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In this work, the design and testing of a silicon-nitride (Si3N4) piston-cup for a Petter AV1 laboratory diesel engine is presented. A preliminary design was first prepared and tested for thermal shock. The tests showed that non uniform displacements occurred between the ceramic plate and the piston. An improved design was then prepared, which allowed control of the characteristics of the gasket mounted between the ceramic plate and the piston. This second design was evaluated by thermal shock and exposure to cyclic pressure variation, followed by engine tests. A short description is given of the experimental set-up used for investigating the ceramic materials which are candidates for the moving parts exposed to thermal and dynamic shock in internal combustion engines. Finally two pistons with ceramic top plates were introduced in the engine with thermocouples mounted at different points of the liner and exhaust valve.

A simple, relatively short and inexpensive screening test method has been developed for evaluation of available detergent/dispersant diesel fuel additives. The screening test is based on experiments of running a laboratory diesel engine in a pre-determined regime(load cycle). The engine is a single cylinder, 4-stroke DI, naturally aspirated and air cooled. It is coupled to a generator feeding electrical heaters as the load. The test rig is controlled electronically to enable fully automatic test bench operation, including start/stop, load change, emergency shut-down, etc. The experiments were performed by running the engine on a reference base fuel and then the same fuel with different detergent additives. The nozzle of the fuel injector was checked for clogging by air flow measurements, using the ISO-4010 test rig.

The objective of this work was to demonstrate the possibility of adding a 3% methanol blend to the normal gasoline for the existing vehicle population in the climatic conditions of Israel. The fleet test was performed with the help of three public stations in which the methanol gasoline blend is sold to the general public on a voluntary basis. After ten months of operation with a sample of over 14000 vehicles the results are very encouraging and the acceptance of this blend among the drivers is very good. The extending possibility of adding a 3% methanol blend to the normal gasoline in all the public filling stations in Israel is the principal conclusion of this work.

Cross-flow heat exchangers, serving as hydride-containing reactors and aimed to absorb high temperature heat of exhaust gases, for the purpose of driving a hydrogen heat pump in the cooling mode were tested and described here. The heat transfer characteristics of the heat exchanger itself and the effects of engine exhaust gas were determined by tests in a stream of exhaust gas from a Diesel engine, with water circulating through the heat exchanger tubes. The performance of the heat exchanger as a reactor was investigated in a stream of hot gas-air mixture, which simulated engine exhaust gas. The tubes were filled with metal hydride LaNi4.7 Al0.3Hx powder and tested with and without hydrogen flowing through them.

Although many works are published about the achieved advancements in the manufacturing of the catalytic converters (CC) system for vehicle engines and their testing under laboratory conditions, there is a lack in the published research about the mileages influence on their conversion efficiency (CE). Dependence of dual-brick CCs' CE in real-world driving conditions on vehicle mileage is studied for the first time. The CC tested are dismantled from the vehicles with mileage from 0 (new one) up to 150,000 km. The studied CC are evaluated at the engine test bench containing a dynamometer coupled with a spark ignition engine suitable for this type of CC system. Measurements of CC efficiency are performed at four different engine operation regimes: two loaded regimes and two non-load regimes - low and high speed idling. It is found that the oxidation of CO and HC at all four tested regimes took place almost totally in the first CC.

At present the market of Wankel engines is limited to some special applications. This fact explains absence of commercial software products specially developed for this engine simulation and prediction of its performance. Conversely, there are available and widely used software products for simulation of reciprocating-piston engines performance. Some attempts are known in using this software for prediction of Wankel engine performance. This paper details an approach used in these attempts. Main differences between both types of engines are summarized and principles of a virtual reciprocating-piston engine compilation are developed. A method of virtual blowing was developed for assessment of discharge coefficients for intake and exhaust ports. Comparison of simulation results with the measured performance of two UAV Wankel engines showed sufficient accuracy of the suggested approach.

Results obtained from tests on an air cooled Rotary Trochoidal Engine fuelled with a gasoline-alcohol mixture, without modification of the carburetor, are presented in this paper. The tests were performed with one and two spark plugs. Amongst the obtained results, lower thermal load, better economy and improvement in cycling uniformity when running with two spark plugs were observed. The observed reduction in the rotor housing wall temperature and in the oil sump temperature presents particular advantages for an air cooled engine.