Download or read book Modeling of the Break up of Liquid Oxygen Droplets for Application in a Cryogenic Rocket Engine Simulation Code written by Emmanuel Bodele and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling Droplet Break up Effects for High pressure Cryogenic Spray Combustion Codes written by I. Gokalp and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sixth Annual Symposium written by NASA Propulsion Engineering Research Center. Symposium and published by . This book was released on 1994 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Statistical Modeling of the Air Blast Atomization in the Langrangian Computation of Liquid Spray written by M. Gorokhovski and published by . This book was released on 2001 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new sub-grid-scale stochastic model of drops air-blast breakup is presented in this paper. The stochastic process is considered in the framework of cascade of uncorrelated breakage events in series down to the critical size, independently from the initial distribution of sizes. To this end, the Kolmogorov's discrete model of particle breakup has been reproduced in the form of evolution equation for distribution function. The asymptotic solution of this equation has been applied to simulate the drop breakup alongside with Lagrangian model of spray dynamics. Performed computations of air-blast atomization are related to a spray close to the rocket engine configuration. A broad spectra of droplet size is simulated at each spray location with a co-existence of large drops and small droplets. The evolution of shape of the droplet-size pdF's is shown at different sections in downstream direction.
Download or read book Characteristics of Vaporizing Cryogenic Sprays for Rocket Combustion Modeling written by and published by . This book was released on 1994 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Computationally Inexpensive Method of Simulating Primary Droplet Breakup written by Brendon Cavainolo and published by . This book was released on 2020 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid droplet impingement on aircraft can be problematic as it leads to ice accretion. There have been many incidents of aircraft disasters involving ice accretion, such as American Eagle Flight 4184. Understanding liquid droplet impingement is critical in designing aircraft that can mitigate the damages caused by icing. However, the FAA’s regulations are only specified for “Appendix C” droplets; thus, aircraft designs may not be safe when accounting for droplets such as Supercooled Large Droplets. The assumptions of many models, such as the Taylor-Analogy Breakup (TAB) model, are no longer accurate for Supercooled Large Droplets, and the physics of those models break down. Computational modeling is used to simulate droplets in the SLD regime. A Lagrangian reference frame is used in this formulation. In this reference frame, a Volume of Fluid variation of the Navier-Stokes equations is used to resolve and isolate a single droplet. Experimental data shows conflicting results for Weber Number ranges in different primary breakup mechanisms. The goal of this research is to develop a computational model of a water droplet and test it against experimental data. This work shows that the scientific consensus on Weber Number ranges for different breakup modes may not necessarily be accurate, as the computational model agrees with some sets of experimental data but contradicts others.
Download or read book 31st AIAA ASME SAE ASEE Joint Propulsion Conference and Exhibit written by and published by . This book was released on 1995 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book COMPUTATIONAL METHODS FOR THE INVESTIGATION OF LIQUID DROP PHENOMENA IN EXTERNAL GAS FLOWS written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Computational methods for the investigation of drop deformation, drop breakup and drop solidification are developed and implemented in the open source computing environment OpenFOAM® [63]. The goal of this research is to simulate these drop phenomena by resolving all the relevant time and length scales in order to obtain correlations and statistical information which then can be used in the modeling of dispersed multiphase flows such as sprays. The use of such models is central for the simulation of dispersed multiphase flows because present-day computational technology does not have the capacity to resolve millions of droplets, as is typically encountered in sprays. There are three aspects to this thesis. Three types of simulations are performed. First, the two-phase flow solver, interFoam, is modified to allow for simulating a moving droplet in an external airflow within a fixed computational domain. The modified solver is then used for the modeling and simulation of deformation and breakup of drops in axisymmetric and three dimensional symmetric flows, and the results are utilized to validate drop deformation and breakup theories, and to derive statistical information for the product drop size distributions in the various flow regimes. The Taylor Analogy Breakup (TAB) model has been modified and this modified TAB model is also presented and validated. Second, the feasibility and accuracy of calculating convective heat transfer coefficients using CFD is studied for two test cases: the flow between parallel flat plates and the flow past a cylinder. The feasibility and accuracy is demonstrated and achieved by comparing the results with the literature. Third, for the investigation of the solidification of drops, an enhanced enthalpy- porosity model [6] is presented and implemented into OpenFOAM® to form a new solver, modPolyMeltFoam. Two test cases are used to validate the model and its implementation: the pure natural convection of water in a cavity and the solidification of water in a cavity. These tests show that the code performs very well comparing with results from the literature. The code is then coupled with the conjugate heat transfer solver, chtMultiRegionFoam, to create the solver modFluidFluidChtMultiRegionFoam which is able to simulate a stationary water droplet solidifying in a cold airflow. The results of the solidification studies are used to obtain correlations for the convective heat transfer coefficients, which in turn can be utilized in the modeling of freezing sprays where the solidification of millions of droplets needs to be described.
