Numerical Computation and Validation of Two-Phase Flow Downstream of a Gas Turbine Combustor Dome Swirl Cup

1995 ◽  
Vol 117 (4) ◽  
pp. 704-712 ◽  
Author(s):  
A. K. Tolpadi ◽  
D. L. Burrus ◽  
R. J. Lawson
Keyword(s):  
Flow Field ◽  
Phase Velocity ◽  
Gas Turbine ◽  
Gas Phase ◽  
Frame Of Reference ◽  
Droplet Velocity ◽  
Phase Flow ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Good Agreement

The two-phase axisymmetric flow field downstream of the swirl cup of an advanced gas turbine combustor is studied numerically and validated against experimental Phase-Doppler Particle Analyzer (PDPA) data. The swirl cup analyzed is that of a single annular GE/SNECMA CFM56 turbofan engine that is comprised of a pair of coaxial counterswirling air streams together with a fuel atomizer. The atomized fuel mixes with the swirling air stream, resulting in the establishment of a complex two-phase flow field within the swirl chamber. The analysis procedure involves the solution of the gas phase equations in an Eulerian frame of reference using the code CONCERT. CONCERT has been developed and used extensively in the past and represents a fully elliptic body-fitted computational fluid dynamics code to predict flow fields in practical full-scale combustors. The flow in this study is assumed to be nonreacting and isothermal. The liquid phase is simulated by using a droplet spray model and by treating the motion of the fuel droplets in a Lagrangian frame of reference. Extensive PDPA data for the CFM56 engine swirl cup have been obtained at atmospheric pressure by using water as the fuel (Wang et al., 1992a). The PDPA system makes pointwise measurements that are fundamentally Eulerian. Measurements have been made of the continuous gas phase velocity together with discrete phase attributes such as droplet size, droplet number count, and droplet velocity distribution at various axial stations downstream of the injector. Numerical calculations were performed under the exact inlet and boundary conditions as the experimental measurements. The computed gas phase velocity field showed good agreement with the test data. The agreement was found to be best at the stations close to the primary venturi of the swirler and to be reasonable at later stations. The unique contribution of this work is the formulation of a numerical PDPA scheme for comparing droplet data. The numerical PDPA scheme essentially converts the Lagrangian droplet phase data to the format of the experimental PDPA. Several sampling volumes (bins) were selected within the computational domain. The trajectories of various droplets passing through these volumes were monitored and appropriately integrated to obtain the distribution of the droplet characteristics in space. The calculated droplet count and mean droplet velocity distributions were compared with the measurements and showed very good agreement in the case of larger size droplets and fair agreement for smaller size droplets.

scholarly journals Study of Two-Phase Flow Downstream of a Gas Turbine Combustor Dome Swirl Cup

1993 ◽  
Author(s):  
Anil K. Tolpadi ◽  
David L. Burrus ◽  
Robert J. Lawson
Keyword(s):  
Phase Velocity ◽  
Gas Turbine ◽  
Gas Phase ◽  
Frame Of Reference ◽  
Droplet Velocity ◽  
Computational Domain ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Number Count ◽  
Good Agreement

The two-phase axisymmetric flowfield downstream of the swirl cup of an advanced gas turbine combustor is studied numerically. The swirl cup analyzed is that of a single annular GE/SNECMA CFM56 turbofan engine that is comprised of a pair of coaxial counter-swirling air streams together with a fuel atomizer. The atomized fuel mixes with the swirling air stream resulting in the establishment of a complex two-phase flowfield within the swirl chamber. The analysis procedure involves the solution of the gas phase equations in a Eulerian frame of reference. The flow is assumed to be nonreacting and isothermal. The liquid phase is simulated by using a droplet spray model and by treating the motion of the fuel droplets in a Lagrangian frame of reference. Extensive Phase Doppler Particle Analyzer (PDPA) data for the CFM56 engine swirl cup has been obtained at atmospheric pressure by using water as the fuel (Wang et al., 1992a). This includes measurements of the gas phase velocity in the absence and presence of the spray together with the droplet size, droplet number count and droplet velocity distribution information at various axial stations downstream of the injector. Numerical calculations were performed under the exact inlet and boundary conditions as the experimental measurements. The computed gas phase velocity field showed good agreement with the test data. The agreement was found to be best at the stations close to the primary venturi of the swirler and to be reasonable at later stations. To compare the droplet data, a numerical PDPA scheme was formulated whereby several sampling volumes were selected within the computational domain. The trajectories of various droplets passing through these volumes were monitored and appropriately integrated. The calculated droplet count and mean droplet velocity distributions were compared with the measurements and showed very good agreement in the case of larger size droplets and fair agreement for smaller size droplets.

scholarly journals Scaling of the Two-Phase Flow Downstream of a Gas Turbine Combustor Swirl Cup: Part I—Mean Quantities

