Simulation of Airflow and Fuel Spray Through an Axial Swirler for Gas Turbine Applications

2008 ◽  
Author(s):  
Joshua E. Kempenaar ◽  
Kim A. Shollenberger ◽  
Gareth W. Oskam
Keyword(s):  
Gas Turbine ◽  
Cfd Simulation ◽  
Cross Flow ◽  
Fuel Spray ◽  
Fuel Injector ◽  
Discrete Phase Model ◽  
Flow Area ◽  
Jet In Cross Flow ◽  
Discrete Phase ◽  
Break Up

A computational fluid dynamics (CFD) simulation of the effects of an upstream blockage on the fuel spray and airflow through an axial swirler in an experimental gas turbine fuel injector has been conducted. Blockage was varied by means of varying the inside diameter of a restriction upstream of the entrance to the axial swirler. Fuel is injected as a jet in cross-flow through fuel nozzles located in axial swirler vanes. Fuel spray was modeled in the commercial CFD code Fluent 6.3.26 using the Lagrangian approach with the built-in Discrete Phase Model (DPM). Results are given for the TAB, Wave, and KH-RT break-up models. Preliminary simulations with the TAB break-up model were performed for a simple axisymmetric jet and compared to experimental results before simulating the axial swirler geometry. The axial swirler simulations predict that spray dispersion decreases and droplet size increases as the flow area of the blocker ring increases.

Experimental and Numerical Spray Characterization of a Gas Turbine Fuel Atomizer in Cross Flow

2002 ◽  
Author(s):  
F. A. Tap ◽  
A. J. Dean ◽  
J. P. Van Buijtenen
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Droplet Size ◽  
Cross Flow ◽  
Field Measurements ◽  
Fuel Injector ◽  
Ambient Conditions ◽  
Air Stream ◽  
Break Up

An experimental and numerical characterization of a macrolaminate pressure atomizer, placed perpendicularly to a high-velocity, turbulent air stream, is presented in this work. The purpose of the study was to compare detailed spray measurements with computations using a commercial CFD code. This study was part of the development of the premixing section of a midsize gas turbine, redesigned to meet low emissions and dual fuel market requirements. First, the spray characteristics were determined by injecting into a quiescent environment at ambient conditions. This data provided input for CFD calculations. Then the fuel injector was placed in a test section, at ambient conditions as well, that simulated the cross flow position of the atomizer in the prototype combustor. Droplet size and velocity were measured downstream of the injector nozzle, using a one-dimensional Phase Doppler Particle Analyzer. Measurements were done in two measuring planes. Flow field measurements were made to establish a common base for the computations. 2D computations were made of these experiments, using a k-ε turbulence model. The droplet trajectories were calculated with a Lagrangian ‘random walk’ technique, including drop break-up. The computed droplet size and velocity show agreement with the measurements. Drop break-up was also well represented by the model. The computed dispersion of the injected mass is not in agreement with the measured profile. This discrepancy in droplet dispersion is possibly due to high turbulence levels in the flow field, which were not well captured in the model.

CFD Simulation of Water Flow Mixing With Discrete Phase in a Pump

2013 ◽  
Author(s):  
Mikhail P. Strongin
Keyword(s):  
Particle Distribution ◽  
Cfd Simulation ◽  
Liquid Mixture ◽  
Industrial Applications ◽  
Discrete Phase Model ◽  
Water Transportation ◽  
Flow Mixing ◽  
Discrete Phase ◽  
The Subject ◽  
Pump Inlet

The mixing process is very common in many industrial applications. In some cases, two or more liquids or discrete phase (DP) set on the pump inlet. Liquid mixture is often occurred in sanitation and agriculture applications and mixture of water with DP (such as sand) are met in the case of water transportation from natural sources (rivers, wells, etc.). DP distribution in the centrifugal pump is the subject of this study. Full pump geometry is considered, due to unsymmetrical nature of volute of the pump. Turbulence k-ε closure model and Lagrangian discrete phase model has been used for most simulations. It was found that smaller particles trap inside the pump for longer time than larger ones. The distribution of the bigger diameter particles on the outlet is more asymmetrical in comparison with particles of smaller diameter. Relatively large areas with very small particle concentrations can be observed. Particle distribution on the outlet for lighter particles demonstrates more uniformity.

