scholarly journals Numerical predictions and experimental results of air flow in a smooth quarter-scale nacelle

2002 ◽  
Author(s):  
A. Black ◽  
J. Suo-Anttila ◽  
P. Disimile ◽  
J. Tucker
Keyword(s):  
Air Flow ◽  
Experimental Results ◽  
Numerical Predictions

scholarly journals Numerical Predictions and Experimental Results of Air Flow in a Smooth Quarter-Scale Nacelle

2002 ◽  
Author(s):  
AMALIA R BLACK ◽  
JILL M SUO-ANTTILA ◽  
LOUIS A GRITZO ◽  
PETER J DISIMILE ◽  
JAMES R TUCKER
Keyword(s):  
Air Flow ◽  
Experimental Results ◽  
Numerical Predictions

Numerical investigation of the propagation of shock waves in rigid porous materials: development of the computer code and comparison with experimental results

1996 ◽  
Vol 324 ◽  
pp. 163-179 ◽  
Author(s):  
A. Levy ◽  
G. Ben-Dor ◽  
S. Sorek
Keyword(s):  
Porous Materials ◽  
Initial Conditions ◽  
Computer Code ◽  
Experimental Results ◽  
Numerical Code ◽  
Materials Development ◽  
Numerical Predictions ◽  
Wide Range ◽  
Dimensional Version ◽  
The One

The governing equations of the flow field which is obtained when a thermoelastic rigid porous medium is struck head-one by a shock wave are developed using the multiphase approach. The one-dimensional version of these equations is solved numerically using a TVD-based numerical code. The numerical predictions are compared to experimental results and good to excellent agreements are obtained for different porous materials and a wide range of initial conditions.

The Simulation of Natural Ventilation of Buildings With Different Location of Windows/Openings

2015 ◽  
Author(s):  
A. Idris ◽  
B. P. Huynh ◽  
Z. Abdullah
Keyword(s):  
Air Quality ◽  
Flow Pattern ◽  
Turbulence Model ◽  
Natural Ventilation ◽  
Air Flow ◽  
Building Design ◽  
Building Envelope ◽  
Navier Stokes ◽  
Computational Domain ◽  
Numerical Predictions

Ventilation is a process of changing air in an enclosed space. Air should continuously be withdrawn and replaced by fresh air from a clean external source to maintain internal good air quality, which may referred to air quality within and around the building structures. In natural ventilation the air flow is due through cracks in the building envelope or purposely installed openings. Its can save significant amount of fossil fuel based energy by reducing the needs for mechanical ventilation and air conditioning. Numerical predictions of air velocities and the flow patterns inside the building are determined. To achieve optimum efficiency of natural ventilation, the building design should start from the climatic conditions and orography of the construction to ensure the building permeability to the outside airflow to absorb heat from indoors to reduce temperatures. Effective ventilation in a building will affects the occupant health and productivity. In this work, computational simulation is performed on a real-sized box-room with dimensions 5 m × 5 m × 5 m. Single-sided ventilation is considered whereby openings are located only on the same wall. Two opening of the total area 4 m2 are differently arranged, resulting in 16 configurations to be investigated. A logarithmic wind profile upwind of the building is employed. A commercial Computational Fluid Dynamics (CFD) software package CFD-ACE of ESI group is used. A Reynolds Average Navier Stokes (RANS) turbulence model & LES turbulence model are used to predict the air’s flow rate and air flow pattern. The governing equations for large eddy motion were obtained by filtering the Navier-Stokes and continuity equations. The computational domain was constructed had a height of 4H, width of 9H and length of 13H (H=5m), sufficiently large to avoid disturbance of air flow around the building. From the overall results, the lowest and the highest ventilation rates were obtained with windward opening and leeward opening respectively. The location and arrangement of opening affects ventilation and air flow pattern.

Numerical predictions of the flow characteristics of subsonic jet emanating from corrugated lobed nozzle

2020 ◽  
Vol 92 (7) ◽  
pp. 955-972
Author(s):  
Roy V. Paul ◽  
Kriparaj K.G. ◽  
Tide P.S.
Keyword(s):  
Flow Characteristics ◽  
Experimental Results ◽  
Potential Core ◽  
Content Type ◽  
Numerical Predictions ◽  
Core Length ◽  
Chevron Nozzle ◽  
Centreline Velocity ◽  
Subsonic Jet ◽  
Lobed Nozzle

