Fuel temperature influence on diesel sprays in inert and reacting conditions

Abstract

Elsevier Payri Marín, R.; García Oliver, JM.; Bardi, M.; Manin, J. (2012). Fuel temperature influence on diesel sprays in inert and reacting conditions. Applied Thermal Engineering. 35:185-195. Abstract The detailed knowledge of the evaporation-combustion process of the Diesel spray is a key factor for the development of robust injection strategies able to reduce the pollutant emissions and keep or increase the combustion efficiency. In this work several typical measurement applied to the diesel spray diagnostic (liquid length, lift-off length and ignition delay) have been employed in a novel continuous flow test chamber that allows an accurate control on a wide range of thermodynamic test conditions (up to 1000 K and 15 MPa). A step forward in the control of the test boundary conditions has been done employing a special system to study the fuel temperature effect on the evaporation and combustion of the spray. The temperature of the injector body has been controlled with a thermostatic system and the relationship between injector body and fuel temperature has been observed experimentally. Imaging diagnostics have been employed to visualize the liquid phase penetration in evaporative/inert conditions and, lift off length and ignition delay in reactive condition. The results underline a clear influence of the injector body temperature on both conditions, evaporative and, in a lesser degree, reactive; finally the physical models found in the literature have been compared with the results obtained experimentally.

Experimental characterization of diesel ignition and lift-off length using a single-hole ECN injector

“…Dec and Coy [21]  When measuring the very weak emissions of CH* the sensitivity of the setup is fundamental, and even an intensified camera may not be able to catch the very beginning of cool flames [16]. Moreover, in the case CH* emissions are detected it is not straight forward to know that the setup is catching the emissions from the beginning.…”

“…The boundary conditions have been deeply characterized in [14] and a complete description of the facility is given in [15], [16].…”

“…The injection system employed consists of commercial available components: a high pressure volumetric Bosch CP3 pump driven by an electric motor; a common rail with pressure regulator controlled by a PID system; and a special injector holder which is used to keep constant the injector tip temperature [16] [6]). The injector features a single-hole axial nozzle enabling the advantage to focus on the fundamental behavior of the spray eliminating both the effects and the uncertainties related to the temperature boundary layer close to the walls and the sprayspray interaction.…”

Engine combustion network: Influence of the gas properties on the spray penetration and spreading angle

“…Attending to the limit test conditions (ambient pressure up to 15 MPa and ambient temperature up to 1000 K), the large test chamber (up to 110 mm of free field) and the wide optical access (three windows with a 128 mm diameter), this facility constitutes one of the most advanced tools to study the diesel spray. This facility was fully described in [14].…”

An experimental analysis on the evolution of the transient tip penetration in reacting Diesel sprays

“…The usual approach for the research community to undertake spray mixing studies has been by decoupling it from the combustion process by using singular test rigs that reproduce engine thermodynamic conditions in an oxygen-free atmosphere [3][4][5][6]. Such non-reacting studies have been focused on the detailed description of quantitative spray parameters, such as vapor spray tip penetration, liquid length, or local equivalence ratio.…”