scholarly journals COMBUSTION OF ALUMINUM POWDER-AIR SUSPENSION IN A SWIRL FLOW

2021 ◽  
Vol 18 (2) ◽  
pp. 47-55
Author(s):  
K.M. Moiseeva ◽  
Keyword(s):  
Combustion Chamber ◽  
Aluminum Powder ◽  
Swirling Flow ◽  
Mathematical Formulation ◽  
Axial Flow ◽  
Swirl Flow ◽  
Sudden Expansion ◽  
Two Phase ◽  
Air Suspension ◽  
Numerical Parametric Study

The article is devoted to the numerical solution of the problem of the combustion of powder metal fuel in a combustion chamber with swirling flow. A physico-mathematical model of the flow of an air suspension of aluminum powder in a swirling flow in a cylindrical combustion chamber with a sudden expansion is presented. The physical and mathematical formulation of the problem is based on the approaches of the mechanics of two-phase reacting media. The solution was carried out using the arbitrary discontinuity decay method. The results of a numerical parametric study of the features of the combustion of an air suspension of aluminum powder depending on its composition, the axial flow rate of the mixture at the entrance to the combustion chamber, and the value of the swirl speed are shown.

INFLUENCE OF FLOW SWIRLING ON COMBUSTION OF ALUMINUM POWDER AEROSUSPENSION IN A CHAMBER WITH EXTENSION

2020 ◽  
Author(s):  
A. Yu. Krainov ◽  
◽  
K. M. Moiseeva ◽  
V. A. Poryazov ◽  
◽  
...  
Keyword(s):  
Dynamic Model ◽  
Aluminum Powder ◽  
Swirling Flow ◽  
Numerical Study ◽  
Mathematical Formulation ◽  
Expansion Chamber ◽  
Flow Swirling ◽  
Air Suspension

A numerical study of combustion of the aluminum-air suspension in the swirling flow in the expansion chamber has been performed. The physical and mathematical formulation of the problem is based on the dynamic model of the multiphase reacting media.

Experimental Analysis on the Formation of CO-NO-HC in Swirling Flow Combustion Chamber

2015 ◽  
Vol 72 (4) ◽  
Author(s):  
Mohamad Shaiful Ashrul Ishak ◽  
Mohammad Nazri Mohd. Jaafar ◽  
Wan Zaidi Wan Omar
Keyword(s):  
Combustion Chamber ◽  
Swirling Flow ◽  
Swirl Flow ◽  
Recirculation Region ◽  
Mixing Rate ◽  
Swirl Angle ◽  
Low Emission ◽  
Air Mixing ◽  
Efficient Combustion ◽  
Hc Emissions

The main purpose of this paper is to evaluate the production of CO-NO-HC emissions while varying the swirl angle of curve vane radial swirler. Swirling flow generates central recirculation region (CRZ) which is necessary for flame stability and enhances fuel air mixing. Therefore designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion inside burner system. Four radial curved vane swirlers with 30o, 40o, 50o and 60o vane angles corresponding to swirl numbers of 0.366, 0.630, 0.978 and 1.427 respectively were used in this experiment to measure the vane angles effect on emission production in the combustion chamber. Emission measurements were conducted at 5 axial distances from the burner throat, and at 5 locations along the radius starting the central axis at each section. It was found that at the core near the throat, CO and HC concentrations are low due to high available O2 and high fuel mixing rate producing efficient combustion. This is due to the high shear region created the high swirl flow.

Two-Phase Flow Patterns and Pressure Drop Inside a Vertical Pipe Containing a Short Helical Tape Insert

2014 ◽  
Author(s):  
Wen Liu ◽  
Bofeng Bai
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Swirling Flow ◽  
Large Diameter ◽  
Experimental Studies ◽  
Flow Patterns ◽  
Swirl Flow ◽  
Phase Flow ◽  
Vertical Pipe ◽  
Two Phase

Swirling gas-liquid two-phase flow patterns and pressure drop in vertical pipes of a large diameter are widely present in practical applications but not well documented in experimental studies. This paper presented an experimental study on gas-liquid two phase flow patterns and pressure drop inside a vertical pipe of 62mm in inner diameter (ID) containing a helical tape insert. Experimental results were obtained in a vertical visualization test section with a length of 7m, liquid mass velocities ranging from 0.3 to 1000 kg/(m2·s), and gas mass velocities from 3.2 to 900kg/(m2·s). Considering the decay of the swirl flow, the swirling flow regime map at different cross sections (z/D = 16, 32 and 64) were concluded, and their effects on the pressure drop were investigated.

scholarly journals Effect of swirl flow on the performance of parallel hub axial annular diffuser

2021 ◽  
Author(s):  
Hardial Singh ◽  
◽  
Arora B.B ◽  
Keyword(s):  
Swirling Flow ◽  
Cone Angle ◽  
Axial Flow ◽  
Swirl Flow ◽  
Recovery Coefficient ◽  
Pressure Loss Coefficient ◽  
Swirl Angle ◽  
Annular Diffuser ◽  
Inlet Swirl ◽  
Result Analysis

