Home eBooks Download › numerical simulations of a developing turbulent wall jet along a thermally active surface

Numerical Simulations Of A Developing Turbulent Wall Jet Along A Thermally Active Surface

Download Numerical Simulations Of A Developing Turbulent Wall Jet Along A Thermally Active Surface PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Numerical Simulations Of A Developing Turbulent Wall Jet Along A Thermally Active Surface book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page

Numerical Simulations Of A Developing Turbulent Wall Jet Along A Thermally Active Surface

DOWNLOAD
Author : Qingtian Wang
language : en
Publisher:
Release Date : 1999

Numerical Simulations Of A Developing Turbulent Wall Jet Along A Thermally Active Surface written by Qingtian Wang and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1999 with Air ducts categories.

Temporal Numerical Simulations Of Turbulent Coanda Wall Jets

DOWNLOAD
Author : Pietro Valsecchi
language : en
Publisher:
Release Date : 2006

Temporal Numerical Simulations Of Turbulent Coanda Wall Jets written by Pietro Valsecchi and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006 with categories.

In a novel application of the temporal numerical simulation, an investigation ofturbulence modeling techniques is carried for the turbulent wall jet over aconvex surface (Coanda wall jet.) The simultaneous presence of multipleinstability mechanisms and the interaction with the turbulence dynamics at thesolid boundary produces a unique combination of different large turbulentcoherent structures that constitutes both a consistent challenge for numericalsimulations and an ideal test bed for turbulence models. The Temporal Direct Numerical Simulation (TDNS) of the Coanda wall jetrestricts the focus from the global turbulent Coanda wall jet to a smaller, localportion of the flow and offers a wide array of advantages to the present work. Inparticular, the size of the computational domain can be arbitrarily chosen inboth the spanwise and the streamwise directions. This allows to either suppressor enhance individual physical mechanisms and, consequently, to selectivelyreproduce different large coherent structures within the local flow. In the firstpart, temporal numerical simulations are employed to reproduce four differentflow scenarios of the local Coanda wall jet with a level of numerical resolutionthat, because of the reduced size of the computational domain, cannot be matchedby standard DNS of the entire physical flow (spatial DNS, or SDNS.)The TDNS of these four flow scenarios are then used in the second part for ana--posteriori analysis of different turbulence models in order to addresscommon shortcomings shown by Hybrid Turbulence Models (HTM). For each flowscenario, the turbulent flow field is deliberately decomposed in resolved andunresolved flows by the application of different filters in space correspondingto different grid resolution. The behavior of turbulence models can be reproducedfrom the resolved flow and compared to theturbulent stress tensor directlycalculated from the unresolved part of the flow field. Starting from the RANSlimit, turbulence models with different levels of complexity are studied. Successively, the performance of these models is analyzed at intermediatenumerical resolutions between RANS, LES, and DNS. Finally, an improvedformulation of the Flow Simulation Methodology (FSM) is proposed.

Numerical Simulations Of Wall Jets

DOWNLOAD
Author :
language : en
Publisher:
Release Date : 1997

Numerical Simulations Of Wall Jets written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1997 with categories.

This document summarizes the three year investigation of transitional and turbulent wall jets using direct numerical simulation (DNS) and large eddy simulation (LES). Towards this end, a three-dimensional, incompressible Navier-Stokes code developed in our research group for DNS of boundary-layer transition was adapted to the wall jet geometry. The code is based on the spatial model and is fourth-order accurate. For the LES, a Smagorinsky based subgrid-scale turbulence model and explicit fourth-order accurate compact filtering were incorporated. As an initial condition, a base flow close to Glauert's similarity solution of the laminar wall jet was employed. This flow was forced by blowing and suction through a slot in the wall. Periodic forcing was used for investigating primary and secondary instabilities in transitional wall jets (Re=2OO) We discovered competing two-dimensional (2-D) and three-dimensional (3-D) instability mechanisms which can be influenced significantly by the type of forcing. 2-D large/amplitude forcing produces (2-D) large coherent structures which reduce wall shear but may lead to ejections of vortices from the wall and even to a detachment of the wall jet. Additional 3-D forcing weakens these coherent structures (especially in the near-wall region) and can thus prevent vortex ejections. In our LES of turbulent wall jets, rapid breakdown to turbulence was triggered by large/amplitude 3-D random forcing. Despite the purely 3-D forcing, 2-D coherent structures still emerge in the free shear layer-like outer region, an indication of the strong 2-D instability of the wall jet. A fully turbulent mean flow which compares well with experiments is obtained for higher Reynolds numbers (Re=2OOO).

Computational Study Of Heat And Mass Transfer With Phase Change Condensation And Evaporation In A Developing Two Dimensional Wall Jet Velocity And Temperature Fields

DOWNLOAD
Author : R. Arman Dwiartono
language : en
Publisher:
Release Date : 2004

Computational Study Of Heat And Mass Transfer With Phase Change Condensation And Evaporation In A Developing Two Dimensional Wall Jet Velocity And Temperature Fields written by R. Arman Dwiartono and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2004 with Condensation categories.