Download or read book The Effects of Buoyancy on Turbulent Nonpremixed Jet Flames in Crossflow written by Isaac G. Boxx and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Amours historiques written by Eugène de Mirecourt and published by . This book was released on 1887 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploratory Study of the Effects of Buoyancy on Turbulent Non premixed Ethylene Jet Fames in Crossflow written by I. G. Boxx and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Manipulation and Control of Jets in Crossflow written by Ann R. Karagozian and published by Springer. This book was released on 2014-05-04 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamental Non-Reactive Jets in Crossflow and Other Jet Systems; Background on Modeling, Dynamical Systems, and Control; Reactive Jets in Crossflow and Multiphase Jets; Controlled Jets in Crossflow and Control via Jet Systems;
Download or read book Turbulent Jet Flames written by Kian Mehravaran and published by LAP Lambert Academic Publishing. This book was released on 2012-03 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the first part of this work, the impact of gravity on transitional and turbulent jet flames is investigated through Direct and Large Eddy Simulations (LES). It is shown that in the absence of gravity, combustion damps the flow instability; hence reduces "turbulence production" and jet growth. However, in the "finite-gravity" conditions, combustion generated density variations may promote turbulence and enhance both the mixing and combustion through buoyancy effects. In the second part, the LES/FMDF model is extended towards multi-step chemistry with realistic thermodynamic properties, such that the predictions could be compared with laboratory flame measurements. The consistency of the Eulerian and the Lagrangian solutions are discussed, and an efficient algorithm for parallelization of the hybrid code is presented. Comparisons with the Sandia's piloted methane jet flames (flame D and F) are performed and good agreements in the case of the near-equilibrium flame D have been achieved with a flamelet-based chemistry model, as well as with multi-step kinetics.
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 Modeling NO subscript X Emissions in Turbulent Jet Flames written by and published by . This book was released on 1994 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The effects of heat release on turbulent nonpremixed planar jet flames written by Jason Eric Rehm and published by . This book was released on 1999 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 41st AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2003 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Pressure and Fuel Structure on the Soot Yield of a Turbulent Diffusion Flame in a Crossflow written by Bruce Tobis and published by . This book was released on 1983 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solid Fuel Combustion in a Forced Turbulent Flat Plate Flow written by Liming Zhou and published by . This book was released on 199? with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study is conducted of the effect of flow velocity, grid-generated turbulence and buoyancy on the combustion of a solid fuel in a flat plate boundary layer flow. The effect of buoyancy is determined by comparing the surface regression rates, flame characteristics, and exhaust products composition for the solid burning in a flow and ceiling orientation. Measurements are presented for the ceiling surface regression rate of PMMA sheets burning in air, and compared with previously obtained floor data. It is concluded that buoyancy has two major, and counteracting, effects. One is to affect the heat transfer by shifting the flame away from the surface in the floor burning and closer to the surface in the ceiling. The other is also due to the flame shifting and the instabilities associated with it that favors, in the floor case, the mixing of the reactants, and consequently the overall heat release rate. In the ceiling, the proximity of the flame to the cold surface causes quenching of the reaction, and the stability of the flame hampers reactants mixing, both of which reduce the heat generation rate. The overall result of these two counteracting mechanisms is that the surface regression rates are not that different in both geometries, although the composition of the combustion products are quite different.
Download or read book The Entrainment and Mixing of a Round Buoyant Turbulent Jet in Crossflow written by David Charles Thoman and published by . This book was released on 1991 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Numerical Simulation of Turbulent Nonpremixed Reacting Flows with Buoyancy Effects written by Rongbin Zhong and published by . This book was released on 1999 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Buoyancy on the Flowfields of Lean Premixed Turbulentv flames written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Open laboratory turbulent flames used for investigating fundament flame turbulence interactions are greatly affected by buoyancy. Though much of our current knowledge is based on observations made in these open flames, the effects of buoyancy are usually not included in data interpretation, numerical analysis or theories. This inconsistency remains an obstacle to merging experimental observations and theoretical predictions. To better understanding the effects of buoyancy, our research focuses on steady lean premixed flames propagating in fully developed turbulence. We hypothesize that the most significant role of buoyancy forces on these flames is to influence their flowfields through a coupling with mean and fluctuating pressure fields. Changes in flow pattern alter the mean aerodynamic stretch and in turn affect turbulence fluctuation intensities both upstream and downstream of the flame zone. Consequently, flame stabilization, reaction rates, and turbulent flame processes are all affected. This coupling relates to the elliptical problem that emphasizes the importance of the upstream, wall and downstream boundary conditions in determining all aspects of flame propagation. Therefore, buoyancy has the same significance as other parameters such as flow configuration, flame geometry, means of flame stabilization, flame shape, enclosure size, mixture conditions, and flow conditions.
Download or read book Investigation of Acoustically Forced Non premixed Jet Flames in Crossflow written by Kevin Chek-Shing Marr and published by . This book was released on 2011 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented here discusses the effects of strong acoustic forcing on jet flames in crossflow (JFICF) and the physical mechanisms behind theses effects. For forced non-premixed JFICF, the jet fuel flow is modulated using an acoustic speaker system, which results in a drastic decrease in flame length and soot luminosity. Forced JFICF are characterized by periodic ejections of high-momentum, deeply penetrating vortical structures, which draws air into the jet nozzle and enhances mixing in the nearfield region of the jet. Mixture fraction images of the non-reacting forced jet in crossflow are obtained from acetone planar laser-induced fluorescence and show that the ejected jet fluid is effectively partially premixed. Flame luminosity images and exhaust gas measurements show that forced non-premixed JFICF exhibit similar characteristics to unforced partially-premixed JFICF. Both strong forcing and air dilution result in net reductions in NOx, but increases in CO and unburned hydrocarbons. NOx scaling analysis is presented for both forced non-premixed and unforced partially-premixed flames. Using flame volume arguments, EINOx scales with amplitude ratio for forced non- premixed flames, but does not scale with air dilution for unforced partially-premixed flames. The difference in scaling behavior is attributed to differences in flame structure. The effect of forcing on the flowfield dynamics of non-premixed JFICF is investigated using high-speed stereoscopic particle image velocimetry and luminosity imaging. The frequency spectra of the windward and lee-side flame base motions obtained from luminosity movies of the forced JFICF show a peak at the forcing frequency in the lee-side spectrum, but not on the windward-side spectrum. The lee-side flame base responds to the forcing frequency because the lee-side flame base stabilizes closer to the jet exit. The windward-side flame base does not respond to the forcing frequency because the integrated effect of the incident crossflow and vortical ejections leads to extinction of the flame base. From the PIV measurements, flowfield statistics are conditioned at the flame base. The local gas velocity at the flame base did not collapse for forced and unforced JFICF and was found to exceed 3SL. The flame propagation velocity was determined from the motion of the flame base, which is inferred from regions of evaporated seed particles in the time-resolved PIV images. The flame propagation velocity collapses for forced and unforced JFICF, which implies that the flame base is an edge flame; however, the most probable propagation velocity, approximately 2-3SL, is larger than propagation velocity predicted by edge flame theories. A possible explanation is that the flame propagation is enhanced by turbulent intensities and flame curvature.
Download or read book Effects of Non unity Lewis Number and Buoyancy in Hydrogen Jet Diffusion Flames written by Anil Kumar R. Shenoy and published by . This book was released on 1998 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 794 pages. Available in PDF, EPUB and Kindle. Book excerpt:
