Search Results

This book examines the development of the engine from a historical perspective. Originally published in Japanese, The Romance of Engines' English translation offers readers insight into lessons learned throughout the engine's history. This book belongs on the bookshelves of all engine designers, engine enthusiasts, and automotive historians. Topics covered include: Newcomen's Steam Engine The Watt Steam Engine Internal Combustion Engine Nicolaus August Otto and His Engine Sadi Carnot and the Adiabatic Engine Radial Engines; Piston and Cylinder Problems Engine Life Problem of Cooling Engine Compartments Knocking; Energy Conservation Bugatti; Volkswagon Rolls Royce Packard Daimler-Benz DB601 Engine and more!

The relations of luminous intensity of the radicals, CH, C2, and OH radical, and the equivalence ratio, ϕ under high combustion pressure region (7.0MPa maximum) were investigated. Luminous intensity of each radical and combustion pressure were experimentally obtained using a constant volume combustion chamber. It was found that luminous intensity of each radical can be expressed as a function of ϕ and the combustion pressure. The estimation of ϕ was done within the region, 0.8<ϕ<1.2 and 2.0MPa

In the 17th century, Christiaan Huygens invented the first engine to save the labor, which is humanism. Nowadays, both gasoline (SI) and diesel (CI) engines hold the definite position as the prime mover of the current surface transport vehicles due to their superior power, energy density, and fuel economy. Although these engines give exceeding convenience to human life, they also have become the vanguard of environmental disruption. From this viewpoint, the author has tried to give a historical review and perspective on engine developments. Although it is said that further emission controls in CI engines are quite difficult, recent research work and prediction for both lower emissions and better fuel economy are discussed. It is concluded that CI engines will co-exist with SI engines in the future, part of which will be used in hybrid systems. Fuel cells will be widely utilized, and hydrogen internal combustion engines would be expected as well.

This study proposes a method to calculate the limit of piston ring conformability to deformed bore based on measured gas leakage flow rate through ring-bore gap and calculated gap area using a test device that allows the creation of arbitrary bore deformation. As a result, it was clarified that predicted conformability can be matched with measured value by modifying a constant value in the conformability equation for a single order bore deformation proposed by Dunaevsky and Tomanik et al. Furthermore, it has been confirmed experimentally that the conformability limit index ∑U for the complex bore deformation proposed by Tomanik is valid. Using ∑U, area of gap between piston ring and deformed bore under engine operating condition was calculated to derive the relationship between blow-by gas flow rate.

The electronic controlled carburetor and ignition system has been developed. In accordance with various working conditions of the engine, the system adjusted corresponding control parameters; air fuel ratio and ignition timing, therefore it could keep the engine working on the optimal conditions. Through analyzing overall performance of the engine based on the experimental data, we had concluded that the specific fuel consumption was improved about 8-10%, and the exhaust emission performance was improved correspondingly after electronic control, the improved ratio was about 10% for HC emission and 97% for CO emission.

The purpose of this study is to find the suitable working conditions of a Pressure Wave Supercharger (PWS) that is coupled to a gasoline engine experimentally. The working condition is validated by stationary measurements on an engine dynamometer. To achieve an easier system structure, it was examined to use the engine output for driving of PWS. As a result, it was confirmed that the engine coupled with PWS could be driven by making the ratio of the PWS rotor speed and the engine speed constant.

In order to clarify the diesel fuel spray characteristics inside the cylinder, we developed two novel techniques, which are preparation of same level of temperature and pressure ambient as inside cylinder and quantitative measurement of vapor concentration. The first one utilizes combustion-type constant-volume chamber (inner volume 110cc), which allows 5 MPa and 873K by igniting the pre-mixture (n-pentane and air) with two spark plugs. In the second technique, TMPD vapor concentration is measured by using Laser Induced Exciplex Fluorescence method (LIEF). The concentration is compensated by investigation of the influence of ambient pressure (from 3 to 5 MPa) and temperature (from 550 to 900 K) on TMPD fluorescence intensity. By using two techniques, we investigated the influence of nozzle hole diameter, injection pressure and ambient condition on spray characteristics.

