, the proportion of LDGVs to LDVs is similar to that in the U.S. (Davis and Boundy 2020). In the 2018 model year, naturally-aspirated LDGVs in the U.S. and China comprised about 70% of the new LDGV sales (ResearchInChina 2019; EPA, 2019). Naturally-aspirated LDGVs are LDGVs that have naturally-aspirated engines. Natural aspiration is a system of intake air delivery to the cylinders that depends only on atmospheric pressure and is not boosted through a turbocharger or supercharger (Heywood 2018). In the European Union, the share of LDGVs among the LDVs has increased from 43% to 64% between 2012 and 2019 (International Council on Clean Transportation 2020).