1993 ◽  
Vol 115 (3) ◽  
pp. 453-460 ◽  
Author(s):  
H. Y. Wang ◽  
V. G. McDonell ◽  
W. A. Sowa ◽  
G. S. Samuelsen
Keyword(s):  
Gas Turbine ◽  
Droplet Size ◽  
Continuous Phase ◽  
Droplet Velocity ◽  
Scale Model ◽  
Phase Flow ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Spatially Resolved ◽  
Phase Doppler Interferometry

A production gas turbine combustor swirl cup and a 3×-scale model (both featuring co-axial, counterswirling air streams) are characterized at atmospheric pressure. Such a study provides an opportunity to assess the effect of scale on the behavior of the continuous phase (gas in the presence of spray) and droplets by comparing the continuous phase velocity, droplet size, and droplet velocity at geometrically analogous positions. Spatially resolved velocity measurements of the continuous phase, droplet size, and droplet velocity were acquired downstream of the production and 3×-scale swirl cups by using two-component phase-Doppler interferometry in the absence of reaction. While the continuous phase flow fields scale well at the exit of the swirl cup, the similarity deviates at downstream locations due to (1) differences in entrainment, and (2) a flow asymmetry in the case of the production hardware. The droplet velocities scale reasonably well with notable exceptions. More significant differences are noted in droplet size, although the presence of the swirl cup assemblies substantially reduces the differences in size that are otherwise produced by the two atomizers when operated independent of the swirl cup.

Calculation of Two-Phase Flow in Gas Turbine Combustors

1995 ◽  
Vol 117 (4) ◽  
pp. 695-703 ◽  
Author(s):  
A. K. Tolpadi
Keyword(s):  
Gas Turbine ◽  
Gas Phase ◽  
High Power ◽  
Liquid Droplet ◽  
Frame Of Reference ◽  
Curvilinear Coordinates ◽  
Combustion Model ◽  
Gas Temperature ◽  
Two Phase ◽  
Phase Calculation

A method is presented for computing steady two-phase turbulent combusting flow in a gas turbine combustor. The gas phase equations are solved in an Eulerian frame of reference. The two-phase calculations are performed by using a liquid droplet spray combustion model and treating the motion of the evaporating fuel droplets in a Lagrangian frame of reference. The numerical algorithm employs nonorthogonal curvilinear coordinates, a multigrid iterative solution procedure, the standard k-ε turbulence model, and a combustion model comprising an assumed shape probability density function and the conserved scalar formulation. The trajectory computation of the fuel provides the source terms for all the gas phase equations. This two-phase model was applied to a real piece of combustion hardware in the form of a modern GE/SNECMA single annular CFM56 turbofan engine combustor. For the purposes of comparison, calculations were also performed by treating the fuel as a single gaseous phase. The effect on the solution of two extreme situations of the fuel as a gas and initially as a liquid was examined. The distribution of the velocity field and the conserved scalar within the combustor, as well as the distribution of the temperature field in the reaction zone and in the exhaust, were all predicted with the combustor operating both at high-power and low-power (ground idle) conditions. The calculated exit gas temperature was compared with test rig measurements. Under both low and high-power conditions, the temperature appeared to show an improved agreement with the measured data when the calculations were performed with the spray model as compared to a single-phase calculation.

scholarly journals Numerical Simulation of Gas-Particle Two-Phase Flow in a Nozzle with DG Method

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Duan Maochang ◽  
Yu Xijun ◽  
Chen Dawei ◽  
Qing Fang ◽  
Zou Shijun
Keyword(s):  
Flow Field ◽  
Gas Phase ◽  
Mass Fraction ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Governing Equations ◽  
Two Phase ◽  
Dg Method ◽  
The Impact

In this paper, the discontinuous Galerkin (DG) method is applied to solve the governing equations of the dispersed two-phase flow with the two-fluid Euler/Euler approach. The resulting governing equations are simple in form and the solution process is very natural. The characteristics of the gas-particle two-phase flow in an engine nozzle are mainly analyzed, and the impacts of the particle mass fraction and particle size on the flow field and engine performance are evaluated. Because of the addition of particles, the gas flow field undergoes significant modifications. Increase in the mass fraction leads to a significant thrust loss in the gas phase, and the impact of the particles on the gas phase could be substantial. Therefore, a quantitative study of thrust loss in the nozzle due to the particle impact is made. It is found that the gas thrust in the two-phase flow is reduced, but the total thrust of the two-phase flow increases to a certain extent.