CFD Study on must of Grapes Separation in a Hydrocyclone

2013 ◽  
Vol 837 ◽  
pp. 645-650
Author(s):  
Petru Cârlescu ◽  
Ioan Tenu ◽  
Marius Baetu ◽  
Radu Rosca
Keyword(s):  
Cfd Simulation ◽  
Reynolds Stress Model ◽  
Continuous Phase ◽  
Solid Particles ◽  
Advanced Degree ◽  
Separation And Purification ◽  
Discrete Phase Model ◽  
Flow Rates ◽  
Discrete Phase ◽  
Simulation And Experiment

Abstract. Hydrocyclones are increasingly used in the food industry for various separation and purification. In this paper, an optimization was made to design a hydrocyclone model using CFD (Computational Fluid Dynamics). CFD simulation is performed with FLUENT software by coupling the Reynolds Stress Model (RSM) for must of grapes flow with Discrete Phase Model (DPM) for solid particles trajectory. Coupling of discrete phase (particles) and continuous phase (must of grapes) in the mathematical model is set so that the continuous phase to influence discrete phase. Tracking particles traiectory in this hydrocyclone allows advanced degree is separation so obtained to the maximum particle size approaching the size of a yeast cell 10 μm, without separating them. Hydrocyclone dimensional designed simulation was performed and analyzed on an experimental pilot plant for three different must flow rates supply. Introduced particle flow rates simulation and experiment does not exceed 10% of the must flow rates. The degree of separation obtained is in agreement with experimental data.

CFD Simulation of COVID Aerosol Dispersion in Indoor Environments

2021 ◽  
Author(s):  
Mohammed Abushamleh ◽  
Ning Zhang
Keyword(s):  
Relative Humidity ◽  
Cfd Simulation ◽  
Medium Size ◽  
Indoor Environments ◽  
Discrete Phase Model ◽  
Discrete Phase ◽  
Computational Fluid Dynamics Simulations ◽  
Aerosol Dispersion ◽  
Dynamics Simulations ◽  
Simulation Time

Abstract Computational Fluid Dynamics simulations for the droplet’s dispersion generated by a cough in an indoor background, droplets trajectory, and evaporation time are predicted to be related to the droplet’s diameter and relative humidity. In general, medium-size droplets have higher axial penetration potential, and large droplets tend to settle on the ground due to gravity. Also, larger droplets take a longer time to evaporate. Smaller droplets tend to be suspended in the flow field with small penetration potential and tend to fade faster; smaller droplets < 20 μm evaporate completely before the simulation time reaches 0.75 sec. To study the effect of Relative Humidity (RH) on the evaporation rate, in particular, the present study offers three simulations, all with the same standard room conditions, only differ in relative humidity s 40%, 60%, and 90%. Another source of variability is the cough-expired volume. This study adopts existent experimental work to establish two cough flow rate profiles. The Lagrangian discrete phase model is adopted along with the species model to track and investigate the cough droplet dispersion and evaporation.

Pratt and Whitney Gas Turbine Combustor Design Using ANSYS Fluent and User Defined Functions

2012 ◽  
Author(s):  
Baris A. Sen ◽  
Yanhu Guo ◽  
Randal G. McKinney ◽  
Federico Montanari ◽  
Frederick C. Bedford
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cross Flow ◽  
Product Family ◽  
Liquid Jet ◽  
Resource Requirement ◽  
Ansys Fluent ◽  
Systematic Testing ◽  
Jet In Cross Flow ◽  
Break Up

