a computational optimization was performed for a direct-injection diesel engine using three-dimensional modeling. fully transient cfd analyses of different valve profile strategies for the intake and compression strokes were performed to evaluate the effects on both engine performance and in-cylinder flow-field evolution. the turbulence model was used along with the second order linear upwind s...

In this study the influence of the exit tube geometry on the overall flow properties of cyclones is investigated using detached eddy simulation. The results for different exit pipe shapes and lengths reveal that under certain conditions the outlet has an upstream effect on the flow behaviour within the cyclone. This can in turn result in poor build-up of swirl in the crucial region of the cyclo...

for a long time, many efforts have been taken on improving gas turbine performance to increase the propulsive force and keep the chamber walls cool. in this regard, implementation of cyclonic and vortex engines have been proposed. according to increasing in the engine efficiency and keeping the chamber walls cool, the bidirectional vortex flow which is exited in the vortex engine, makes researc...

A computational optimization was performed for a direct-injection diesel engine using three-dimensional modeling. Fully transient CFD analyses of different valve profile strategies for the intake and compression strokes were performed to evaluate the effects on both engine performance and in-cylinder flow-field evolution. The turbulence model was used along with the second order linear upwin...

Generally, micro gas turbines are in the range of 15 to 300 kW. However, recent applications unmanned aerial vehicles (UAVs) and polygeneration require a small turbine. So, here swirl combustor designed for turbine engine capacity less than 1 kW is analyzed under nonreacting flow conditions. Simulations have been carried out study field inside can combustor. Flow characteristics, like velocity,...

Abstract A comprehensive numerical model is proposed to study the influence of an axial magnetic field (AMF) on solidification behavior a Titanium-based (Ti–6Al–4V) vacuum arc remelting (VAR) ingot. Both static and time-varying AMF are examined. The 2D axisymmetric swirl includes calculating electromagnetic thermal fields in entire system composed electrode, plasma, ingot, mold. combination vec...

Existence of an exact solution of the Navier-Stokes equations representing swirling flow consisting of two fluid layers is proven. It is assumed that the fluid in the bottom layer is injected into the swirl from a rotating disk. This describes the case when a disk melts in an ambient fluid and the melted fluid is removed by rotation of the disk.

The importance of renewable energy sources for the electrical power supply has grown rapidly in the past decades. Their often unpredictable nature however poses a threat to the stability of the existing electric grid. Hydroelectric powerplants play an important role in regulating the integration of renewable energy sources into the network by supplying on-demand load balancing as well as primar...

In this paper, the non-reacting flow in a swirl burner is studied using large eddy simulation. The configuration consists of two unconfined coannular jets at a Reynolds number of 81,500. The flow is characterized by a Swirl number of 0.93. Two cases are studied in the paper differing with respect to the axial location of the inner pilot jet. It was observed in a companion experiment (Bender and...

One of the drawbacks of hybrid rocket motors is the limited regression rate of the fuel grain, which impacts on the scalablility of the type. A number of methods of increasing this have been proposed and successfully tested, in particular the use of swirling oxidiser flow to create turbulence and increase the local oxidiser mass flux. However, many of these have limitations in practical motors ...