OPTICAL MEASUREMENTS OF THE REACTING TWO-PHASE FLOW IN A REALISTIC GAS TURBINE COMBUSTOR AT ELEVATED PRESSURES

2006 ◽  
Vol 16 (5) ◽  
pp. 475-492 ◽  
Author(s):  
Thomas Behrendt ◽  
Martin Carl ◽  
Johannes Heinze ◽  
Christoph Hassa
Keyword(s):  
Gas Turbine ◽  
Two Phase Flow ◽  
Optical Measurements ◽  
Phase Flow ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Elevated Pressures

scholarly journals Scaling of the Two-Phase Flow Downstream of a Gas Turbine Combustor Swirl Cup: Mean Quantities

1992 ◽  
Author(s):  
H. Y. Wang ◽  
V. G. McDonell ◽  
W. A. Sowa ◽  
G. S. Samuelsen
Keyword(s):  
Gas Turbine ◽  
Droplet Size ◽  
Continuous Phase ◽  
Scale Model ◽  
Phase Flow ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Spatially Resolved ◽  
Phase Doppler Interferometry ◽  
The Difference

A production gas turbine combustor swirl cup and a 3x-scale model, both featuring co-axial, counter-swirling air streams are characterized at atmospheric pressure and in the absence of reaction. Spatially-resolved measurements of continuous phase (gas in the presence of spray) and droplet size and velocity are acquired downstream of the production and 3x-scale swirl cups by using two-component phase Doppler interferometry. The effect of scale on the behavior of the continuous phase and droplets is investigated by comparing the continuous phase velocity and droplet size and velocity at geometrically analogous positions. The continuous phase flow field scales well at the exit of the swirl cup. Farther downstream, differences occur which are due to disparity in entrainment. The droplet velocities scale reasonably well, but the sizes show some differences. However, the difference in size is less significant than it is between the two atomizers in the absence of the swirl cup assemblies.

Swirling Gas–Liquid Two-Phase Flow—Experiment and Modeling Part I: Swirling Flow Field

2004 ◽  
Vol 126 (6) ◽  
pp. 935-942 ◽  
Author(s):  
L. Gomez ◽  
R. Mohan ◽  
O. Shoham
Keyword(s):  
Flow Field ◽  
Two Phase Flow ◽  
Swirling Flow ◽  
Phase Flow ◽  
Centrifugal Forces ◽  
Two Phase ◽  
Cylindrical Cyclone ◽  
Flow Experiment ◽  
Core Characteristics ◽  
Good Agreement

Compact cyclonic separators are based on swirling flow, whereby the phases are separated due to the centrifugal forces generated by the flow. This phenomenon is common in several compact separators used by the oil, process, and aerospace industries. The objective of this paper is to study experimentally the hydrodynamics of the continuous liquid phase under swirling two-phase flow, such as that occurring in the lower part of the Gas–Liquid Cylindrical Cyclone (GLCC©1) compact separator and develop a model to characterize it. Local LDV measurements for a swirling flow field have been analyzed and utilized to develop cyclone and pipe swirling flow field prediction correlations. The developed correlations, including the axial, tangential, and radial velocity distributions, have been tested and validated against data from other studies, showing good agreement. The velocity field correlations can be used to analyze swirling two-phase flow in cyclonic separators and pipes. In part II of this two-part paper, correlations are developed for the turbulent quantities, and core characteristics and stability for swirling two-phase flow.

Investigation of the Two-Phase Flow Field of the GTX100 Compressor Inlet During Off-Line Washing

2004 ◽  
Author(s):  
Ulf Engdar ◽  
Raik C. Orbay ◽  
Magnus Genrup ◽  
Jens Klingmann
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Two Phase Flow ◽  
Ambient Air ◽  
Inlet Temperature ◽  
Phase Flow ◽  
Two Phase ◽  
Compressor Inlet ◽  
Program Star ◽  
On Line

A modern gas turbine compressor, with its highly aerodynamically loaded blades, is sensitive to changes in profile shape and to surface roughness. Fouling is inevitable, despite highly efficient filtration systems. The remedy to this problem is washing. There are two different approaches, on-line or off-line washing. The off-line wash is the most effective one, whilst on-line washing only prolongs the interval between off-line washes. Most findings in this field are highly empirical, being based on some 50 years of industrial gas turbine operation. This paper is an investigation of the two-phase flow in the bellmouth of the compressor during off-line washing conditions. The unit under study was the GTX100 turbo-set. Computational fluid dynamics (CFD) is used in this paper to perform a detailed study of the flow field. The main emphasis has been on studying the characteristics of the injected spray used for cleaning of the compressor. The benefit of heating this fluid is of special interest, since if this heating can be avoided, the outage time for the off-line compressor wash can be shortened. To provide the CFD computations with accurate boundary conditions for the spray, laser-based measurements of a spray, originating from an authentic wash nozzle, have been conducted. The commercial CFD program Star-Cd has been used for all computations. The computations show that the water injected, regardless of its inlet temperature, is cooled down to ambient air temperature well before the spray reaches the inlet guide vanes. This indicates that heating of the wash fluid can be abolished. The airflow seems not to be to influenced by the injected fluid to any great extend.

Sign in / Sign up

Export Citation Format

Share Document