Download or read book Numerical Investigation of Reacting Jet in crossflow at High Pressure written by Bernhard Stiehl and published by . This book was released on 2020 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simulated jet trajectories were in good agreement with the data and were described by an elliptic curvature to compensate for the poor far-field prediction of existing correlations. Non-premixed fuel-air condition in the axial fuel line resulted in an ignition point further downstream and reduced reaction rates. This delay can affect a NO benefit paired with relatively rich headend equivalence ratio, reducing the residence time of the reacting axial jet without exceeding spatial limitations. Dependencies of axial NO emission on the key influence parameters temperature, pressure and residence time were proposed.
Download or read book Numerical Investigation of Jets in a Reacting Crossflow written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigation of Jets in a Reacting Crossflow written by Hanan Urson and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mixing of air jets into hot, fuel-rich mixture is an integral part of many staged combustion applications. This study concentrates on the exhaust system of an electric arc steelmelting furnace where high concentrations of carbon monoxide (CO) and hydrogen (H2) are present. A three dimensional numerical code featuring two combustion models has been used to predict those emissions for various jet to cross-stream mass flow ratios and a comparison with experimental CO was done. The results showed that both models were unable to predict CO and H2 emissions for the conditions investigated. Thorough examination of the non-premixed flamelet revealed that the turbulent tune scale was much faster than the chemical time scale, thus, collapsing one of the requirements of this model. With the eddy dissipation model, the CO and H2 concentrations were severely underpredicted and convergence problem occurred when dissimilar chemical kinetic rates for CO and H 2 were incorporated.
Download or read book Effect of Jet Injection Angle and Number of Jets on Mixing and Emissions from a Reacting Crossflow at Atmospheric Pressure written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mixing of air jets into hot, fuel-rich products of a gas turbine primary zone is an important step in staged combustion. Often referred to as "quick quench," the mixing occurs with chemical conversion and substantial heat release. An experiment has been designed to simulate and study this process, and the effect of varying the entry angle (0 deg, 22.5 deg and 45 deg from normal) and number of the air jets (7, 9, and 11) into the main flow, while holding the jet-to-crossflow mass-low ratio, MR, and momentum-flux ratio, J, constant (MR = 2.5;J = 25). The geometry is a crossflow confined in a cylindrical duct with side-wall injection of jets issuing from orifices equally spaced around the perimeter. A specially designed reactor, operating on propane, presents a uniform mixture to a module containing air jet injection tubes that can be changed to vary orifice geometry. Species concentrations of O2, CO, CO2, NO(x) and HC were obtained one duct diameter upstream (in the rich zone), and primarily one duct radius downstream. From this information, penetration of the jet, the spatial extent of chemical reaction, mixing, and the optimum jet injection angle and number of jets can be deduced. St.John, D. and Samuelsen, G. S. Glenn Research Center NASA/CR-2000-209949, E-12202, NAS 1.26:209949
Download or read book An Experimental and Numerical Investigation of a Turbulent Round Jet Issuing Into an Unsteady Crossflow written by 夏麗萍 and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Dynamics of Fuel Jets Injected Into a High Temperature Subsonic Crossflow written by and published by . This book was released on 2015 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation of subsonic transverse jet injection into a subsonic vitiated crossflow is discussed. The reacting jet in crossflow (RJIC) system investigated as a means of secondary injection of fuel in a staged combustion system. The measurements were performed in test rigs featuring (a) a steady, swirling crossflow and (b) a crossflow with low swirl but significant oscillation in the pressure field and in the axial velocity. The rigs are referred to as the steady state rig and the instability rig. Rapid mixing and chemical reaction in the near field of the jet injection is desirable in this application. Temporally resolved velocity measurements within the wake of the reactive jets using 2D-PIV and OH-PLIF at a repetition rate of 5 kHz were performed on the RJIC flow field in a steady state water-cooled test rig. The reactive jets were injected through an extended nozzle into the crossflow which is located in the downstream of a low swirl burner (LSB) that produced the swirled, vitiated crossflow. Both H2/N2 and natural gas (NG)/air jets were investigated. OH-PLIF measurements along the jet trajectory show that the auto-ignition starts on the leeward side within the wake region of the jet flame. The measurements show that jet flame is stabilized in the wake of the jet and wake vortices play a significant role in this process. PIV and OH-PLIF measurements were performed at five measurement planes along the cross- section of the jet. The time resolved measurements provided significant information on the evolution of complex flow structures and highly transient features like, local extinction, re-ignition, vortex-flame interaction prevalent in a turbulent reacting flow. Nanosecond-laser-based, single-laser-shot coherent anti-Stokes Raman scattering (CARS) measurements of temperature and H2 concentraiton were also performed. The structure and dynamics of a reacting transverse jet injected into a vitiated oscillatory crossflow presents a unique opportunity for applying advanced experimental diagnostic techniques with increasing fidelity for the purposes of computational validation and model development. Numerical simulation of the reacting jet in crossflow is challenging because of the complex vortical structures in the flowfield and compounded by an unsteady crossflow. The resulting benchmark quality data set will include comprehensive, accurate measurements of mean and fluctuating components of velocity, pressure, and flame front location at high pressure and with crossflow conditions more representative of modern gas turbine engines. A proven means for producing combustion dynamics is used for the performing combustion instability experimental study on a reacting jet in crossflow configuration. The method used to provide an unsteady flowfield into which the transverse jet is injected is a unique and novel approach that permits elevated temperature and pressure conditions. A model dump combustor is used to generate and sustain an acoustically oscillating vitiated flow that serves as the crossflow for transverse jet injection studies. A fully optically accessible combustor test section affords full access surrounding the point of jet injection. High speed 10 kHz planar measurements OH PLIF and high frequency 180 kHz wall pressure measurements are performed on the injected reacting transverse jet and surrounding flowfield, respectively, under simulated unstable conditions. The overlay of the jet velocity flowfield and the flame front will be investigated using simultaneous 10 kHz OH PLIF and PIV in experiments to be performed in the near future.
