Findings on droplet breakup behavior of the preheated microalgae oil jet for efficiency improvement in diesel engines

Author(s):  
Sergejus Lebedevas ◽  
Oleh Klyus ◽  
Laurencas Raslavičius ◽  
Pawel Krause ◽  
Paulius Rapalis
1999 ◽  
Vol 52 (4) ◽  
pp. 119-138 ◽  
Author(s):  
J. Senda ◽  
H. G. Fujimoto

This article summarizes model analysis of the dispersion process of a Diesel spray on the wall surface in order to simulate the spray-wall interaction process in Diesel engines. The mixture formation process near the wall of the piston cavity affects the combustion process and the hydrocarbon or soot formation process through the quenching of the mixture and flame at the wall surface. In particular, mixture burning occurs mainly near the cavity wall through the whole combustion period in the case of high pressure fuel injection. In this article, representative modeling approaches on spray-wall interaction process including the film flow formation are summarized briefly. Then, our models of spray impingement for low/high-temperature models including the process of fuel film formation, film breakup, wall-drop/film heat transfer, and droplet breakup owing to the solid-liquid interface boiling are introduced with the comparison of experimental results. This review article includes 83 references.


Author(s):  
Sandeep Kumar Goyal ◽  
Avinash Kumar Agarwal

The continuous increase in power density has led to higher thermal loading of pistons of heavy duty diesel engines. Material constraints restrict the maximum operating temperature of a piston. High piston temperature rise may lead to engine seizure because of piston warping. To avoid this, pistons are usually cooled by oil jet impingement from the underside of the piston in heavy duty diesel engines. Impingement heat transfer has been used extensively because of the high rates of cooling it provides. The associated high heat transfer rate is due to the oil jet that impacts hot impingement surface at high speed. However, if the temperature at the underside of the piston, where the oil jet strikes the piston, is above the boiling point of the oil, it may contribute to the mist generation. This mist significantly contributes to non tail-pipe emission (non-point source) in the form of unburnt hydrocarbons (UBHC’s). This paper presents and discusses the results of a numerical and experimental investigation of the heat transfer between a constant heat flux flat plate and an impinging oil jet. Piston boundary conditions are applied to the flat plate. Using the numerical modeling, heat transfer coefficient (h) at the underside of the piston is calculated. This predicted value of heat transfer coefficient significantly helps in selecting right oil grade, oil jet velocity, nozzle diameter and distance of the nozzle from the underside of the piston. It also helps to predict whether the selected grade of oil will contribute to mist generation. Using numerical simulation (finite element method) temperature profiles are evaluated by varying heat flux. Infrared camera is used to investigate and validate the temperature profile of the flat plate. High speed camera is used to capture the mist generation and oil jet breakup due to impinging jet.


Author(s):  
Serhii Kovalov

The expediency of using vehicles of liquefied petroleum gas as a motor fuel, as com-pared with traditional liquid motor fuels, in particular with diesel fuel, is shown. The advantages of converting diesel engines into gas ICEs with forced ignition with respect to conversion into gas diesel engines are substantiated. The analysis of methods for reducing the compression ratio in diesel engines when converting them into gas ICEs with forced ignition has been carried out. It is shown that for converting diesel engines into gas ICEs with forced ignition, it is advisable to use the Otto thermo-dynamic cycle with a decrease in the geometric degree of compression. The choice is grounded and an open combustion chamber in the form of an inverted axisymmetric “truncated cone” is developed. The proposed shape of the combustion chamber of a gas internal combustion engine for operation in the LPG reduces the geometric compression ratio of D-120 and D-144 diesel engines with an unseparated spherical combustion chamber, which reduces the geometric compression ratio from ε = 16,5 to ε = 9,4. The developed form of the combustion chamber allows the new diesel pistons or diesel pistons which are in operation to be in operation to be refined, instead of making special new gas pistons and to reduce the geometric compression ratio of diesel engines only by increasing the combustion chamber volume in the piston. This method of reducing the geometric degree of compression using conventional lathes is the most technologically advanced and cheap, as well as the least time consuming. Keywords: self-propelled chassis SSh-2540, wheeled tractors, diesel engines D-120 and D-144, gas engine with forced ignition, liquefied petroleum gas (LPG), compression ratio of the internal com-bustion engine, vehicles operating in the LPG.


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