Diesel engine has fuel combustion capability in various high density oil such as residual fuels or biofuels derived from fossil or living matter. But for commercial use, these fuels except bio diesel fuel (BDF) should be heated, separated and filtered by equipment and dosed or mixed with additive or distillate oil etc. before being supplied to the engine in order to improve combustibility. This study aims to illuminate fuel characteristic of blend contained woody pyrolysis oil (WPO) which is high viscosity and incombustible, and dimethyl ether (DME) whose emission of combustion has no soot particle. This paper describes thermo-physical property of neat WPO and the blend on the basis of the evaluation of fuel fluidity by measurement and calculation of viscosity. According to the result, it was confirmed that the fluidity of WPO was improved by mixing DME and the approximate viscosity expressions at any temperature of WPO and the blend were good accuracy.

In Japan, about 5.6 billion tons of freight are transported annually and 90% of this figure is supported by trucks. Among them, the heavy vehicles of GVW 20ton are employed as one of the main means of such transportation and they are produced about 40,000 units annually. For these trucks, over 80 types of diesel engines have been developed during the past 20 years. Today, there are more than 30 domestic types. The engine displacement ranges from 8.8 to 18.0 liters and the maximum output spreads from 270hp (199kW) to 380hp (280kW). The naturally aspiration type occupies 70% and the turbocharged or turbo-intercooled type takes the remaining portion. The authors present the design concept and the technical background which are involved in the above-mentioned engines. They also describe the technology which concerns combustion, gas exchange, construction, electronic control, etc. and the ‘total power system’ (some simultaneously managing system) formulated to realize such engines.

Temperature measurement experiments with intake port model were done to achieve the fundamental information on constructing physical model that expresses the heat transfer phenomena in the intake manifold and intake port. The experiments were done with steady airflow, and the size, shape, heating condition of the port model and mass flow rate were changed as experimental parameters. As the results, it was clear that the developing condition of velocity and thermal boundary layer had greater influence than the shape factor, and the coefficient and the exponent of the equation derived from the relationship between Nusselt number and Reynolds number had great difference from those of generally used Colburn's equation in undeveloped entrance region, but they got closer as developing boundary layer.

In the past two decades, internal combustion engines have been required to improve their thermal efficiency in order to limit hazardous gas emissions. For further improvement of the thermal efficiency, it is required to predict the mass of intake air into cylinders in order to control the auto-ignition timing for CI engines. For an accurate prediction of intake air mass, it is necessary to model the heat transfer phenomena at the intake manifold. From this intention, an empirical equation was developed based on Colburn equation. Two new arguments were presented in the derived formula. The first argument was the addition of Graetz number, where it characterized the entrance region thermal boundary layer development and its effect on the heat transfer inside the intake manifold. As the second argument, Strouhal number was included in order to represent intake valve effect on heat transfer.

An empirical equation was developed for modeling the heat transfer phenomena taking place in an intake manifold which included the backflow gas effect. In literature, heat transfer phenomenon at intake system is modeled based on steady flow assumptions by Colburn analogy. Previously, authors developed an equation with the introduction of Graetz and Strouhal numbers, using a port model experimental setup. In this study, to further improve the empirical equation, real engine experiments were conducted where pressure ratio between the intake manifold and engine cylinder were added along with Reynolds number to characterize the backflow gas effect on intake air temperature. Compared to the experimental data, maximum and average errors of intake air temperature estimated from the new empirical equation were found to be 2.9% and 0.9%, respectively.

Temperature distribution as the flame propagated and contacted to the wall of the combustion chamber was measured by real-time holographic interference method, which mainly consisted of an argon-ion laser and a high-speed video camera. The experiment was done with a constant volume chamber and propane-air mixture with several kinds of equivalence ratios. From the experimental results, it can be found that the temperature distribution outside the zone from the surface of the combustion chamber to 0.1mm distance could be measured by counting the number of the interference fringes, but couldn't within this zone because of lacking in the resolution of the used optical system. The experimental results show that the temperature distribution when the heat flux on the wall increases rapidly and when the heat flux shows the maximum value are quite different by the equivalence ratio.

