Search results for "cfd"

Investigation of Flow and Heat Transfer in Corrugated-Undulated Plate Heat Exchangers

2000

An experimental and numerical investigation of heat transfer and fluid flow was conducted for corrugated-undulated plate heat exchanger configurations under transitional and weakly turbulent conditions. For a given geometry of the corrugated plates the geometrical characteristics of the undulated plates, the angle formed by the latter with the main flow direction, and the Reynolds number were made to vary. Distributions of the local heat transfer coefficient were obtained by using liquid-crystal thermography, and surface-averaged values were computed; friction coefficients were measured by wall pressure tappings. Overall heat transfer and pressure drop correlations were derived. Three-dimen…

MHD free convection in a liquid-metal filled cubic enclosure. I. Differential heating

2002

On natural convection in a single and two zone rectangular enclosure

1992

Abstract Convective heat transfer was investigated numerically for rectangular enclosures both undivided and divided in two zones by a vertical partition, and having opposite isothermal walls at different temperatures. The aspect ratio was varied from 0.1 to 16 and the Rayleigh number from 3.5 ∗ 10 3 to ∗ 10 7 (non-partitioned enclosures) and from 1.0 ∗ 10 5 to 1.6 ∗ 10 8 (partitioned enclosures). The thickness and conductivity of the partition were varied. The end wall thermal boundary conditions were adiabatic or LTP (Linear Temperature Profile). The continuity, momentum and energy equations for a 2-D laminar steady flow were solved under the Boussinesq approximation by using a finite-dif…

Computerized dynamic fluid simulation (CFD) for measuring the influence of the cab deflector on the aerodynamics of trucks

2021

This paper refers to how the cab deflector of trucks can influence the aerodynamic coefficient. The first part of the paper includes some generalities taken from previous studies, regarding the types of solutions to improve aerodynamics for trucks. The second part of the paper is a more practical one and has two main chapters: modeling and simulation of modeled parts. In this sense, a truck and 3 cabin deflectors were schematically modeled in Catia v5. After assembly in the Catia v5 program, the impact of the cabin deflector was analyzed. Thus, a computerized dynamic fluid simulation (CFD) was performed using the specific module in Ansys. The simulation included the CFD analysis of the four…

Turbulent Fluid Flow in Closed- and Free-Surface Unbaffled Tanks Stirred by Radial Impellers

1996

Liberty winter gardens in Palermo: contamination from solar design

2020

At the end of the 19th century, the city of Palermo boasted a tradition of steel elements that could include the most beautiful railings and light steel structures of the time. The paper shows how the technological, formal and spatial aspects of the metallic construction was derived by the application of Central Europe areas examples to the local reality, providing notions on designs, experimentations and originalities. Canopies, verandas, winter gardens and orangeries are architectural elements in iron and glass that represent an added value for the building, they improve the life quality of the people who live there. In particular, in the Liberty architecture these elements took shape thr…

Numerical simulation of transcatheter mitral valve replacement: The dynamic implication of LVOT obstruction in the valve-in-ring case.

2022

Transcatheter mitral valve replacement (TMVR) has been used for “off-label” treatment when annuloplasty band ring for mitral repair fails. However, the complex anatomy and function of the mitral valve may lead to fatal complications as a result of the left ventricular outflow tract (LVOT) obstruction in TMVR. We report the structural and hemodynamic response of LVOT obstruction resulting from TMVR with the Edwards SAPIEN 3 Ultra (S3) device. We modified the original Living Heart Human Model (LHHM) to account for a failed mitral valve with an annuloplasty band ring and simulated the cardiac beating condition in the setting of S3 device implantation. Findings demonstrated a high dynamic behav…

Unsteadiness and transition to turbulence in woven spacer filled channels for Membrane Distillation

2017

To characterize the performance of Membrane Distillation (MD) modules, channels filled with woven spacers were investigated by Computational Fluid Dynamics (including Direct Numerical Simulations and the use of the SST k-ω turbulence model) and by parallel experiments with Thermochromic Liquid Crystals. The cases considered here regard mutually orthogonal filaments with a spacer pitch to channel height ratio P/H=2, two spacer orientations θ with respect to the main flow (0° and 45°), and bulk Reynolds numbers Re from ∼200 to ∼2000, an interval of great interest in practical MD applications. For both values of θ, CFD predicted steady-state flow for Re up to ∼300, and chaotic flow …

New relations between professional and work’s organizations introduced by computer applications, special vessel case study

2019

At present time the project of a naval vehicle, where with the word project we refer to all the process of design and manufacturing, especially when the vehicle offers special formal and performance characteristics, involves a number of operators that has been increasing considerably in recent decades, and this increased complexity can be correlated with dimensional and typological growth of many categories of ships. Simultaneously we are witnessing a complete new project approach, where the possibility given by the computer contribution to represent processes and results becomes crucial. The paper aims to investigate the consequences of this progress in the organization of the project and …

Large-Eddy Simulation e tecnica LS-PIV: lo studio della turbolenza superficiale

2021

Gli avanzamenti tecnologici degli ultimi decenni hanno fatto registrare la rapida diffusione di tecnologie innovative con cui condurre un monitoraggio ambientale più efficiente ed efficace. Nel campo del monitoraggio fluviale sono sempre più utilizzate le tecniche basate sull’elaborazione di immagini, fornendo una valida alternativa alle metodologie tradizionalmente adottate. Le tecniche ottiche restituiscono infatti misure non intrusive, assicurando migliori condizioni di sicurezza per gli operatori. I metodi ottici più utilizzati sono la Large-Scale Particle Image Velocimetry (LS-PIV) [1] e la Large-Scale Particle Tracking Velocimetry (LS-PTV) [2]. Le tecniche LS-PIV e LS-PTV si basano su…