In the present work, the parallel hub axial flow annular diffuser's performance characteristics with divergent casing varying between equivalent cone angle (10°, 15°, and 20°) with area ratio 3 have been evaluated computationally as well as experimentally. The performance of three diffusers were tested at different inlet swirl angles (from 0° to 25°) for swirling and non-swirling flow. Simulations have been carried out on a fully developed flow at Reynolds number 2.5×105. The results were analyzed based on the velocity profiles, static pressure recovery coefficient, and the total pressure loss coefficient. The result analysis shows that the inlet swirl flow improves the recovery of pressure and also delays the flow separation on the casing. Moreover,the findings also show that the best performance was achieved in equivalent cone angle 10° at the inlet swirl angle of 7.5° compared to other diffusers.

Numerical simulation of swirling flow effect on the first stage vane film cooling distribution

2016 ◽  
Vol 07 (03) ◽  
pp. 1650031
Author(s):  
Hong Yin
Keyword(s):  
Flow Field ◽  
Film Cooling ◽  
Swirling Flow ◽  
Cooling System ◽  
Leading Edge ◽  
Suction Side ◽  
Local Area ◽  
Swirl Flow ◽  
Flow Effect ◽  
Recirculation Flow

In advanced gas turbine technology, lean premixed combustion is an effective strategy to reduce peak temperature and thus, NO[Formula: see text] emissions. The swirler is adopted to establish recirculation flow zone, enhancing mixing and stabilizing the flame. Therefore, the swirling flow is dominant in the combustor flow field and has impact on the vane. This paper mainly investigates the swirling flow effect on the turbine first stage vane cooling system by conducting a group of numerical simulations. Firstly, the numerical methods of turbulence modeling using RANS and LES are compared. The computational model of one single swirl flow field is considered. Both the RANS and LES results give reasonable recirculation zone shape. When comparing the velocity distribution, the RANS results generally match the experimental data but fail to at some local area. The LES modeling gives better results and more detailed unsteady flow field. In the second step, the RANS modeling is incorporated to investigate the vane film cooling performance under the swirling inflow boundary condition. According to the numerical results, the leading edge film cooling is largely altered by the swirling flow, especially for the swirl core-leading edge aligned case. Compared to the pressure side, the suction side film cooling is more sensitive to the swirling flow. Locally, the film cooling jet is lifted and turned by the strong swirling flow.

Experimental Characterization of Two-Phase Swirl Flow Interacting With a Circular Bluff Body

2021 ◽  
Author(s):  
Rafael Gonzalez Hernandez ◽  
Afshin Goharzadeh ◽  
Mahmoud Meribout ◽  
Lyes Khezzar
Keyword(s):  
High Speed ◽  
Bluff Body ◽  
Transition Period ◽  
Swirl Flow ◽  
Critical Distance ◽  
High Speed Photography ◽  
Flow Loop ◽  
Two Phase ◽  
Air Pocket ◽  
Air Core

Abstract This study presents an experimental investigation of two-phase swirl flow interacting with a circular bluff body. A horizontal and transparent multiphase flow loop is employed to investigate the dynamic of swirl flow close to the circular bluff body. Using high-speed photography, air-core development during the transition period is characterized. Analysis of both instantaneous and averaged images provides key information on air-core length and diameter for steady state conditions. The distance from air-core tip to the disk depends on a critical gas-liquid ratio (GLRc). The presence of air pocket behind the circular bluff body depends on a critical distance to the disk.

COMBUSTION OF A GAS SUSPENSION OF COAL DUST IN A SWIRLING FLOW

2021 ◽  
pp. 139-147
Author(s):  
K.M. Moiseeva ◽  
◽  
A.Yu. Krainov ◽  
E.I. Rozhkova ◽  
◽  
...  
Keyword(s):  
Flow Velocity ◽  
Swirling Flow ◽  
Coal Dust ◽  
Combustion Efficiency ◽  
Dust Particles ◽  
Gas Temperature ◽  
Flow Swirl ◽  
Angular Component ◽  
Air Suspension ◽  
The Impact

Swirling combustion is currently one of the most important engineering problems in physics of combustion. There is a hypothesis on the increase in the combustion efficiency of reacting gas mixtures in combustion chambers with swirling flows, as well as on the increase in the efficiency of fuel combustion devices. In this paper, it is proposed to simulate a swirling flow by taking into account the angular component of the flow velocity. The aim of the study is to determine the effect of the angular component of the flow velocity on the characteristics of the flow and combustion of an air suspension of coal dust in a pipe. The problem is solved in a twodimensional axisymmetric approximation with allowance for a swirling flow. A physical and mathematical model is based on the approaches of the mechanics of multiphase reacting media. A solution method involves the arbitrary discontinuity decay algorithm. The impact of the flow swirl and the size of coal dust particles on the gas temperature distribution along the pipe is determined.

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