Instability of a swirling annular liquid sheet in swirling inner and outer air streams has been investigated by a temporal linear stability analysis. The effects of the swirling and axial motion of the liquid and the air streams, as well as the effects of relative inner and outer air swirl orientation with respect to the liquid swirl direction on the instability have been investigated. Results ...

The SWarm Intelligence-based Reinforcement Learning (SWIRL) method is proposed in this paper to efficiently generate Artificial Neural Network (ANN) based solutions to various problems. Basically, two swarm intelligence based algorithms are combined together in SWIRL to train the ANN models. Ant Colony Optimization (ACO) is applied to optimize ANN topology, while Particle Swarm Optimization (PS...

Increasing interest has been given to swirl brakes as a means of reducing destabilizing rotordynamic.forces due to leakage flows in new high speed rocket turbopumps. Although swirl brakes have been used successfully in practice {such as with the Space Shuttle HPOTP), no experimental tests until now have been pegormed to demonstrate their beneficial effect over a range of leakage flow rates. The...

The effect of inlet swirl on the flow development and combustion dynamics in a lean-premixed swirl-stabilized combustor has been numerically investigated using a large-eddy-simulation (LES) technique along with a level-set flamelet library approach. Results indicate that when the inlet swirl number exceeds a critical value, a vortex-breakdown-induced central toroidal recirculation zone is estab...

ROSS, an object-oriented language that has evolved over the last two years as part of the knowledge-based simulation research at Rand [1,3,6,7,8,91. We describe a program called SWIRL designed for simulating military air battles between offensive and defensive forces. SWIRL is written in an object-oriented language (ROSS) where the knowledge base consists of a set of objects and their In the fo...

An investigation into in-cylinder swirl and tumble flow characteristics with reduced maximum valve lifts (MVL) is presented. The experimental work was conducted in the modified four-valve optical spark-ignition (SI) test engine with three different MVL. Particle image velocimetry (PIV) was employed for measuring in-cylinder air motion and measurement results were analyzed for examining flow fie...

ROSS |7] is an object-oriented language developed for building knowledge-based simulations [4l. SWIRL |5, 6] is a program written in ROSS that embeds knowledge about defensive and offensive air battle strategies. Given an initial configuration of military forces, SWIRL simulates the resulting air battle. We have implemented ROSS and SWIRL in several different Lisp environments. We report upon t...

Flame stabilization by swirl is a common feature of many combustors. While most of the swirl combustors are enclosed, there have been relatively few studies of open swirl-stabilized flames. In the current study, an open swirl-stabilized turbulent premixed flame is studied numerically. The purpose of this work is to obtain a better understanding of the flame properties by simulating the flow fie...

Flow watermarks are active traffic analysis techniques that help establish a causal connection between two network flows by content-independent manipulations, e.g., altering packet timings. Watermarks provide a much more scalable approach for flow correlation than passive traffic analysis. Previous designs of scalable watermarks, however, were subject to multi-flow attacks. They also introduced...

This paper examines the manner in which heat release resulting from premixed combustion alters the nature of near-critical, axisymmetric, swirling flow in a straight circular pipe. Attention is confined to dilute premixtures so that exothermicity is weak and a small-disturbance approach applicable. The weak exothermicity is found to have a considerably larger effect on the flow. In the absence ...