Library Subscription: Guest
ICHMT DL Home Current Year Archives Executive Committee International Centre for Heat and Mass Transfer

NUMERICAL SOLUTION OF THERMAL BUOYANT FLOW WITH HIGHER ORDER LAGRANGIAN BLOBS METHOD

DOI: 10.1615/ICHMT.2008.CHT.360
22 pages

Carmine Golia
Department of Aerospace and Mechanical Engineering, Faculty of Engineering, Second University of Naples, via Roma 29, 81031 Aversa, Italy

Bernardo Buonomo
Dipartimento di Ingegneria Industriale e dell'Informazione, Università degli Studi della Campania "Luigi Vanvitelli," Aversa (CE), Italy

Antonio Viviani
Seconda Università di Napoli

Abstract

To improve the accuracy of both the integral approximation of differential operators (Divergence, Gradient and Laplacian) and of the regrid process, in the simulation of 3D thermal buoyant flows with meshless Lagrangian Blobs methods, the authors developed an integral discretization of the differential operators of the field equations, by using convolutions of truncated 3D-Taylor series expansions of field functions with a kernel defined on a compact domain around the blob centre of a given particle (Taylor Convolution Complete: TCC). This method allows to overtake the irregular distribution of cells in the compact domain around the given blob, the deficiency of cells in the compact support due to the presence of a boundaries cutting the compact support of nearby blobs, and allows to delay the use of regrid process to smooth the blob spatial distribution. The main scope of the present work is to explore new higher order kernels capable to give an accuracy larger than the classical one [O(h2)]. They propose a new polynomial kernel that is used within TCC to compute Gradients, Laplacian terms and for regrid processes. This new formulation, that is [O(h3)], is verified by solving a plume thermal buoyant problem, at realistic values of the Grashof number [O(1010)], and compared with the same problem solved with classical kernel. The use of new kernel gives much better results: larger rising of the plume and better time trends of the control parameter than are within 2 orders of magnitude smaller. Due to the better accuracy and details, the time trend of the global zeroth order vorticity Moment presents two spikes that are investigated in details. The first event is found to correspond to a pinch-off phenomenon between stem and cap of the trailing buoyant mushroom and is verified at a non-dimensional time that falls within the interval limit stated by theoretical and experimental findings available in the literature. The second event is also dependent by secondary pinch-off phenomenon that is verified within the mushroom cap, but up to now relating experimental evidences are not available in the literature.

ICHMT Digital Library

Bow shocks on a jet-like solid body shape. Thermal Sciences 2004, 2004. Pulsed, supersonic fuel jets - their characteristics and potential for improved diesel engine injection. PULSED, SUPERSONIC FUEL JETS - THEIR CHARACTERISTICS AND POTENTIAL FOR IMPROVED DIESEL ENGINE INJECTION
View of engine compartment components (left). Plots of temperature distributions in centreplane, forward of engine (right). CHT-04 - Advances in Computational Heat Transfer III, 2004. Devel... DEVELOPMENT AND CURRENT STATUS OF INDUSTRIAL THERMOFLUIDS CFD ANALYSIS
Pratt & Whitney's F-135 Joint Strike Fighter Engine under test in Florida is a 3600F class jet engine. TURBINE-09, 2009. Turbine airfoil leading edge stagnation aerodynamics and heat transfe... TURBINE AIRFOIL LEADING EDGE STAGNATION AERODYNAMICS AND HEAT TRANSFER - A REVIEW
Refractive index reconstructed field. (a) Second iteration. (b) Fourth iteration. Radiative Transfer - VI, 2010. Theoretical development for refractive index reconstruction from a radiative ... THEORETICAL DEVELOPMENT FOR REFRACTIVE INDEX RECONSTRUCTION FROM A RADIATIVE TRANSFER EQUATION-BASED ALGORITHM
Two inclusion test, four collimated sources. Radiative Transfer - VI, 2010. New developments in frequency domain optical tomography. Part II. Application with a L-BFGS associated to an inexa... NEW DEVELOPMENTS IN FREQUENCY DOMAIN OPTICAL TOMOGRAPHY. PART II. APPLICATION WITH A L-BFGS ASSOCIATED TO AN INEXACT LINE SEARCH