scispace - formally typeset
Search or ask a question
Proceedings ArticleDOI

Application of Digital Image Processing Method for Spray Characterization

TL;DR: The basic tools of image processing are employed in this study to ease the computation of the required parameters in the estimation of fuel spray characteristics.
Abstract: From water sprinklers to combustion devices of launch vehicles, the applications of the liquid injectors are innumerable. Owing to the usage of non-renewable sources, there is a global movement towards improvement in the existing combustion systems. Efficiency and fuel emissions are influenced by fuel spray characteristics. One of the techniques used to capture the information on spray characteristics is highspeed shadowgraphy. Estimation of the required parameters needs analysis of image series. An automated method to replace tiring manual calculations makes it the job of a few seconds. The basic tools of image processing are employed in this study to ease the computation.
Citations
More filters
01 Apr 2001

77 citations

Journal ArticleDOI
TL;DR: In this article, a commercial pressure swirl injector is mounted in a swirl stabilized model gas turbine burner to investigate the spray characteristics with and without the presence of swirling flowfield under isothermal conditions.
Abstract: The effect of swirl flow on the spray characteristics (structure, droplet diameter and droplet velocity) is experimentally investigated for varying air-to-liquid momentum ratios in this work. The diagnostic techniques employed include high-speed shadowgraphy and 1D-PDPA. A commercial pressure swirl injector is mounted in a swirl stabilized model gas turbine burner to investigate the spray characteristics with and without the presence of swirling flowfield under isothermal conditions. In the absence of the injector flow the burner produced a converging-diverging flowfield at the burner exit, influenced by the bluffbody effect near to the exit and the swirling intensity farther downstream. The investigations reveal an unmistakable influence of the swirling flow on the droplet size, velocity and spatial distribution. Under the investigated momentum flux ratios the conical spray structure is altered and the droplets size and velocity at each location changed with the spatial variation in the magnitude and nature of the swirling flowfield. In general fine droplets are produced near to the high velocity air inflow, and coarser droplets in the recirculation zone owing to the longer residence time. The mean axial velocity of the droplet reduced in presence of swirling flow, with the droplets showing negative velocities at downstream locations.

3 citations


Cites methods from "Application of Digital Image Proces..."

  • ...An automated image processing procedure is followed to obtain instantaneous and time-averaged spray cone-angle, jet spread (Ls) and spray breakup lengths from the high-speed shadowgraph photos (Mohammed et al. 2019) (see Fig....

    [...]

References
More filters
Journal ArticleDOI
TL;DR: Based on two types of image models corrupted by impulse noise, two new algorithms for adaptive median filters are proposed that have variable window size for removal of impulses while preserving sharpness and are superior to standard median filters.
Abstract: Based on two types of image models corrupted by impulse noise, we propose two new algorithms for adaptive median filters. They have variable window size for removal of impulses while preserving sharpness. The first one, called the ranked-order based adaptive median filter (RAMF), is based on a test for the presence of impulses in the center pixel itself followed by a test for the presence of residual impulses in the median filter output. The second one, called the impulse size based adaptive median filter (SAMF), is based on the detection of the size of the impulse noise. It is shown that the RAMF is superior to the nonlinear mean L/sub p/ filter in removing positive and negative impulses while simultaneously preserving sharpness; the SAMF is superior to Lin's (1988) adaptive scheme because it is simpler with better performance in removing the high density impulsive noise as well as nonimpulsive noise and in preserving the fine details. Simulations on standard images confirm that these algorithms are superior to standard median filters. >

1,172 citations


"Application of Digital Image Proces..." refers methods in this paper

  • ...The other proposed methods for removal of salt and pepper noise are ranked-order based and impulse sized based adaptive median filters [15], a nonlinear anisotropic diffusion filter model [16] [17], a fuzzy mathematical morphology-based filter [18]....

    [...]

BookDOI
01 Jan 2006
TL;DR: In this paper, the authors compile these results into a series of chapters that address the various facets of the combustion instabilities in low-emission gas turbines and provide a valuable resource to help turbine users and manufacturers.
Abstract: Higher operating efficiencies, fewer pollutant emissions, and low capital investment have made gas turbines a dominant technology for a new power generating capacity in the US and worldwide. This book offers gas turbine users and manufacturers a valuable resource to help them sort through issues associated with combustion instabilities. In the last ten years, substantial efforts have been made in the industrial, governmental, and academic communities to understand the unique issues associated with combustion instabilities in low-emission gas turbines. The objective of this book is to compile these results into a series of chapters that address the various facets of the problem. The Case Studies section speaks to specific manufacturer and user experiences with combustion instabilities in the development stage and in fielded turbine engines. The book then goes on to examine The Fundamental Mechanisms, The Combustor Modeling, and Control Approaches.