This paper summarizes work conducted at Pratt & Whitney to incorporate ANSYS Fluent into the computational fluid dynamics-based combustor design process. As a first step, turbulence, combustion and spray models that already exist and have been validated in the Pratt & Whitney legacy computational fluid dynamics (CFD) solver ALLSTAR were converted into user defined functions (UDFs) for usage with the core ANSYS Fluent solver. In this manner, a baseline solver was established that allowed a systematic testing of the ANSYS Fluent native models. The baseline solver was validated against computational results as well as experimental data obtained for (i) liquid jet in cross-flow (LJICF), (ii) ambient spray injector tests and (iii) Pratt & Whitney next generation product family configurations. These test cases established a thorough evaluation of ANSYS Fluent with UDFs on a spectrum of simple to complex geometries and flow physics relevant to the conditions encountered in aeroengine combustors. Results show that Fluent produces calculated results obtained by ALLSTAR with similar level of agreement to the experiments. Furthermore, Fluent provides better convergence compared to the legacy ALLSTAR solver with a similar computational resource requirement. The ANSYS Fluent native spray break-up models were also tested for the liquid jet in cross flow configuration, demonstrating the importance of modeling the stripping and primary break-up regime of a spray jet. This capability is currently available only via the use of UDFs.

scholarly journals Performance Characterization of the UAV Chemical Application Based on CFD Simulation

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 308 ◽  
Author(s):  
Hang Zhu ◽  
Hongze Li ◽  
Cui Zhang ◽  
Junxing Li ◽  
Huihui Zhang
Keyword(s):  
Wind Speed ◽  
Correlation Coefficient ◽  
Cfd Simulation ◽  
Least Square Method ◽  
Least Square ◽  
Universal Method ◽  
Discrete Phase Model ◽  
Chemical Application ◽  
Distance Model ◽  
Discrete Phase

Battery-powered multi-rotor UAVs (Unmanned Aerial Vehicles) have been employed as chemical applicators in agriculture for small fields in China. Major challenges in spraying include reducing the influence of environmental factors and appropriate chemical use. Therefore, the objective of this research was to obtain the law of droplet drift and deposition by CFD (Computational Fluid Dynamics), a universal method to solve the fluid problem using a discretization mathematical method. DPM (Discrete Phase Model) was taken to simulate the motion of droplet particles since it is an appropriate way to simulate discrete phase in flow field and can track particle trajectory. The figure of deposition concentration and trace of droplet drift was obtained by controlling the variables of wind speed, pressure, and spray height. The droplet drifting models influenced by different factors were established by least square method after analysis of drift quantity to get the equation of drift quantity and safe distance. The relationship model, Yi(m), between three dependent variables, wind speed Xw(m s−1), pressure Xp(MPa) and spray height Xh(m), are listed as follows: The edge drift distance model was Y1 = 0.887Xw + 0.550Xp + 1.552Xh − 3.906 and the correlation coefficient (R2) was 0.837; the center drift distance model was Y2 = 0.167Xw + 0.085Xp + 0.308Xh − 0.667 and the correlation coefficient (R2) was 0.774; the overlap width model was Y3 = 0.692xw + 0.529xp + 1.469xh − 3.374 and the correlation coefficient (R2) was 0.795. For the three models, the coefficients of the three variables were all positive, indicating that the three factors were all positively correlated with edge drift distance, center drift distance, and overlap width. The results of this study can provide theoretical support for improving the spray quality of UAV and reducing the drift of droplets.

scholarly journals Numerical Analysis of Nozzle Flow and Spray Characteristics from Different Nozzles Using Diesel and Biofuel Blends

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 281 ◽  
Author(s):  
M.H.H Ishak ◽  
Farzad Ismail ◽  
Sharzali Che Mat ◽  
M.Z. Abdullah ◽  
M.S. Abdul Aziz ◽  
...  
Keyword(s):  
Aerodynamic Drag ◽  
Flow Simulation ◽  
Nozzle Flow ◽  
Fuel Injector ◽  
Discrete Phase Model ◽  
Spray Cone ◽  
Discrete Phase ◽  
Nozzle Shape ◽  
Computer Fluid Dynamics ◽  
Spray Characteristic

