A study on an application of a hybrid break-up model for dimethyl ether atomization in a common-rail injection system

Abstract

In this study, experimental and numerical investigations were performed to analyse the spray characteristics of dimethyl ether (DME) fuel in a common-rail fuel injection system. In order to analyse the DME fuel spray, overall spray characteristics such as the spray tip penetration, the spray evolution process, and the droplet size distribution were investigated by an application of the hybrid break-up model combined with primary and secondary break-up phenomena. The spray development process and spray tip penetration were measured experimentally from injected DME spray images obtained using a visualization system, while the microscopic characteristics were experimentally measured by a phase Doppler particle analyser system. Calculations based on hybrid break-up models were validated against the experimental results, and the associated break-up constants were optimized after the validation. Based on the optimized break-up constant, the calculated results under various experimental conditions were compared with measured results such as the spray development, the spray tip penetration, the Sauter mean diameter (SMD), and the SMD distribution.

Ammonia Combustion in a Spark-Ignition Engine Supported with Dimethyl Ether

“…One of the main disadvantages of ammonia as a fuel is its lower reactivity than conventional coal-based fuel, which complicates the combustion process and may negatively affect the emission of toxic and harmful exhaust gas components. Its relatively low calorific value (LHV = 18.8 MJ/kg), high heat of vaporization (HoE = 1370 kJ/kg), low laminar combustion speed (LFS = 0.015 m/s), high auto-ignition temperature (651 • C), and narrow flammability range (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28) hinder the use of ammonia in piston engines [21]. These properties create problems in effective combustion in both compression ignition and spark-ignition engines.…”

Numerical study of EGR effects on the combustion process parameters in HCCI engines

“…Dzięki regulacji temperatury początkowej przez mieszanie stałej ilości paliwa ze zmieniającą się ilością EGR, można regulować wartością CA50. Dla tego samego CA50, wzrost stopnia EGR powoduje przesunięcie czasu wystąpienia LTHR, a czas trwania termicznego przy-Among various alternative fuels, dimethylether (DME) has become a primary candidate to replace diesel fuel because it is estimated that the exhaust emissions from vehicles using DME are significantly lower than the exhaust emissions from vehicles using diesel fuel [9]. From the viewpoint of combustion characteristics, DME fuel can be operated in a diesel cycle and obtains a similar thermal efficiency to diesel fuel owing to its good self-ignitability and high cetane number.…”

“…Przedstawiono w niej wpływ stopnia EGR na podstawowe parametry procesu spalania, tj. chwilę początku zapłonu (SOI), czas trwania spalania (BD), ciśnienie indykowane (p i ) i emisję tlenku azotu (NO), jednocylindrowego silnika z samoczynnym zapłonem mieszanki jednorodnej (HCCI) zasilanym paliwem DME (eter dimetylowy).Wśród różnych paliw alternatywnych eter dimetylowy (DME) ma stać się podstawowym kandydatem do zastąpienia oleju napędowego, ponieważ szacuje się, że emisja toksycznych składników dla pojazdów zasilanych DME jest znacznie niższa od emisji pojazdów zasilanych olejem napędowym [9]. Z punktu widzenia charakterystyk spalania paliwo DME może pracować w cyklu Diesla i umożliwia uzyskanie podobnych wartości sprawności cieplnej do oleju napędowego, ze względu na jego dobre właściwości samozapłonu i wysoką liczbę cetanową.…”