A turbocharger is certainly one of the fundamental devices being employed to enhance output power of petrol and/or diesel and is of paramount importance for use in heavy duty diesel engines.This work aims to increase the power of a six-cylinder turbocharged, four stroke, direct injection heavy duty diesel engine via replacing its fitted turbocharger with a properly selected and matched one. The matching criteria and the effect of intercooler presence are studied. A performance prediction model for turbocharged engine is created to investigate the engine-turbocharger matching. To address this, a program code has been upgraded and modified to select the suitable engine turbocharger using FORTRAN PowerStation 5.0 language. The study includes also an experimental part; where three types of turbochargers, (namely HX80, HB3 and HX40) are tested. The P-Ф diagram, the engine performance parameters together with the exhaust and soot emissions are measured and compared for the cases of original and best turbocharger (HX80). The developed computer algorithm appears to provide results that are in good agreement, within acurcey of + 5%, with the measured data; a fact that encourages designers to trustly use it in their selection and matching of a turbocharger to diesel engines.

Waste tires is one of the solid residuals that can have serious impacts environmentally. Therefore, controlling this waste through conversion into valueadded products such as bio-fuels is highly recommended. Consequently, this work reports catalytic-hydrocracking of waste tire pyrolytic oil (WTPO) to fuels over Ni-W supported on zeolite X and A. The zeolites were hydrothermally synthesized from another type of waste, namely blast furnace slag (BFS). The prepared samples were characterized by X-ray diffraction (XRD) analysis. The successive synthesis of zeolites A and X could be detected through observing cubic and octahedral particles via scanning electron microscopy (SEM). The two prepared catalysts presented mesoporous natures with reasonable specific surface area, as acquired from nitrogen adsorption-desorption analysis. The catalysts activity toward upgrading of WTPO was investigated under different operating conditions. Particularly, both catalysts have exhibited high activity through producing reasonable yields of gasoline (35% and 40%) and high yields of diesel (45% and 30%) by Ni-W loaded zeolite A and X, respectively. Additionally, zeolite X supported catalyst showed a higher selectivity toward catalytic HDS of WTPO than the zeolite A. The former optimum findings were collected at the following operating conditions: 80 bar, 450 C and LHSV of 1.2 h À1 .

The present paper experimentally examines the influence of the progressive variations of the central air jet velocity in a concentric circular-elliptical inverse diffusion flame (IDF) on the visual and thermal structure and stability of the developed flames. All experiments are conducted at a fixed fuel flow rate (liquefied petroleum gas) throughput that emerges from the annular elliptic passage having an aspect ratio of 2:1. The visual images are aided via a digital camera and shadowgraphs, while the thermal structure (axial and radial temperature profiles) is acquired using a bare fine wire (125 µm) thermocouple; rendering radiation loss insignificant. The visual images and shadowgraphs clearly indicate the existence of four regimes: (i) an annular partially premixed region at the burner rim, (ii) an inner central premixed blue flame, (iii) an outer luminous yellowish post combustion zone and (iv) the flame tip buoyant zone. The progressive increases of the central average air velocity ( ̅ = 7.4 m/s up to 31.3 m/s) result in shortening the visible flame length and narrowing the flame width. These are coupled with changing the flame appearance from a yellowish diffusion flame with a sooty core regime to an intense central premixed flame surrounded by a soot ring to blue flames exhibiting intense central radiation regime associated with soot oxidation. At extremely high air velocity > 21 m/s, locals flame extinction and re-ignition occurs at the boundaries of the ellipse minor axis and further increase of ̅ causes complete extinction of the main flame. These findings are very much supported by the mean gas temperature measurements that indicate steep temperature rise associated with the formation of a central premixed combustion within the flame core which is followed by the diffusion mode of combustion. A plateau of the axial temperature profiles is observed in the transition zone between the two regions whereby the rise in temperature due to soot oxidation is balanced by the radiation loss.

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Increase of the capacity of heavy duty diesel engines is of great interest in the way of power enhancement in many engine applications. Turbocharger is one of the most important ways used to increase the engine specific power. The present study aimed to develop an analytical model to simulate the performance and combustion characteristics of a direct injection diesel engine. This model depends on the basic conservation equations of continuity, momentum and energy as well as equation of state, these equations are solved together numerically by using two steps Lax-Wendroff scheme. To address this, a comprehensive computer “FORTRAN” code was developed and applied to study the performance and combustion characteristics of a six-cylinder, four stroke, direct injection, heavy duty diesel engine as a base engine and when its power upgraded by 15% using a turbocharger. This code is open source, preprocessor is user-friendly and very easy in work and will used at any time. The computed results are compared with the results obtained by applying the engine simulation DIESEL-RK software. But the DIESEL-RK solver may be run under the control of an external code. In that case the interface of the program includes input & output text files. Templates of these files are generated automatically. The developed model provides reasonable estimates and the experimental validation of the model show that an appropriate agreement between mathematical model, DIESEL-RK software, and the real measurements, in addition the capability of the model to predict satisfactorily the performance, and combustion characteristics of the direct injection diesel engine. Simulation study was also performed to compare the turbocharged engine with the naturally aspirated direct injection diesel engine. This study examined the engines for operating parameters like brake power and brake specific fuel consumption over the entire speed range and revealed that turbocharging offers higher brake power and lower brake specific fuel consumption values for most of the operating range. The results indicated that turbocharging offers marginally higher brake thermal efficiency and enhancing the engine performance.