Download or read book Flow Field and Mixing Characteristics of Multiple Reacting Jets in Vitiated Crossflow written by George M. Lapaan and published by . This book was released on 2014 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigation of Two Streamwise Turbulent Jets in a Crossflow written by Tedi G. Ohanian and published by . This book was released on 2002 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental and Numerical Investigation of a Turbulent Round Jet Issuing Into an Unsteady Crossflow written by Liping Xia and published by . This book was released on 1998 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigation of Variable Momentum Flux and Density Ratios on Confined Jets in Crossflow written by and published by . This book was released on 2016 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: A full unsteady Navier Stokes Equation (NSE) solver (known as the laminar model in FLUENT) is used to simulate a confined jet in crossflow (JICF) with Reynolds numbers (Re) in the range 287-2478. Reynolds Averaged Navier Stokes (RANS) equations are used to simulate JICF with Re in the range 4930-20000. Velocity ratios range between 0.84-3.15. Results of using the SST [lower case kappa] -- [lower case omega] or Realizable [lower case kappa] -- [lower case epsilon] are presented. Comparison to experimental data provided by the Air Force Research Lab shows that both the full NSE and RANS equations compare well with experimental data. The SST [lower case kappa] -- [lower case omega] predicts higher velocities than the Realizable model. The full Navier stokes simulation captures the major JICF vortical structures including the Counter-rotating Vortex Pair (CVP), upstream and downstream shear layers, horseshoe vortices, and hanging vortices. Many of these vortical details are lost in the RANS simulation. Two parametric studies on varying density ratio and momentum flux ratio are conducted. Varying density ratio is found to have little to no effect on the jet trajectory in the near-jet region. A lower density ratio leads to a higher Re which increases unsteadiness and turbulence which leads to improved mixing. Increasing momentum flux ratio generally increases jet penetration. However, a JICF with a larger boundary layer can penetrate deeper into the crossflow than a thinner boundary layer JICF even if the momentum flux ratio is smaller. Contributions of this work include providing additional simulation data for JICF at the presented flow conditions as well as validation of two RANS turbulence models and a full Navier Stokes solver.
Download or read book A Numerical Investigation of an Impinging Jet in a Crossflow written by Cesar Diaz and published by . This book was released on 1997 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical investigation of a jet impinging perpendicularly to a ground plane in the presence of crossflow was concluded using INCA, a finite-volume Navier-Stokes equations code.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Analysis of Turbulent Reacting Flows in Complex Combustion Systems written by Murat Yaldizli and published by . This book was released on 2009 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by John von Neumann-Institut für Computing and published by Forschungszentrum Jülich. This book was released on 2012 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigation of Slanted Slot Dilution Jet Mixing with a Cylindrical Crossflow written by Shane A. Moeykens and published by . This book was released on 1991 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigations of a Pipe Jet with Coil Insert Issuing Into a Crossflow written by Saul Guzman and published by . This book was released on 2015 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Numerical investigations of a jet in crossflow with two different coil inserts at four ratios of jet to the crossflow mean velocities were performed. The coils had a length to diameter (L/D) ratio of 2 and 11.25 and the velocity ratios, r, were 0.5, 1.0, 2.0, and 5.0. Results show when r=0.5, with coil inserts, jet penetration into the crossflow is reduced with increased entrainment near the jet outlet. Further results show that when r=2, and 5, near the jet outlet entrainments are reduced, with jet penetrating into higher elevations, before tilting in the direction of the crossflow. Comparing the results for the two coil inserts, with the shorter coil insert, higher penetration is obtained and with the longer coil, turbulent kinetic energy is increased in the near field.
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1994 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