In order to reduce particulate and NOx emission from the direct injection diesel engine, most researchers have been expecting the utilization of higher injection pressure and injection rate for improvement of diesel combustion. In the case of pump-line-nozzle system, the injection pipe line is very important with regard to the high injection pressure. Namely, the pipe line must be able to resist not only high pressure but also cavitation erosion. In this paper, the effect of high injection pressure, injection rate and sharp cutting at the end of fuel injection are discussed along with cavitation phenomena on the injection pipe line. And durability tests on the pipe line system under high injection pressure using a test rig are also described. Regarding durability tests, several measures have been taken for the injection pipe. As a result, the authors have found that the best solution for the injection pipe is a composite pipe made with SUS and steel.

This paper discusses the compact structure, innovative and unique approach of high performance spiral coil sub-cooled condenser for compact power plant/engine applications. The motivation behind this study is to reduce the engine emission by improving the coefficient of performance for air-conditioning unit. Since the air conditioning system is the most power consumption units after the power plant, so it significantly affects the fuel consumption and the hazardous gas emissions. In the air condition cycle, the condenser unit is addressed as one of the important devices, and thus, the author tried to reduce the energy consumption by improving the performance of the condenser. The most advantage points of this study is to use spiral coil sub-cooled condenser, which elaborates the effect of secondary flow generation inside the fluid and is known as the Dean’s effect.

The paper reviews the experimental development of fuel economy of engine powering the 2012 Formula SAE single seat race car of the University of Sophia. The balance of high power and low fuel consumption is biggest challenge of racing engine. It was found that improving the efficiency of engine by supercharging as a way to achieve that. In order to adapt the supercharger for the engine, the important design points are below: It was found that intake air blow-by gas at combustion chamber is increased in low engine speed. To improve that, the valve overlap angle was changed to adopt supercharged engine and improve effective compression ratio. Typically the racing engine demands maximum torque for performance but that does not imply that the air fuel ratio should be rich than theoretical. The point is the maximum torque of the engine is proportional to the amount of air intake. Therefore, supercharged engine is possible to increase the supercharging pressure for bigger torque.

For improving the thermal efficiency and the reduction of hazardous gas emission from IC engines, it is crucial to model the heat transfer phenomenon starting from the intake system and predict the intake air’s mass and temperature as precise as possible. Previously, an empirical equation was constructed using an experimental setup of an intake port model of an ICE, in order to be implemented into an engine control unit and numerical simulation software for heat transfer calculations. The empirical equation was based on the conventional Colburn analogy with the addition of Graetz and Strouhal numbers. Introduced dimensionless numbers were used to characterize the entrance region, and intermittent flow effects, respectively.

This research focuses on the improvement of torque at the middle engine speed of a motorcycle engine with resonance supercharging. The resonance supercharging intake system is realized with a simple modification to the intake collector geometry. A one-dimensional computational model is employed to simulate the pressure wave propagation and to optimize the configuration of it. The experiments confirmed the increase in the engine torque for the entire operation range and the maximum gain of 33% was achieved at 8500rpm. The resonance effect is further investigated through three-dimensional simulation, in which the intake airflow rate, static pressure distribution are analyzed.

In order to get better results in the Formula SAE of Japan, it is necessary to develop a small displacement engine with an ideal fuel consumption rate. Therefore, the authors started to improve an existing engine by combining with glow plug heated sub-chamber and lean burn. Lean burn conditions are usually adopted in gasoline engines, having the advantages of high specific heat ratio, low pump loss, and low cooling loss due to requiring a decreased combustion temperature. The combination of these elements can be expected to vastly improve thermal efficiency and fuel consumption. Unfortunately, however, when the mixture becomes lean, the ignition delay increases, and the flame propagation speed reduces. This leads to an increase in combustion fluctuation. The authors intend to solve this problem by installing a glow plug in a newly designed sub-chamber. This type of device would usually be used to heat the sub-chamber of a diesel engine to solve the cold start problem.

Measuring precise cylinder pressure traces of internal combustion engines is an important factor for estimating their performances. It is known that the actual pressure readings measured with piezoelectric pressure transducers nave various forms of error. This paper is devoted to a study of compensation methods for reducing the errors caused by time constant values and thermal shock. Numerical analysis were carried out for the both errors to derive the equations of error compensation using the actual pressure data. The results indicate that the errors are corrected quite well with the obtained equations.