scholarly journals Effect of acoustic perturbation on particle dispersion in a swirl-stabilized pulverized fuel burner: Cold-flow conditions

2022 ◽  
Vol 228 ◽  
pp. 107142
Author(s):  
Marcelo Dal Belo Takehara ◽  
Ángel David García Llamas ◽  
Muhammad Aqib Chishty ◽  
Kentaro Umeki ◽  
Rikard Gebart
Keyword(s):  
Particle Dispersion ◽  
Flow Conditions ◽  
Cold Flow ◽  
Acoustic Perturbation ◽  
Pulverized Fuel ◽  
Fuel Burner

Numerical Studies on Trapped-Vortex Concepts for Stable Combustion

1998 ◽  
Vol 120 (1) ◽  
pp. 60-68 ◽  
Author(s):  
V. R. Katta ◽  
W. M. Roquemore
Keyword(s):  
Drag Coefficient ◽  
Reacting Flow ◽  
Flow Conditions ◽  
Third Order ◽  
Cold Flow ◽  
Flow Simulations ◽  
Numerical Studies ◽  
Dynamic Flows ◽  
Experimental Findings ◽  
Trapped Vortex

Spatially locked vortices in the cavities of a combustor aid in stabilizing the flames. On the other hand, these stationary vortices also restrict the entrainment of the main air into the cavity. For obtaining good performance characteristics in a trapped-vortex combustor, a sufficient amount of fuel and air must be injected directly into the cavity. This paper describes a numerical investigation performed to understand better the entrainment and residence-time characteristics of cavity flows for different cavity and spindle sizes. A third-order-accurate time-dependent Computational Fluid Dynamics with Chemistry (CFDC) code was used for simulating the dynamic flows associated with forebody-spindle-disk geometry. It was found from the nonreacting flow simulations that the drag coefficient decreases with cavity length and that an optimum size exists for achieving a minimum value. These observations support the earlier experimental findings of Little and Whipkey (1979). At the optimum disk location, the vortices inside the cavity and behind the disk are spatially locked. It was also found that for cavity sizes slightly larger than the optimum, even though the vortices are spatially locked, the drag coefficient increases significantly. Entrainment of the main flow was observed to be greater into the smaller-than-optimum cavities. The reacting-flow calculations indicate that the dynamic vortices developed inside the cavity with the injection of fuel and air do not shed, even though the cavity size was determined based on cold-flow conditions.

scholarly journals Investigation of the Flow In Cold Condition at the Exit of a Supersonic Combustor Test Bench

2020 ◽  
Author(s):  
Jefte da Silva Guimarães ◽  
Valéria Serrano Faillace Oliveira Leite ◽  
Dermeval Carinhana Junior ◽  
Marco Antônio Sala Minucci
Keyword(s):  
Nozzle Exit ◽  
Test Bench ◽  
Supersonic Combustion ◽  
Flow Conditions ◽  
Circular Section ◽  
Cold Flow ◽  
Ground Test ◽  
Cold Condition ◽  
Transition Piece ◽  
Generator Unit

For studies of hypersonic flows and supersonic combustion in ground test facilities, three devices can be used as ram accelerators, shock tunnels and supersonic combustor test benches. These devices can reproduce, on the ground, similar conditions to those in real flight at a certain altitude and speed. In the case of the supersonic combustor test bench (SCTB), it simulates the same flow conditions inside the combustor of a scramjet. The SCTB consists basically of a combustion chamber or vitiated air generator unit, where the air is heated, and a nozzle, where the air is accelerated to the desired test speed. The supersonic combustor to be tested is directly coupled to the nozzle exit of the SCTB. Ultimately, it was necessary to use a transition piece to connect the nozzle to the combustor to be tested, because the nozzle exit has a circular section and the combustor entrance has a rectangular one. This work aims to present the process of characterizing the cold flow along the SCTB of the Institute for Advanced Studies (IEAv) using the schlieren technique. The interference of the transition piece in obtaining the required flow conditions at the exit of the SCTB or the entrance of the combustor was mainly evaluated.

scholarly journals Comparison between Hot and Cold Flow Conditions of Turbine Cascade

