The present work considers the turbulent air flow inside an annular high speed rotor-stator cavity opened to the atmosphere at the periphery. The interdisk-spacing is sufficiently large so that the boundary layers developed on each disk are separated and the flow belongs to the regime IV of Daily and Nece (1960). In such a system, the solid body rotation of the core predicted by Batchelor in ca...

With a view to understanding the air-fuel mixing behavior and the effects of the mixture quality on the emissions formation and engine performance, a new quantitative factor of the in-cylinder air-fuel homogeneity named Homogeneity Factor (HF) has been developed. Its characteristics under various injection conditions and air swirl motions within the cylinder have been investigated with CFD simu...

Title of Document: SPRAY FLAME AND EXHAUST JET CHARACTERISTICS OF A PRESSURIZED SWIRL COMBUSTOR Martin Brendan Linck, Doctor of Philosophy, 2006 Directed By: Professor Ashwani K. Gupta Department of Mechanical Engineering This work describes an investigation of swirl-stabilized flames, created in a combustor featuring co-annular swirling airflows, under unenclosed, enclosed, and submerged condi...

This study numerically analyses the effects of chamber modifications to investigate improvement in-cylinder combustion characteristics diesel engine using a computational fluid dynamics (CFD) approach. Five different modified chambers, namely, double swirl (DSCC), bathtub (BTCC), toroidal re-entrant (DTRCC), shallow depth (SCC), and stepped bowl (SBCC) were developed compared with reference fla...

The characteristics of the axial flow within the core of a concentrated line vortex are investigated using molecular tagging velocimetry (MTV). A well-defined array of isolated vortices of alternating sign is generated in the wake of a NACA-0012 airfoil pitching sinusoidally at small amplitude and high reduced frequencies. The circulation and peak vorticity of the vortices are varied by the cho...

We show in this study that the combination of a swirl flow reactor and an antimicrobial agent (in this case copper alginate beads) is a promising technique for the remediation of contaminated water in waste streams recalcitrant to UV-C treatment. This is demonstrated by comparing the viability of both common and UV-C resistant organisms in operating conditions where UV-C proves ineffective - no...

The effect of swirling on the flow characteristics of tubes with sudden expansion is experimentally examined by 3D particle image velocimetry(PIV) technique to determine velocity profiles. The swirling flow of water in sudden 1:2 axisymmetric expansion has been previously studied within a horizontal round tube. A tangential slot is used as a swirl generator for swirling flow, whereas a honey co...

In this paper we study turbulent premixed methane flames with swirl using three-dimensional numerical simulation. The simulations are performed using an adaptive time-dependent low Mach number combustion algorithm based on a second-order projection formulation that conserves both species mass and total enthalpy. The species and enthalpy equations are treated using an operator-split approach tha...

A premixed turbulent combustion Direct Numerical Simulation (DNS) database of a swirl burner is analyzed from three angles: estimation of the three-dimensional flame surface from two-dimensional fields; modeling of subgrid source and flux terms entering the balance equation for the reaction progress variable in Large Eddy Simulation (LES); and modeling of the subgrid-scale scalar variance in LE...

Abstract Measurements of sound due to swirl–nozzle interaction are presented. In the experiment a swirl structure was generated by means unsteady tangential injection into steady swirl-free flow upstream from choked convergent–divergent nozzle. Ingestion nozzle caused mass-flow rate change, which resulted in downstream-measured acoustic response. The downstream pressure found remain negative as...