In this paper, the discrete phase model (DPM) was introduced to study the fuel injector cavitations process and the macro spray characteristic of three different types of nozzle spray shape with diesel and hybrid biofuel blend for several injection pressures and backpressures. The three types of nozzle spray shapes used were circle, elliptical A type, and elliptical B type. The cavitations’ flows inside the injector nozzles were simulated with Computer Fluid Dynamics (CFD) simulations using the cavitations mixture approach. The effect of nozzle spray shape towards the spray characteristic of hybrid biofuel blends is analyzed and compared with the standard diesel. Furthermore, a verification and validation from both the experimental results and numerical results are also presented. The nozzle flow simulation results indicated that the fuel type did not affect the cavitation area vastly, but were more dependent on the nozzle spray shape. In addition, the spray width of the elliptical nozzle shape was higher as compared to the circular spray. Moreover, as the backpressure increased, the spray width downstream increased as well. The spray tip penetration for the elliptical nozzle shape was shorter than the circular nozzle shape due to circular nozzles having smaller nozzle widths and lesser spray cone angles. Thus, this resulted in smaller aerodynamic drag.

scholarly journals Staged combustion concept for gas turbines

2017 ◽  
Vol 1 ◽  
pp. CVLCX0 ◽  
Author(s):  
Dieter Winkler ◽  
Weiqun Geng ◽  
Geoffrey Engelbrecht ◽  
Peter Stuber ◽  
Klaus Knapp ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Cross Flow ◽  
Staged Combustion ◽  
Cfd Simulations ◽  
Flow Configuration ◽  
Turbulent Flame Speed ◽  
Second Stage ◽  
Jet In Cross Flow

AbstractGas turbine power plants with high load flexibility are particularly suitable to compensate power fluctuations of wind and solar plants. Conventional gas turbines suffer from higher emissions at low load operation. With the objective of improving this situation a staged combustion system has been investigated. At low gas turbine load an upstream stage (first stage) provides stable combustion at low emissions while at higher loads the downstream stage (second stage) is started to supplement the power. Three injection geometries have been studied by means of computational fluid dynamics (CFD) simulations and atmospheric tests. The investigated geometries were a simple annular gap, a jet-in-cross-flow configuration and a lobe mixer. With CFD simulations the quality of mixing of second stage fresh gas with first stage exhaust gas was assessed. The lobe mixer showed the best mixing quality and hence was expected to also be the best variant in terms of combustion. However atmospheric combustion tests showed lower emissions for the jet-in-cross-flow configuration. Comparing flame photos in the visible and ultraviolet (UV) range suggest that the flame might be lifted off for the lobe mixer, leading to insufficient time for carbon monoxide (CO) burnout. CFD analysis of turbulent flame speed, turbulence and strain rates support the hypotheses of lifted off flame. Overall the staged concept was found to show very promising results not only with natural gas but also with natural gas enriched with propane or hydrogen. The investigations showed that apart from having an efficient and compact mixing of the two stages it is also very important to design the flow field such that the second flame can be anchored properly in order to achieve compact flames with sufficient time for CO burnout.

scholarly journals Simulation of un industrial waste treatment tank

2020 ◽  
Vol 9 (4) ◽  
pp. e180942542
Author(s):  
Elcio Fernando Pereira ◽  
Luiz Mário Nelson Gois
Keyword(s):  
Petrochemical Industry ◽  
Cfd Simulation ◽  
Waste Treatment ◽  
Discrete Phase Model ◽  
Depth Data ◽  
Treatment Tank ◽  
Computational Mesh ◽  
Discrete Phase ◽  
Particles Trajectories ◽  
Lagrange Approach

The objective of the present work was to evaluate the operation of an industrial sedimentation tank used in the separation of solid waste from the petrochemical industry. The depth data were obtained through a “interface float”, while the diameters and the positions of the particles through the CFD simulation. The computational fluid dynamics simulator (FLUENT 6.3.26) was used to perform a multiphase simulation using the Euler-Lagrange approach and was used to determine the particles trajectories and cotours of solids accumulated in the bottom of the tank. This allowed a better understanding of solids accumulation and improvement of the cleaning process. In the simulation of the tank a large computational mesh comprising 464,094 computational nodes was designed. The use of the Euler-Lagrange approach meant that a discrete phase model had to be established and the parameters of Rosin-Rammler solids distribtion model for the boundary conditions of the simulation had to be determined. 

Sign in / Sign up

Export Citation Format

Share Document