2010 ◽  
Vol 53 (181) ◽  
pp. 171-179 ◽  
Author(s):  
Mahmoud M. EL-GENDI ◽  
Katsunori DOI ◽  
Mohammed K. IBRAHIM ◽  
Koichi MORI ◽  
Yoshiaki NAKAMURA
Keyword(s):  
Turbine Cascade ◽  
Flow Conditions ◽  
Cold Flow

Temperature Effect on Particle Dynamics and Erosion in Radial Inflow Turbine

1988 ◽  
Vol 110 (2) ◽  
pp. 258-264 ◽  
Author(s):  
W. Tabakoff ◽  
A. Hamed
Keyword(s):  
Temperature Effect ◽  
Gas Turbines ◽  
Particle Dynamics ◽  
Flow Conditions ◽  
Inlet Flow ◽  
Cold Flow ◽  
Erosion Rates ◽  
Radial Inflow Turbine ◽  
Turbine Rotors

This paper presents the results of an investigation of the particle dynamics and the resulting blade erosion in radial inflow turbine rotors. In order to determine the influence of the temperature, the computations were performed for cold and hot inlet flow conditions. The results indicate that the trajectories of these small 5-μm ash particles are quite sensitive to the flow temperatures. In addition, gas turbines operating under hot flow are subjected to higher local blade erosion rates compared to cold flow conditions.

Achieving cold flow conditions for ‘waxy’ mixtures with minimum solid deposition

Fuel ◽  
2019 ◽  
Vol 235 ◽  
pp. 1092-1099 ◽  
Author(s):  
Samira Haj-Shafiei ◽  
Anil K. Mehrotra
Keyword(s):  
Flow Conditions ◽  
Cold Flow ◽  
Solid Deposition

The Analysis of the Impact of Particles on Cavitation Flow Development

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Boštjan Gregorc ◽  
Matjaž Hriberšek ◽  
Andrej Predin
Keyword(s):  
Dispersion Model ◽  
Phase Particle ◽  
Experimental Studies ◽  
Particle Dispersion ◽  
Solid Particles ◽  
Cavitation Flow ◽  
Flow Conditions ◽  
Cavitation Tunnel ◽  
The Impact ◽  
Additional Phase

The purpose of this paper is to present an analysis of the impact of solid particles on the development of cavitation flow conditions around a hydrofoil. Experimental studies were conducted in a cavitation tunnel with different mixtures of particles and water. The effect of the particles on the development of cavitation flows was modeled by using an additional phase particle dispersion model (Euler-Euler). Numerical modeling was performed using the CFD software. The impact on the cavity model with the parametric analysis of the entry conditions of particles in the calculation domain was investigated, with a focus on the solid shear viscosity. Another purpose of this research was to present the possibility of modeling the development of the vapor phase in the commercial CFD software package, while taking into account the impact of particles. This paper presents the results of the experimental measurements and their comparison with numerical simulations.

Improvement of Aerodynamic Performance of a Combustor Dump Diffuser Using Inclined Walls

2000 ◽  
Author(s):  
Shinji Honami ◽  
Eiichi Yamazaki ◽  
Takaaki Shizawa
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Aerodynamic Performance ◽  
Total Pressure Loss ◽  
Flow Conditions ◽  
Mean Velocity ◽  
Cold Flow ◽  
Inlet Distortion ◽  
Flow Experiment ◽  
The Mean

The combustor diffuser with the deep flame dome in the recent engine results in the large total pressure loss. It is important to obtain both better aerodynamic performance by reduction of total pressure loss and reduced NOx in the exhaust from the combustor, regardless of the inlet flow conditions such as inlet distortion. Installation of an inclined wall within the combustor dump diffuser is suggested in order to improve the aerodynamic performance. A cold flow experiment using Pitot probe surveys in a model of a combustor diffuser shows that the inclined wall is effective in improvement of the total pressure loss, even if the velocity profile at the diffuser inlet is distorted. Furthermore, the flow rate distributions into the branched channels are also improved. The flow mechanism in the inclined wall configuration is clarified from the measurements of the mean velocity and turbulent Reynolds stress by a Laser Doppler Velocimetry (LDV) system.

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