3D-LDA diagnostics of a swirled flow in the model of an improved four-vortex furnace

The three-component Laser Doppler Anemometry method (3D-LDA) was used to study the internal aerodynamics of an experimental model of a promising furnace with a four-vortex scheme for burning coal fuel. Distributions of the averaged velocity and velocity fluctuations are obtained. There are no the pronounced peaks in the spectrum of velocity fluctuations, so we can speak about the stability of the investigated flow. The studied model is characterized by a high level of velocity fluctuations, provided for effective mixing of the pulverized coal mixture in the combustion chamber of the furnace.

Prediction of Gas Turbine Afterburner Performance Using CFD for Different Operating Conditions and Reheat Strength

A gas turbine afterburner is required to operate under severe conditions of pressure and temperature to meet the design requirements of next generation gas turbine engines. This fact, coupled with the current trends towards higher turbine discharge temperature and the requirement for satisfactory operation over extended fuel/air ratios and flight maps call for greater understanding of the internal aerodynamics for improving thrust developed by the afterburner. The present work focuses on prediction of performance of a practical afterburner for different altitude conditions and reheat strengths (i.e., fuel-air ratios) using Computational Fluid Dynamics (CFD) simulations. Combustion efficiency and thrust boost at these conditions have been predicted. The reacting flow field has been analyzed and changes suggested for improving thrust at low performance points.

Parametric Effects on Internal Aerodynamics of Lobed Mixer-Ejector With Curved Mixing Duct

The internal flow characteristics inside lobed mixer-ejector with curved mixing duct and the parametric effects on the lobed mixer-ejector performance are investigated numerically and validated by experimental test. The curved mixing duct affects the development of the streamwise vortices induced by the lobed mixer. When the mixing process undergoes the transition from the straight section to the bent section, the flow inside the curved mixing duct is dominated by the impinging and centrifugal effects. In general, the pumping ratio is decreased approximately 20%–30% once the bent section is mounted on the straight duct. The mixer-ejector performance could by improved by increasing the straight section length, due to more fully momentum utilization of primary jet and weaker influence of bent section on the back pressure near nozzle exit. The mixer-ejector pumping capacity is also augmented with the increase of mixing duct area ratio until the area ratio is reached to 3.5. And the fully-utilization of primary jet momentum inside mixing duct with big area ratio needs long mixing distance. The pumping ratio is decreased as the increase of bent angle of curved mixing duct in approximately linear relationship. When the bent angle exceeds 45 deg, the thermal mixing efficiency is decreased rapidly as the increase of bent angle.

Physical and Numerical Modelling of Internal Aerodynamics of the Vortex Furnace with Distributed Tangential Input of Burner Streams

The work is devoted to experimental and numerical modelling of internal aerodynamics of a new type furnace for the thermal power plant steam generator with technology of pulverized-coal combustion in vortex flow. Measurements of aerodynamic features of the flow in the laboratory air isothermal model of the furnace have been performed with twocomponent laser Doppler velocimeter. Numerical simulation of three-dimensional turbulent isothermal flow in the laboratory model has been carried out with the use of CFD package FLUENT. Detailed 3-D flow structure in the studied model has been obtained. The agreement between numerical predictions and measurements on mean flow velocity distributions has been shown