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Showing 1 to 20 of 21 for “"swirling flows"”.
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Modelling of turbulent swirling flows
… non-reacting and reacting anistropic turbulent, swirling flows using popular turbulence models with a robust numrical procedure. The performance of these turbulence models is assessed and compared against experimental data for anisotropic, turbulent swirling flow in a cylindrical pipe and …
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CFD Study of Taylor-Like Vortices in Swirling Flows
<p>Swirling flows are complex fluid motions that appear in various natural phenomena and man-made devices. Numerous engineering applications such as turbomachinery, jet engine combustion chambers, mixing tanks and industrial burners involve swirling flows. This wide range of applications is due to …
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Experimental aero-acoustic assessment of swirling flows for drag applications
… presented in this thesis regards the use of swirling exhaust flows capable of generating pressure drag quietly by establishing a steady streamwise vortex. The simple concept of a so called swirl tube, a ducted set of stationary turning vanes, was implemented to experimentally assess the …
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Simulation of vorticity dynamics in swirling flows, mixing and vortex breakdown
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1996.
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Experimental Investigation of Large Scale Aerodynamics on Soot Emissions in Swirling Flows
… (RQL) technology that employs turbulent swirling flames with downstream dilution air. These turbulent flames exhibit spatial and temporal fluctuations not present in laminar flames. This adds a level of complexity to turbulent soot studies that is yet to be fully understood. In this …
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Investigation of Dynamics in Turbulent Swirling Flows Aided by Linear Stability Analysis
Turbulent swirling flows are important in many applications including gas turbines, furnaces and cyclone dust separators among others. Although the mean flow fields have been relatively well studied, a complete understanding of the flow field including its dynamics has not been achieved. The work …
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Concentration And Velocity Fields Throughout The Flow Field Of Swirling Flows In Gas Turbine Mixers
… and incorporated swirl vanes to produce a swirling flow to promote fuel/air mixing. The fuel was injected into the bulk flow from the pressure side of the swirl vanes. The first mixer had a swirl angle of 45°, while the second had a swirl angle of 55°. In order to examine the effect …
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Laser shadowgraph study of early flame propagation in swirling flows near the lean misfire limit.
The effects of swirling flow and spark locations on the specific rate of growth of flame area, the flame speed and the convection velocity are investigated experimentally in a constant volume vessel near the lean misfire limit for an equivalence ratio of 0.645 using the shadowgraph technique. The …
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Impact of fuel and oxidizer composition on premixed flame stabilization in turbulent swirling flows : dynamics and scaling
… interaction between the flame and the turbulent swirling flow. Experimental data were used to construct the stability maps for different CH4-H2 mixtures and analyze the dynamic flame macrostructures and their transitions. A comparison with acoustically uncoupled combustion shows that the onset of …
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Quantitative Measurement of Velocity and Dispersion via Magnetic Resonance Imaging
Three pressure-driven flows of increasing complexity were examined, including flow through a water-saturated bed of randomly packed spheres, a Taylor-Couette-Poiseuille flow reactor, and the interstitial space between the blades of a rotating partitioned pipe mixer. Key findings show that a …
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Primary zone modeling for gas turbine combustors
Gas turbine combustor primary zone flows are typified by swirling flow with heat release in a variable area duct, where a central toroidal recirculation zone is formed. The goal of the research was to develop reduced-order models for these flows in an attempt to gain insight into, and understanding …
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Aerodynamic design of annular ducts
… having geometries capable of supporting fluid flows with prescribed performance characteristics. Three basic numerical methods of solution are given and are used to obtain results to the known exact solutions for a class of axisymmetric, irrotational incompressible flow regimes. Examination is …
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Fuel-NOx Formation during Low-Grade Fuel Combustion in a Swirling-Flow Burner
… of biomass tests in a pilot-scale (0.2 MW), swirling flow burner. Two-dimensional gas species mole fraction data were collected with state-of-theart instruments from nine experiments, composing one herbaceous biomass (straw), one woody biomass (sawdust), a low sulfur sub-bituminous coal …
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Effect of inlet configurations on the aerodynamics of swirl combustors
The flowfield in a swirling combustor with a Confinement Ratio of 1.6 was simulated in water. Qualitative measurements were made from flow visualization in a horizontal water rig with the help of Pliolite beads and liquid dye. Velocity and turbulence measurements were made in a cold air flow rig. …
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Thermoacoustic Analysis and Experimental Validation of Statistically-Based Flame Transfer Function Extracted from Computational Fluid Dynamics
… with a fixed τ. In practical systems, complex swirling flows, multiple fuel injections points, and recirculation zones create a distribution of τ, which can vary widely making a statistical description more representative. Furthermore, increased flame lengths and higher frequency instabilities …
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Unstructured mesh - finite volume algorithms for swirling, turbulent, reacting flows
… the case when there is more than one source of swirling flow. These original features contribute to a Computational Fluid Dynamics code which is capable of solving swirling, turbulent fluid flow and reactive, radiative heat transfer on highly complex geometries. Specifically the techniques are …
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The effect of swirl on the heat transfer downstream of sudden axi-symmetric expansions in a circular duct
… by increasing the jet momentum or by imparting a swirling motion to the burner fluids. Thus, the application of swirl is very common and there is also some evidence that it can lead to an increase in heat transfer to the load and walls of the enclosure. In most furnace applications radiation …
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Experimental Investigation of Flow and Wall Heat Transfer in an Optical Combustor for Reacting Swirl Flows
… better understanding of combustion in swirl flows and thermal energy transfer from the turbulent reacting flows to solid surfaces. Therefore, accurate measurement and prediction of the flows and heat loads are indispensable. This dissertation presents flow details and wall heat flux …
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A study on the flow characteristics of an industrial radiant tube burner
… and operation in addition to the theory behind swirling flows and methane combustion. NOx reduction techniques are discussed and numerical modelling of combusting flows is detailed in this section. The importance of turbulence, radiation and combustion modelling is highlighted, as well as the …
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Global stability and control of swirling jets and flames
… role in the dynamics of many practical flows, such as those found in gas turbine combustion chambers. This thesis is concerned primarily with large-scale unsteady structures that arise due to self-sustained hydrodynamic oscillations, also known as global hydrodynamic instability. Direct …
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