Purpose The purpose of this study is to investigate the aerodynamic characteristics of subsonic jet emanating from corrugated lobed nozzle. Design/methodology/approach Numerical simulations of subsonic turbulent jets from corrugated lobed nozzles using shear stress transport k-ω turbulence model have been carried out. The analysis was carried out by varying parameters such as lobe length, lobe penetration and lobe count at a Mach number of 0.75. The numerical predictions of axial and radial variation of the mean axial velocity, u′u′ ¯ and v′v′ ¯ have been compared with experimental results of conventional round and chevron nozzles reported in the literature. Findings The centreline velocity at the exit of the corrugated lobed nozzle was found to be lower than the velocity at the outer edges of the nozzle. The predicted potential core length is lesser than the experimental results of the conventional round nozzle and hence the decay in centreline velocity is faster. The centreline velocity increases with the increase in lobe length and becomes more uniform at the exit. The potential core length increases with the increase in lobe count and decreases with the increase in lobe penetration. The turbulent kinetic energy region is narrower with early appearance of a stronger peak for higher lobe penetration. The centreline velocity degrades much faster in the corrugated nozzle than the chevron nozzle and the peak value of Reynolds stress appears in the vicinity of the nozzle exit. Practical implications The corrugated lobed nozzles are used for enhancing mixing without the thrust penalty inducing better acoustic benefits. Originality/value The prominent features of the corrugated lobed nozzle were obtained from the extensive study of variation of flow characteristics for different lobe parameters after making comparison with round and chevron nozzle, which paved the way to the utilization of these nozzles for various applications.

A Duct Optimization Study for a Vertical Axis Hydro-current Turbine Model

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
M. Alidadi ◽  
V. Klaptocz ◽  
G. W. Rawlings ◽  
Y. Nabavi ◽  
S. Calisal
Keyword(s):  
Power Output ◽  
Numerical Optimization ◽  
Vertical Axis ◽  
Experimental Results ◽  
Maximum Power Output ◽  
Numerical Predictions ◽  
Optimization Study ◽  
Current Turbine ◽  
Turbine Model ◽  
Good Agreement

A numerical optimization study is used to design a duct for a model of vertical axis hydro-current turbine. The effects of this duct on the power output and torque fluctuations of the turbine model are then examined numerically and experimentally. Relatively good agreement was obtained between the experimental results and numerical predictions especially at higher tip speed ratios. Experimental results show an 85% increase in the maximum power output when the turbine is placed inside the duct. The numerical and experimental torque curves for the turbine also show substantial reductions in the torque fluctuations as a result of ducting.

scholarly journals A Study on Double Concentric Jets : 1st Report, Experimental Results of Air-Air Flow

1972 ◽  
Vol 38 (311) ◽  
pp. 1753-1762
Author(s):  
Ryuichi MATSUMOTO ◽  
Kyoji KIMOTO ◽  
Nobutaka TSUCHIMOTO
Keyword(s):  
Air Flow ◽  
Experimental Results

Application of an Object-Oriented CFD Code to Heat Transfer Analysis

2008 ◽  
Author(s):  
Luca Mangani ◽  
A. Andreini
Keyword(s):  
Heat Transfer ◽  
Turbulence Models ◽  
Lateral Spreading ◽  
Impinging Jets ◽  
Experimental Results ◽  
Heat Transfer Analysis ◽  
Specific Class ◽  
Turbine Cooling ◽  
Numerical Predictions ◽  
High Flexibility

This paper is aimed at showing the performances obtained with an open-source CFD code for heat transfer predictions after the addiction of specific modules. The development steps to make this code suitable for such simulations are described in order to point out its potentiality as a customizable CFD tool, appropriate for both academic and industrial research. The C++ library, named OpenFOAM, offers specific class and polyhedral finite volume operators thought for continuum mechanics simulations as well as built-in solvers and utilities. To make it robust, fast and reliable for RANS heat transfer predictions it was indeed necessary to implement additional submodules. The package coded by the authors within the OpenFOAM environment includes a suitable algorithm for compressible steady-state analysis. A SIMPLE like algorithm was specifically developed to extend the operability field to a wider range of Mach numbers. A set of Low-Reynolds eddy-viscosity turbulence models, chosen amongst the best performing in wall bounded flows, were developed. In addition an algebraic anisotropic correction, to increase jets lateral spreading, and an automatic wall treatment, to obtain mesh independence, were added. The results presented cover several types of flows amongst the most typical for turbomachinery and combustor gas turbine cooling devices. Impinging jets were investigated as well as film and effusion cooling flows, both in single and multi-hole configuration. Numerical predictions for wall effectiveness and wall heat transfer coefficient were tested against standard literature and in-house set-up experimental results. The numerical predictions obtained proves to be in-line with the equivalent models of commercial CFD packages obtaining a general good agreement with the experimental results. Moreover during the tests OpenFOAM code has shown a good accuracy and robustness, as well as an high flexibility in the implementation of user-defined submodules.

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