Download or read book Droplet Trajectory and Breakup Modeling with Comparisons to Previous Investigators Experimental Results for Slinger Atomizers written by Jayanth Malatkar and published by . This book was released on 2010 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Small Gas Turbine aircraft engine emerged in the 1940s as a distinct class of turbine engines. Following the late 1940s, the powerful, lightweight and reliable small gas turbine engine evolved as a major technology development leading to a new generation of aircraft, rotor craft and missiles. The compact size of the small gas turbine engine inhibits the use of the fuel injection systems used in conventional gas turbine engines. Hence an effective and efficient fuel injection system which is also simple in design was required to produce high-quality atomization of fuel in the small gas turbine engine. A centrifugal atomizer or rotary fuel slinger is designed to work on simple principles of engineering mechanics, while providing fine atomization of liquid. This research is an attempt to provide insight into the mechanism of atomization produced by fuel slingers and develop a mathematical model to predict the droplet trajectories, based on the elements of droplet breakup dynamics. The results of the model were further evaluated to test for compatibility with existing theories of atomization and thereby assess the applicability of the model to explain the complex mechanisms of liquid breakup from these atomizers. Mathematical expressions to predict the spatial and temporal positions of droplets were developed using appropriate relations for the coefficient of drag which accounted for the deformation of the droplets and reasonably accurate correspondence with experimentally visualized droplet trajectories has been observed. An analysis of the influence of hydrogen bonding in water, on the droplet breakup mechanism has also been made to account for the surface tension forces involved in atomization.
Download or read book 37th AIAA Aerospace Sciences Meeting and Exhibit written by and published by . This book was released on 1999 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Evaluation of Computational Methods to Model Large Droplet Secondary Breakup written by Jason Turner and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ice accretion on aircraft has been, and remains, a long-standing problem in the safe operation of flight vehicles. Ice can cause structural damage when ingested in engines and ruins the aerodynamic properties of lifting surfaces when it attaches to them. Ice accretion is typically simulated using a large scale model of an aircraft, or wing, with droplets treated as a dispersed phase. The dynamics of water droplets in the atmosphere are, thus, approximated with models. These models are tuned to match experimental data from in-flight and wind tunnel tests. Historically, icing from water droplets up to 50 micrometers in Mean Volumetric Diameter (MVD) has been considered. However, safety concerns have risen over the presence of droplets exceeding this size. Supercooled Large Droplets (SLD) are a class of droplets exceeding the 50-micrometer MVD limit. Increased droplet diameter complicates the physics of droplet deposition and breaks some of the assumptions enforced in models. This work attempts to provide a means of investigating the physics of an individual droplet, belonging to SLD regime, as it approaches a body in the most computationally efficient manner possible. A Galilean transformation is employed to isolate an individual droplet from a full model. Streamline data for this droplet is collected and then used as an input for an isolated droplet in a compact fluid domain. The droplet inside this domain is captured using a Volume of Fluid formulation of the Navier-Stokes equations. Early results suggest that assumptions of the stability of large droplets is not as certain as previous literature has suggested. This process can be used in any scenario where it is possible to capture a droplet streamline from an averaged data set.
Download or read book Handbook of Atomization and Sprays written by Nasser Ashgriz and published by Springer Science & Business Media. This book was released on 2011-02-18 with total page 922 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomization and sprays are used in a wide range of industries: mechanical, chemical, aerospace, and civil engineering; material science and metallurgy; food; pharmaceutical, forestry, environmental protection; medicine; agriculture; meteorology and others. Some specific applications are spray combustion in furnaces, gas turbines and rockets, spray drying and cooling, air conditioning, powdered metallurgy, spray painting and coating, inhalation therapy, and many others. The Handbook of Atomization and Sprays will bring together the fundamental and applied material from all fields into one comprehensive source. Subject areas included in the reference are droplets, theoretical models and numerical simulations, phase Doppler particle analysis, applications, devices and more.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 1596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Rocket Thrust Chambers written by Vigor Yang and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 2004 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first major publication on liquid-rocket combustion devices since 1960, and includes 20 chapters prepared by world-renowned experts. Each chapter focuses on a specific aspect of liquid-propellant combustion and thrust chamber dynamics, and is incorporated into the volume in a well-organized, cohesive manner. There are contributions from nine different countriesChina, France, Germany, Italy, Japan, the Netherlands, Russia, Sweden, and the United States.
Download or read book Liquid oxygen Droplet Vaporization and Combustion written by Jean-Pierre Delplanque and published by . This book was released on 1992 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt:
