A series of studies has been conducted investigating the behavior of di-methyl ether (DME) fuel jets injected into quiescent combustion chambers. These studies have shown that it is possible to make a good estimate of the penetration of the jet based on existing correlations for diesel fuel, by using appropriate fuel properties. The results of the spray studies have been incorporated into a first generation model for DME combustion. The model is entirely based on physical mixing, where chemical processes have been assumed to be very fast in relation to mixing. The assumption was made on the basis of the very high Cetane number for DME. A spray model similar to that proposed by Hiroyasu et al. [11] has been used, with the assumption that rapid combustion occurs when the local mixture attains a stoichiometric air fuel ratio. The spray structure is based on steady-state spray theory, where the shape of the spray has been modified to match the measured spray penetration rates. The spray theory and experimentally determined penetrations implicitly determine the rate of air entrainment into the spray. The results show that the combustion rates calculated during the mixing controlled portion of combustion agree well with experimental measurements from a previous study, without additional adjustment.

Issue Section:
Internal Combustion Engines
Keywords:
internal combustion engines, fuel, organic compounds, sprays, jets, modelling, automobiles, performance evaluation
Topics:
Combustion, Fuels, Sprays, Ethers (Class of compounds), Heat, Diesel engines
1.
Sorenson, S. C., and Mikkelsen, S.-E., 1995, “Performance and Emissions of a 0.273 Liter Direct Injection Diesel Engine Fueled with Neat Dimethyl Ether,” SAE Paper 950964.
2.
Hansen, J. B., Voss, B., Joensen, F., and Sigurdardo´ttir, D., “Large Scale Manufacture of Dimethyl Ether—a New Alternative Diesel Fuel from Natural Gas,” SAE Paper 950063.
3.
Fleisch, T., McCarthy, C., Basu, A., Udovich, C., Charbonneau, P., Slodowske, W., Mikkelsen, S.-E., and McCandless, J., 1995, “A New Clean Diesel Technology: Demonstration of ULEV Emissions on a Navistar Diesel Engine Fueled with Dimethyl Ether,” SAE Paper 950061.
4.
Kapus, P., and Ofner, H., 1995, “Development of Fuel Injection Equipment and Combustion System for DI Diesels Operated on Dimethyl Ether,” SAE Paper 950062.
5.
Kapus, P., and Cartellieri, W., 1995, “ULEV Potential of a DI/TCI Diesel Passenger Car Engine Operated on Dimethyl Ether,” SAE Paper 952754.
6.
Mikkelsen, S.-E., Sorenson, S. C., and Hansen, J. B., 1996, Dimethyl Ether as an Alternate Fuel for Diesel Engines, Application of Powertrain and Fuel Technologies to Meet Emissions Standards, Institution of Mechanical Engineers, London, pp. 289–298.
7.
Christensen, R., 1996, “DME as a Fuel in a DI Diesel Engine,” MS thesis, Report ET-EP 96-24, Dept. of Energy Engineering, Technical University of Denmark. (In Danish).
8.
Katijani, S., Chen, Z. L., Kono, M., and Rhee, K. T., 1997, “Engine Performance and Exhaust Characteristics of a Direct-Injection Diesel Engine Operated with DME,” SAE Paper 972973.
9.
Glensvig, M., Sorenson, S. C., and Abata, D. L., 1996, “High Pressure Injection of DME,” in Alternative Fuels, Vol. 27-3, ASME Internal Combustion Engine Division, p. 57.
10.
Sorenson, S. C., Glensvig, M., Abata, D. L., 1998, “Dimethyl Ether in Diesel Fuel Injection Systems,” SAE Paper 981159.
11.
Hiroyasu, H., Kadota, T., and Arai, M., 1983, “Development and use of a Spray Combustion Modeling to Predict Diesel Engine Efficiency and Pollutant Emissions, Parts 1 & 2. Bulletin of the ASME, Vol. 26, papers 214–12 and 214–15.
12.
Edgar, B. L., Dibble, R. W., and Naegli, D. W., 1997, “Autoignition of Dimethyl Ether and Dimethoxy Methane sprays at High Pressures,” SAE Paper 971677.
13.
Christensen, R., Sorenson, S. C., Jensen, M. G., and Hansen, K. F., 1997, “Engine Operation on Dimethyl Ether in a Naturally Aspirated, DI Diesel Engine,” SAE Paper 971665.
14.
Turns, S. R., 1996, “Introduction to Combustion, Concepts and Applications,” McGraw-Hill, NY.
15.
Schlicting, H., 1960, Boundary Layer Theory, McGraw-Hill, NY.
16.
Assanis, D., and Heywood, J. B., Jr., 1986, “Development and use of a Computer Simulation of the Turbocompounded Diesel System for Engine Performance and Component Heat Transfer Studies, SAE paper 860329.
17.
Woschni, G., 1967, “A Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine,” SAE Paper 670931.
18.
Olikara, C., and G. L. Borman, 1974, “A Computer Program for Calculating Properties of Equilibrium Combustion Products with Some Applications of IC Engines,” SAE paper 740468.
Copyright © 2001
 by ASME
You do not currently have access to this content.