Combined Experimental - Numerical Approach for the Fuel Jet Study in a LPP Combustor

2011 ◽  
Author(s):  
Amedeo Amoresano ◽  
Maria Cristina Cameretti ◽  
Raffaele Tuccillo
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Numerical Approach ◽  
Experimental Information ◽  
Liquid Fuels ◽  
Injection System ◽  
Spray Parameters ◽  
Flow Solver ◽  
Fuel Jet ◽  
Fuel Vapour

The purpose of the paper is the investigation of the phenomena that mainly affect the mixture preparation and the combustion development in lean-premixed chambers supplied with liquid fuels (LPP). In such a study, the experimental analysis, performed by PDA based measurements, is supported and addressed by a CFD tool that is able to simulate the injection conditions, by isolating and studying some specific phenomena. A 3-D fluid dynamic code (i.e., the FLUENT® flow solver) has been used to simulate the spray pattern in the chamber. Preliminarily, the numerical simulation refer to cold flow conditions, in order to validate the estimation of the fundamental spray parameters through the comparison with the experimental data; in a second step, the calculations employ boundary conditions close to those occurring in the actual combustor operation, in order to predict the fuel vapour distribution throughout the premixing chamber. In particular, the fuel is injected under the typical conditions that occur in the injection system of a gas turbine LPP combustor. In this phase, the experimental information are introduced in terms of air and fuel mass flow rates and of inlet characteristics of the air flow entering the prevaporizing chamber, in order to predict the fuel vapour formation and distribution. The paper also compares different approaches that have been experienced for the CFD simulation.

Numerical Investigation of Spray Development in a Micro Gas Turbine LPP Combustor With Airblast Atomizer

2018 ◽  
Author(s):  
Gianluca Annunziata ◽  
Maria Cristina Cameretti ◽  
Roberta De Robbio ◽  
Raffaele Tuccillo
Keyword(s):  
Gas Turbine ◽  
Fluid Dynamic ◽  
Liquid Fuels ◽  
Spray Angle ◽  
Injection System ◽  
Spray Parameters ◽  
Flow Solver ◽  
Micro Gas Turbine ◽  
Mass Flow Rates ◽  
Fuel Vapour

The purpose of the paper is the investigation of the combustion development in a Lean Premixed Prevaporized (LPP) combustor supplied with liquid fuels of a Micro Gas Turbine. The injection system is equipped by an airblast atomizer with three air inlets. In such a study the analysis is performed by a CFD tool that can simulate the injection conditions, by isolating and studying some specific phenomena. A 3-D fluid dynamic code (the FLUENT® flow solver) has been used to simulate the spray pattern in the chamber fuelled by kerosene fuel. Preliminarily, the numerical simulation refers to cold flow conditions, in order to validate the estimation of the fundamental spray parameters, such as the spray angle and Sauter Mean Diameter of the droplets; in a second step, the calculations employ boundary conditions close to those occurring in the actual combustor operation, in order to predict the fuel vapour distribution throughout the premixing chamber. In particular, the fuel is injected under the typical conditions that occur in the injection system of a gas turbine LPP combustor and in all cases examined, the boundary information is introduced in terms of air and fuel mass flow rates and of inlet characteristics of the air flow entering the revalorizing chamber, in order to estimate the fuel vapour formation and its distribution. In a third phase the combustion phenomenon is simulated and the NO emissions calculated. Finally, the best solution obtained is also tested by using a bio-fuel to compare the combustion performance and NO amount.

A Numerical Study of Spray Injected in a Gas Turbine Lean Pre-Mixed Pre-Vaporized Combustor

2015 ◽  
Vol 32 (1) ◽  
Author(s):  
Amedeo Amoresano ◽  
Maria Cristina Cameretti ◽  
Raffaele Tuccillo
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Spray Parameters ◽  
Flow Conditions ◽  
Gas Turbine Combustor ◽  
Flow Solver ◽  
Combustion Simulation ◽  
Fuel Vapour

AbstractThe authors have performed a numerical study to investigate the spray evolution in a modern gas turbine combustor of the Lean Pre-Mixed Pre-vaporized type. The CFD tool is able to simulate the injection conditions, by isolating and studying some specific phenomena. The calculations have been performed by using a 3-D fluid dynamic code, the FLUENT flow solver, by choosing the injection models on the basis of a comparative analysis with some experimental data, in terms of droplet diameters, obtained by PDA technique.In a first phase of the investigation, the numerical simulation refers to non-evaporating flow conditions, in order to validate the estimation of the fundamental spray parameters. Next, the calculations employ boundary conditions close to those occurring in the actual combustor operation, in order to predict the fuel vapour distribution throughout the premixing chamber. The results obtained allow the authors to perform combustion simulation in the whole domain.

