Tidal stream turbines (TSTs) produce a rotating downstream wake. This paper describes the characteristics of the swirl flow in the wake of a TST with a view of comparing these against classical swirl theory and investigating whether swirl is an important factor in wake recovery prediction. Using computational fluid dynamics the paper describes the characteristics of velocities, pressure drop, v...

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...

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 ...

a newly developed heavy duty diesel engine in dual fuel mode of operation has been studied in detail. the main fuel would be natural gas and diesel oil as pilot injection. the importance and effects of mixture preparation and formation through ports, valves and in cylinder flow field with different swirl ratio and tumble on diesel combustion phenomena is an accepted feature which has been studi...

A 1arge-scale tumble rather than swirl would exist in cylinders in the case of two valves’ opening in a fourvalve engine. A strong swirl is generated when one valve is closed, yet the flow capacity is less than that of two valves being opened. In order to change it, different lifts of valves (DLV) present are achieved. In the case of using different lifts of two intake valves, both tumble and s...

A newly developed heavy duty diesel engine in dual fuel mode of operation has been studied in detail. The main fuel would be natural gas and diesel oil as pilot injection. The importance and effects of mixture preparation and formation through ports, valves and in cylinder flow field with different swirl ratio and tumble on diesel combustion phenomena is an accepted feature which has been studi...

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...

The influence of swirl on the shape of the Burke-Schumann reaction sheet in a straight cylindrical pipe is investigated by asymptotic and numerical means. Attention is confined to swirl levels that are near the critical value at which vortex breakdown occurs. A high Reynolds number, laminar, isothermal, low Mach number reacting flow is considered. An asymptotic analysis is developed to study th...

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...

One-dimensional stability analysis of a hydraulic system composed of a penstock, a runner, and a draft tube was carried out to determine the cause of the full load draft tube surge. It is assumed that the cavity volume at the runner exit is a function of the pressure at the vortex core evaluated from the instantaneous local pressure at the runner exit and an additional pressure decrease due to ...