Laminar hydrocarbon flames, which have adiabatic flame speeds on the order of a meter per second, are conventionally described by a leading convective-diffusive zone followed by an energyreleasing reactive-diffusive region. On the other hand, combustion induced by a strong shock wave is typically modeled as a convective-reactive balance with negligible diffusion, which may be called a convectiv...

A droplet vaporization model has been developed for use in high pressure spray modeling. The model is a modification of the common Spalding vaporization model that accounts for the effects of high pressure on phase equilibrium, transport properties, and surface tension. The new model allows for a nonuniform temperature within the liquid by using a simple 2-zone model for the droplet. The effect...

SUMMARY This is the second part of the numerical investigation on a low emissions staged turbine combustor (STC) using a modified version of the KIVA-II code. The main focus of this study is the numerical analysis of the reacting fluid flow and heat transfer inside the quick-quench/lean-combustion (QQ/LC) zones. In the QQ zone, cool dilution air was injected into the hot mixture through eight 4...

E. L. Resler, Jr. Sibley School ol Mechanica l and Aerospace Engineering, Cornell University, Ithaca, NY 14853 The wa~•e roror is a promising means of pressure-gain for gas turbine engines. This paper examines novel wave rotor topping cycles that incorporate low-NO,, combustion straregies. This approach combines two-s rage ''rich-quench-lean'· ( RQL) combustion with inrermediate expansion in th...

To avoid the complexities associated with the droplet/vapor transport and nonuniform evaporation processes, a fundamental investigation of liquid fuel combustion in idealized configurations is very useful. An experimental–computational investigation of prevaporized n-heptane nonpremixed and partially premixed flames established in a counterflow burner is described. There is a general agreement ...

The present work addresses unsteady flame dynamics in a lean-premixed swirl-stabilized combustor, with attention focused on the transition of flame structure from a stable to an unstable state. It was found that the inlet temperature and equivalence ratio are the two most important variables determining the stability characteristics of the combustor. A slight increase in the inlet mixture tempe...

Homogenous Charge Compression Ignition (HCCI) engines hold promise of high fuel efficiency and low emission levels for future green vehicles. But in contrast to gasoline and diesel engines, HCCI engines suffer from lack of having direct means to initiate combustion. A combustion timing controller with robust tracking performance is the key requirement to leverage HCCI application in production ...