The Role of Simulation in the Development of a Fast-Actuation Solenoid C.R. Injection System

2004 ◽  
Author(s):  
Gian Marco Bianchi ◽  
Piero Pelloni ◽  
Giovanni Osbat ◽  
Marco Parotto ◽  
Rita Di Gioia ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Control Strategies ◽  
Fluid Dynamic ◽  
Numerical Approach ◽  
Linear Analysis ◽  
Operating Conditions ◽  
System Model ◽  
Injection System ◽  
Multiple Injection ◽  
Pressure Regulator

Upcoming Euro 4 and Euro 5 emission standards are increasing efforts on injection system developments in order to improve mixture quality and combustion efficiency. The target features of advanced injection system are related to their capability of operating multiple injection with a precise control of amount of fuel injected, low cycle-by-cycle variability and life drift, within flexible strategies. In order to accomplish this task, performance must be optimised since injection system concept development by acting on. The extensive use of numerical approach has been identified as a necessary integration to experiments in order to put on the market high quality injection system accomplishing strict engine control strategies. The modelling approach allows focusing the experimental campaign only on critical issues saving time and costs, furthermore it is possible to deeply understand inner phenomena that cannot be measured. The lump/ID model of the whole system built into the AMESim® code was presented in previous works: particular attention was devoted in the simulation of the electromagnetic circuits, actual fluid-dynamic forces acting on needle surfaces and discharge coefficients, evaluated by means 3D-CFD simulations. In order to assess new injection system dynamic response under multiple injection strategies reproducing actual engine operating conditions it is necessary to find to proper model settings. In this work the integration between the injector and the system model, which comprehends the pump, the pressure regulator, the rail and the connecting-pipes, will be presented. For reproducing the dynamic response of he whole system will be followed a step-by-step approach in order to prevent modelling inaccuracies. Firstly will be presented the linear analysis results performed in order to find injection system own natural frequencies. Secondly based on linear analysis results will be found proper injection system model settings for predicting dynamic response to external excitations, such as pump perturbations, pressure regulator dynamics and injection pulses. Thirdly experimental results in terms of instantaneous flow rate and integrated injected volume for different operating conditions will be presented in order to highlight the capability of the modelling methodology in addressing the new injection system design.

Analysis of Temperature and Residence Time of the Exhausts in the Combustion Chamber of an Incinerator Plant

2008 ◽  
Author(s):  
M. Costa ◽  
M. Dell’Isola ◽  
N. Massarotti ◽  
A. Mauro
Keyword(s):  
Combustion Chamber ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Waste Incineration ◽  
Numerical Approach ◽  
Full Scale ◽  
Practical Applications ◽  
The Common ◽  
Semi Empirical ◽  
The Impact

The interest for energy recovery from waste incineration has increased over the years, in order to reduce the number of landfills and produce electricity and heat. At the same time, concern for the impact such processes have on the environment has also grown, and to reduce such an impact, new legislation is being enforced in Europe and Italy. In particular, important restrictions are imposed on the temperature of the exhausts in the combustion chamber, which must be kept above certain values for a given period of time, depending on the type of waste that is being incinerated. Such conditions can be rather difficult and certainly very expensive to monitor with acceptable accuracy. For this reason, in practical applications the temperature of the exhausts in the chamber is usually calculated through semi-empirical and approximate models that relate the temperatures in different sections of the chamber. In this work, the authors present a numerical approach for the analysis of such models that can be used to quantify the uncertainty on this type of measurement due to the common approximations used in full scale incineration plants. The analysis is based on the CFD simulation of the thermo-fluid-dynamic field in the combustion chamber of a full scale plant in Italy, whose results have verified based on a comparison with the data collected during an experimental campaign.

