Mechanical Engineering Commons^™

A Five-Zone Model For Direct Injection Diesel Combustion, Rich Asay

Theses and Dissertations

Recent imaging studies have provided a new conceptual model of the internal structure of direct injection diesel fuel jets as well as empirical correlations predicting jet development and structure. This information was used to create a diesel cycle simulation model using C language including compression, fuel injection and combustion, and expansion processes. Empirical relationships were used to create a new mixing-limited zero-dimensional model of the diesel combustion process. During fuel injection five zones were created to model the reacting fuel jet: 1) liquid phase fuel 2) vapor phase fuel 3) rich premixed products 4) diffusion flame sheath 5) surrounding bulk …

Two Dimensional Numerical Simulation Of Highly-Strained Hydrogen-Air Opposed Jet Laminar Diffusion Flames, Kyu C. Hwang

Mechanical & Aerospace Engineering Theses & Dissertations

In this study, a detailed 2-D numerical technique is utilized to investigate the structure, and flame extinction and restoration characteristics of laminar hydrogen-air opposed jet diffusion flames, using both plug (uniform) and parabolic inflow boundary conditions for 3 millimeter jet tubes, spaced 6 millimeters apart and imbedded in low velocity coflows.

First, by using the most recent of two chemical kinetic models, excellent agreement was obtained between calculated distributions of temperature and major species, and published UV laser Raman scattering measurements, for 50% and 100% hydrogen-air flames over a range of input strain rates. Agreement with measured OH profiles was …

Numerical Studies On Supersonic Mixing And Combustion Phenomena, Tarek M. Abdel-Salam

Mechanical & Aerospace Engineering Theses & Dissertations

A numerical study is conducted to investigate the mixing, combustion, and flow characteristics of different scramjet-combustor configurations. Three-dimensional models for the combustors have been used. Numerical results are obtained using a finite volume computational fluid dynamics (CFD) code with unstructured grids with sizes between 200,000 and 400,000 cells.

In the first part of the current study, the effects of the side angle of the fuel injectors in both mixing and combustion processes are investigated. Raised (compression) and relieved (expansion) wall-mounted ramps are used with side angles of 0 (unswept), 5, and 10 degrees. Results are obtained for nonreacting flows as …