Experimental Investigation of Swirling Turbulent Jets PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Experimental Investigation of Swirling Turbulent Jets PDF full book. Access full book title Experimental Investigation of Swirling Turbulent Jets by Rahmat Taghavi. Download full books in PDF and EPUB format.
Author: Rahmat Taghavi
Publisher:
ISBN:
Category :
Languages : en
Pages : 350
Get Book Here
Book Description
Author: Rahmat Taghavi
Publisher:
ISBN:
Category :
Languages : en
Pages : 350
Get Book Here
Book Description
Author: Sara Toutiaei
Publisher:
ISBN: 9781321238839
Category : Jets
Languages : en
Pages : 52
Get Book Here
Book Description
In this study, velocity distributions of a swirling and a non-swirling jet flows were obtained using Laser Doppler Anemometer (LDA) in the near field where both jets are at the same stages of development. The resulting mean velocity and Reynolds stress distributions and the energy budgets of the axial Reynolds stresses are assessed. All Reynolds stresses showed higher magnitude in the swirling case compared to the non-swirling one at the same measurement axial locations. The swirling jet is found to exhibit larger production, mean convection and turbulence transport terms in the energy budget of axial Reynolds stress. The result shows faster development of the swirling jet compared with the non-swirling jet and is in consistency with previous studies. The turbulent transport term is found to be responsible for the faster development of the turbulence in the swirling jet.
Author: Jonathan Wayne Naughton
Publisher:
ISBN:
Category : Eddies
Languages : en
Pages : 30
Get Book Here
Book Description
Swirling jet flows have been studied experimentally and computationally and the results have been compared with theory. Three-component Laser Doppler Anemometry (LDA) measurements have been carried out for swirling jets of various strengths and swirl distributions. Radial profiles of velocity have been obtained from the jet exit to 50 diameters downstream. The experimental results are consistent with previous results and with similarity theory for weakly swirling turbulent jets. However, the parametric range and spatial domain of the current data set makes it suitable for validation. Computational simulations have also been performed using a combination of Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) approaches. The results have been validated with experimental data and used to explore the mechanisms behind the increased mixing enhancement observed. The combined experimental/computational effort is still ongoing, but the experiences to date have demonstrated the effectiveness of such an approach.
Author: Eric J. DeMillard
Publisher:
ISBN: 9781085621250
Category : Fluid dynamics
Languages : en
Pages : 56
Get Book Here
Book Description
Experimental investigations were carried out in both non-swirling and swirling jets at a Re = 105. A stereoscopic particle image velocimetry (SPIV) system was used to acquire the measurements in both axial-radial and radial-tangential planes at x/D = (1-10). Multiple test cases were taken where both the swirl magnitude and swirl distribution was adjusted. Proper Orthogonal Decomposition (POD) was then applied to the measurements to characterize turbulence structure. The results indicate that swirl causes the structure to be more ordered and shifts the relative amount of energy from axisymmetric structure to azimuthal structure.
Author: X. Hong-ging
Publisher:
ISBN:
Category :
Languages : en
Pages : 14
Get Book Here
Book Description
Author: Ing Kiet Francis Toh
Publisher:
ISBN:
Category : Jets
Languages : en
Pages : 247
Get Book Here
Book Description
The mean flow properties and the instantaneous flow structures of the jets are then investigated. The introduction and increase of swirl result in a higher jet growth, decay and turbulent intensity, the formation of an off-axis axial velocity maximum and the occurrence of vortex breakdown. The swirl-induced jet growth enhancement can be categorized into three regimes: a low swirl regime in which there is a limited enhancement, a moderate swirl regime in which the enhancement scales with swirl, and a high swirl regime in which vortex breakdown dominates the process. The jet growth behavior in the high swirl regime is found to be dependent on the structure of the jet and the vortex breakdown configuration. A significant change in the flow structures and certain mean flow properties including the centerline and local maximum axial velocity decay are observed in the low and the moderate swirl regimes. These properties appear to be less sensitive to swirl in the high swirl regime after the occurrence of vortex breakdown. The effects of Reynolds number on swirling jets may not be identical to that on a non-swirling jet. The statistical characteristics measured show that low velocity occasions in the vicinity of the jet centerline start to appear at a sufficiently high degree of swirl. These occasions increase with swirl until the eventual occurrence of vortex breakdown. The statistical characteristics of jets that have undergone vortex breakdown are very similar, as they are dominated by the vortex breakdown phenomenon. The mean flow and the statistical measurements also reveal the presence of an unstable vortex breakdown that is difficult to detect using flow visualization and instantanous velocity field measurements.
Author: Ronald M. C. So
Publisher:
ISBN:
Category : Combustion engineering
Languages : en
Pages : 164
Get Book Here
Book Description
Author: Ronald M. C. So
Publisher:
ISBN:
Category : Combustion engineering
Languages : en
Pages : 170
Get Book Here
Book Description
Author: Sean Clees
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Swirling jets are commonly used in combustion applications to stabilize flames and improve emissions. Thus, their dynamics play an important role in combustor design. Despite the prevalence of swirling flows in industrial applications that involve highly turbulent flow fields, the majority of experimental and numerical studies consider only laminar conditions. In this study, the dynamics of the vortex core are investigated in a swirling, turbulent jet at swirl numbers in the range of the critical swirl number for vortex breakdown. Vortex breakdown, a bifurcation in the structure of a swirling jet, results in the establishment of a stagnation point and recirculation region along the centerline of the jet. To study these dynamics, dynamic mode decomposition, an order-reduction technique used to extract coherent structures from flow data, is implemented. Investigation of time-averaged velocity fields and profiles leads to the identification of three flow regimes: pre-breakdown, near-breakdown, and post-breakdown. Velocity fields in these regimes are further analyzed using dynamic mode decomposition, Rankine-vortex fitting, and proper orthogonal decomposition to characterize jet dynamics with a particular focus on the development of the recirculation region characteristic of vortex breakdown. A precessing vortex core is also identified in the post-breakdown regime and its behavior is discussed.
Author: Nagalapadi Vengamaraja Pundarikanthan
Publisher:
ISBN:
Category :
Languages : en
Pages : 294
Get Book Here
Book Description