Modeling the Effect of Nozzle Hole Geometry on Diesel Injection and Combustion

2010 ◽  
Author(s):  
G. Chiatti ◽  
O. Chiavola ◽  
F. Palmieri
Keyword(s):  
Cfd Simulation ◽  
Fuel Injection ◽  
Injection System ◽  
Jet Formation ◽  
Diesel Injection ◽  
Step Procedure ◽  
Fuel Jet ◽  
Flow Features ◽  
Nozzle Hole ◽  
Subsequent Phase

The performance of the ensemble diesel engine-injection system has been investigated by modeling; different approaches have been combined and integrated in a multi step procedure. In a preliminary phase, the nozzle flow features have been investigated by means of 3D CFD simulation (FIRE), allowing for the evaluation of nozzle hole discharge coefficients. Such values have been used in the subsequent phase, based on a 0/1D approach, in which the complete model of the fuel injection system has been realized and the injected fuel amounts have been evaluated. On the basis of these indications, a further simulation phase has been included and a packet model for the modeling of fuel jet formation, evaporation and combustion has been built and used. In-cylinder pressure trends have been obtained and the effects of different nozzle hole geometries have been investigated.

scholarly journals Impeller Optimization in Crossflow Hydraulic Turbines

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 313
Author(s):  
Marco Sinagra ◽  
Calogero Picone ◽  
Costanza Aricò ◽  
Antonio Pantano ◽  
Tullio Tucciarelli ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Structural Safety ◽  
3D Fem ◽  
Good Efficiency ◽  
Standard Material ◽  
Variable Head ◽  
Hydraulic Turbines ◽  
Constructive Simplicity ◽  
Mechanical Optimization

Crossflow turbines represent a valuable choice for energy recovery in aqueducts, due to their constructive simplicity and good efficiency under variable head jump conditions. Several experimental and numerical studies concerning the optimal design of crossflow hydraulic turbines have already been proposed, but all of them assume that structural safety is fully compatible with the sought after geometry. We show first, with reference to a specific study case, that the geometry of the most efficient impeller would lead shortly, using blades with a traditional circular profile made with standard material, to their mechanical failure. A methodology for fully coupled fluid dynamic and mechanical optimization of the blade cross-section is then proposed. The methodology assumes a linear variation of the curvature of the blade external surface, along with an iterative use of two-dimensional (2D) computational fluid dynamic (CFD) and 3D structural finite element method (FEM) simulations. The proposed methodology was applied to the design of a power recovery system (PRS) turbine already installed in an operating water transport network and was finally validated with a fully 3D CFD simulation coupled with a 3D FEM structural analysis of the entire impeller.

scholarly journals Computational fluid dynamics (CFD) simulation analysis on retinal gas cover rates using computational eye models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Makoto Gozawa ◽  
Yoshihiro Takamura ◽  
Tomoe Aoki ◽  
Kentaro Iwasaki ◽  
Masaru Inatani
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Fluid Dynamic ◽  
Fluid Analysis ◽  
Intraocular Gas ◽  
Pars Plana ◽  
Computational Fluid Dynamics Cfd ◽  
Multiple Breaks ◽  
Gas Volume ◽  
Wall Wettability

AbstractWe investigated the change in the retinal gas cover rates due to intraocular gas volume and positions using computational eye models and demonstrated the appropriate position after pars plana vitrectomy (PPV) with gas tamponade for rhegmatogenous retinal detachments (RRDs). Computational fluid dynamic (CFD) software was used to calculate the retinal wall wettability of a computational pseudophakic eye models using fluid analysis. The model utilized different gas volumes from 10 to 90%, in increments of 10% to the vitreous cavity in the supine, sitting, lateral, prone with closed eyes, and prone positions. Then, the gas cover rates of the retina were measured in each quadrant. When breaks are limited to the inferior retina anterior to the equator or multiple breaks are observed in two or more quadrants anterior to the equator, supine position maintained 100% gas cover rates in all breaks for the longest duration compared with other positions. When breaks are limited to either superior, nasal, or temporal retina, sitting, lower temporal, and lower nasal position were maintained at 100% gas cover rates for the longest duration, respectively. Our results may contribute to better surgical outcomes of RRDs and a reduction in the duration of the postoperative prone position.

scholarly journals Simulation of Hydraulic Cylinder Cushioning

2021 ◽  
Vol 13 (2) ◽  
pp. 494
Author(s):  
Antonio Algar ◽  
Javier Freire ◽  
Robert Castilla ◽  
Esteban Codina
Keyword(s):  
Dynamic Model ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Computational Fluid Dynamic Simulation ◽  
Hydraulic Cylinder ◽  
Outlet Port ◽  
Optimal Behavior ◽  
Radial Movement ◽  
Mechanical Shocks ◽  
Radial Gap

The internal cushioning systems of hydraulic linear actuators avoid mechanical shocks at the end of their stroke. The design where the piston with perimeter grooves regulates the flow by standing in front of the outlet port has been investigated. First, a bond graph dynamic model has been developed, including the flow throughout the internal cushion design, characterized in detail by computational fluid-dynamic simulation. Following this, the radial movement of the piston and the fluid-dynamic coefficients, experimentally validated, are integrated into the dynamic model. The registered radial movement is in coherence with the significant drag force estimated in the CFD simulation, generated by the flow through the grooves, where the laminar flow regime predominates. Ultimately, the model aims to predict the behavior of the cushioning during the movement of the arm of an excavator. The analytical model developed predicts the performance of the cushioning system, in coherence with empirical results. There is an optimal behavior, highly influenced by the mechanical stress conditions of the system, subject to a compromise between an increasing section of the grooves and an optimization of the radial gap.

CFD Simulation of a Co-rotating Twin-screw Extruder: Validation of a Rheological Model for a Starch-Based Dough for Snack Food

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Giorgia Tagliavini ◽  
Federico Solari ◽  
Roberto Montanari
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Second Phase ◽  
Snack Food ◽  
Suitable Model ◽  
Twin Screw Extruder ◽  
Parallel Plates ◽  
Screw Extruder ◽  
Twin Screw

AbstractThe extrusion of starch-based products has been a matter of interest, especially for the pasta and the snack food production. In recent years, twin-screw extruders for snack food have been studied from both structural and fluid dynamics viewpoints. This project started from the rheological characterization of a starch-based dough (corn 34 wt%, tapioca 32 wt%), comparing viscosity values acquired in laboratory with different theoretical models found in literature. A computational fluid dynamic (CFD) simulation recreating the simple case of a fluid flow between two parallel plates was carried out to validate the former comparison. After the rheological validation was completed, the second phase of this work covered a 3D CFD simulation of the first part of the twin-screw extruder (feeding zone). The objective was to find a suitable model for describing the dough rheological behavior and the operating conditions of a co-rotating intermeshing twin-screw extruder. Once the model would be defined, it would allow to investigate several working conditions and different screws geometries of the machine, predicting the evolution of the product rheological properties.

The Impact of Predried Lignite Cofiring With Hard Coal in an Industrial Scale Pulverized Coal Fired Boiler

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Halina Pawlak-Kruczek ◽  
Robert Lewtak ◽  
Zbigniew Plutecki ◽  
Marcin Baranowski ◽  
Michal Ostrycharczyk ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Bituminous Coal ◽  
Cfd Simulation ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Industrial Scale ◽  
Hard Coal ◽  
Cfd Simulations ◽  
Reference Case ◽  
The Impact

The paper presents the experimental and numerical study on the behavior and performance of an industrial scale boiler during combustion of pulverized bituminous coal with various shares of predried lignite. The experimental measurements were carried out on a boiler WP120 located in CHP, Opole, Poland. Tests on the boiler were performed during low load operation and the lignite share reached over to 36% by mass. The predried lignite, kept in dedicated separate bunkers, was mixed with bituminous coal just before the coal mills. Computational fluid dynamic (CFD) simulation of a cofiring scenario of lignite with hard coal was also performed. Site measurements have proven that cofiring of a predried lignite is not detrimental to the boiler in terms of its overall efficiency, when compared with a corresponding reference case, with 100% of hard coal. Experiments demonstrated an improvement in the grindability that can be achieved during co-milling of lignite and hard coal in the same mill, for both wet and dry lignite. Moreover, performed tests delivered empirical evidence of the potential of lignite to decrease NOx emissions during cofiring, for both wet and dry lignite. Results of efficiency calculations and temperature measurements in the combustion chamber confirmed the need to predry lignite before cofiring. Performed measurements of temperature distribution in the combustion chamber confirmed trend that could be seen in the results of CFD. CFD simulations were performed for predried lignite and demonstrated flow patterns in the combustion chamber of the boiler, which could prove useful in case of any further improvements in the firing system. CFD simulations reached satisfactory agreement with the site measurements in terms of the prediction of emissions.

Sign in / Sign up

Export Citation Format

Share Document