902 citations


"Application of Digital Image Proces..." refers background in this paper

  • ...Combustion instability refers to the periodic oscillations of one or more natural acoustic modes of the combustor [21]....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the authors consider the relationship between size and pressure loss flow in the Annulus Flow through Liner Holes and describe the effect of Inlet Flow conditions on Inlet flow conditions.
Abstract: Basic Considerations Introduction Early Combustor Developments Basic Design Features Combustor Requirements Combustor Types Diffuser Primary Zone Intermediate Zone Dilution Zone Fuel Preparation Wall Cooling Combustors for Low Emissions Combustors for Small Engines Industrial Chambers Combustion Fundamentals Introduction Classification of Flames Physics or Chemistry? Flammability Limits Global Reaction-Rate Theory Laminar Premixed Flames Laminar Diffusion Flames Turbulent Premixed Flames Flame Propagation in Heterogeneous Mixtures of Fuel Drops, Fuel Vapor, and Air Droplet and Spray Evaporation Ignition Theory Spontaneous Ignition Flashback Stoichiometry Adiabatic Flame Temperature Diffusers Introduction Diffuser Geometry Flow Regimes Performance Criteria Performance Effect of Inlet Flow Conditions Design Considerations Numerical Simulations Aerodynamics Introduction Reference Quantities Pressure-Loss Parameters Relationship between Size and Pressure Loss Flow in the Annulus Flow through Liner Holes Jet Trajectories Jet Mixing Temperature Traverse Quality Dilution Zone Design Correlation of Pattern Factor Data Rig Testing for Pattern Factor Swirler Aerodynamics Axial Swirlers Radial Swirlers Flat Vanes versus Curved Vanes Combustion Performance Introduction Combustion Efficiency Reaction-Controlled Systems Mixing-Controlled Systems Evaporation-Controlled Systems Reaction- and Evaporation-Controlled Systems Flame Stabilization Bluff-Body Flameholders Mechanisms of Flame Stabilization Flame Stabilization in Combustion Chambers Ignition Assessment of Ignition Performance Spark Ignition Other Forms of Ignition Factors Influencing Ignition Performance The Ignition Process Methods of Improving Ignition Performance Fuel Injection Basic Processes in Atomization Classical Mechanism of Jet and Sheet Breakup Prompt Atomization Classical or Prompt? Drop-Size Distributions Atomizer Requirements Pressure Atomizers Rotary Atomizers Air-Assist Atomizers Airblast Atomizers Effervescent Atomizers Vaporizers Fuel Nozzle Coking Gas Injection Equations for Mean Drop Size SMD Equations for Pressure Atomizers SMD Equations for Twin-Fluid Atomizers SMD Equations for Prompt Atomization Internal Flow Characteristics Flow Number Discharge Coefficient Spray Cone Angle Radial Fuel Distribution Circumferential Fuel Distribution Combustion Noise Introduction Direct Combustion Noise Combustion Instabilities Control of Combustion Instabilities Modeling of Combustion Instabilities Heat Transfer Introduction Heat-Transfer Processes Internal Radiation External Radiation Internal Convection External Convection Calculation of Uncooled Liner Temperature Film Cooling Correlation of Film-Cooling Data Practical Applications of Transpiration Cooling Advanced Wall-Cooling Methods Augmented Cold-Side Convection Thermal Barrier Coatings Materials Liner Failure Modes Emissions Introduction Concerns Regulations Mechanisms of Pollutant Formation Pollutants Reduction in Conventional Combustors Pollutants Reduction by Control of Flame Temperature Dry Low-Oxides of Nitrogen Combustors Lean Premix Prevaporize Combustion Rich-Burn, Quick-Quench, Lean-Burn Combustor Catalytic Combustion Correlation and Modeling of Oxides of Nitrogen and Carbon Monoxide Emissions Concluding Remarks Alternative Fuels Introduction Types of Hydrocarbons Production of Liquid Fuels Fuel Properties Combustion Properties of Fuels Classification of Liquid Fuels Classification of Gaseous Fuels Alternative Fuels Synthetic Fuels Index References appear at the end of each chapter

610 citations


"Application of Digital Image Proces..." refers background in this paper

  • ...They have to be atomized into a large number of small droplets, to increase the surface area and hence, the evaporation rate [2]....

    [...]

Journal ArticleDOI
Xin Wang1
TL;DR: A model for making some edge detectors based on the Laplacian operator is introduced and the optimal threshold is introduced for obtaining a maximum a posteriori (MAP) estimate of edges
Abstract: Laplacian operator is a second derivative operator often used in edge detection. Compared with the first derivative-based edge detectors such as Sobel operator, the Laplacian operator may yield better results in edge localization. Unfortunately, the Laplacian operator is very sensitive to noise. In this paper, based on the Laplacian operator, a model is introduced for making some edge detectors. Also, the optimal threshold is introduced for obtaining a maximum a posteriori (MAP) estimate of edges

197 citations


"Application of Digital Image Proces..." refers methods in this paper

  • ...Prewitt, Laplacian of Gaussian, Canny, Sobel, Robert, LoG operator are a few of the most widely used edge detection techniques [6] [7]....

    [...]

01 Apr 2001

77 citations


"Application of Digital Image Proces..." refers methods in this paper

  • ...Prewitt, Laplacian of Gaussian, Canny, Sobel, Robert, LoG operator are a few of the most widely used edge detection techniques [6] [7]....

    [...]