Experimental Validation Benchmark Data for Computational Fluid Dynamics of Mixed Convection on a Vertical Flat Plate

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Blake W. Lance ◽  
Jeff R. Harris ◽  
Barton L. Smith
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Mixed Convection ◽  
Turbulent Flows ◽  
Velocity Profiles ◽  
Heated Wall ◽  
Validation Data ◽  
Cfd Models ◽  
Fluid Properties ◽  
High Level

Model validation for computational fluid dynamics (CFD), where experimental data and model outputs are compared, is a key tool for assessing model uncertainty. In this work, mixed convection was studied experimentally for the purpose of providing validation data for CFD models with a high level of completeness. Experiments were performed in a facility built specifically for validation with a vertical, flat, heated wall. Data were acquired for both buoyancy-aided and buoyancy-opposed turbulent flows. Measured boundary conditions (BCs) include as-built geometry, inflow mean and fluctuating velocity profiles, and inflow and wall temperatures. Additionally, room air temperature, pressure, and relative humidity were measured to provide fluid properties. Measured system responses inside the flow domain include mean and fluctuating velocity profiles, temperature profiles, wall heat flux, and wall shear stress. All of these data are described in detail and provided in tabulated format.

scholarly journals Experimental Validation Benchmark Data for Computational Fluid Dynamics of Transient Convection From Forced to Natural With Flow Reversal on a Vertical Flat Plate

2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Blake W. Lance ◽  
Barton L. Smith
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Velocity Profiles ◽  
Flow Reversal ◽  
System Response ◽  
Heated Plate ◽  
Cfd Validation ◽  
Validation Data ◽  
Benchmark Data ◽  
Extra Effort

Transient convection has been investigated experimentally for the purpose of providing computational fluid dynamics (CFD) validation benchmark data. A specialized facility for validation benchmark experiments called the rotatable buoyancy tunnel (RoBuT) was used to acquire thermal and velocity measurements of flow over a smooth, vertical heated plate in air. The initial condition was forced convection downward with subsequent transition to mixed convection, ending with natural convection upward after a flow reversal. Data acquisition through the transient was repeated for ensemble-averaged results. With simple flow geometry, validation data were acquired at the benchmark level. All boundary conditions (BCs) were measured and their uncertainties quantified. Temperature profiles on all the four walls and the inlet were measured, as well as as-built test section geometry. Inlet velocity profiles and turbulence levels were quantified using particle image velocimetry (PIV). System response quantities (SRQs) were measured for comparison with CFD outputs and include velocity profiles, wall heat flux, and wall shear stress. Extra effort was invested in documenting and preserving the validation data. Details about the experimental facility, instrumentation, experimental procedure, materials, BCs, and SRQs are made available through this paper. The latter two are available for download while other details are included in this work.

Validation Study on Forced and Mixed Convection in the Rotatable Buoyancy Tunnel

2013 ◽  
Author(s):  
Blake W. Lance ◽  
Jeff R. Harris ◽  
Jared M. Iverson ◽  
Robert E. Spall ◽  
Richard W. Johnson ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Mixed Convection ◽  
Test Section ◽  
Fluid Velocity ◽  
Heated Wall ◽  
Data Sets ◽  
Heated Plate ◽  
Validation Data ◽  
Opposed Flow ◽  
High Level

The Rotatable Buoyancy Tunnel (RoBuT) at Utah State University, built for validation measurements incorporating a high level of data completeness, is described along with the results from validation data sets for forced and mixed convection. One wall of the tunnel test section is heated while the other three are transparent for optical access. All boundary conditions, including geometry, wall temperature and inflow temperature and velocity, are measured and their uncertainties are reported. The tunnel’s design is unique in that the test section can be inverted by rotating the entire facility to generate mixed convection with either buoyancy aided or buoyancy opposed flow. The RoBuT can also produce forced or natural convection, either steady or transient. Measurements for forced and buoyancy-aided mixed convection over a vertical heated plate are described. The RoBuT allows for simultaneous measurements of velocity, wall and inlet air temperature, heat flux measurements on the heated wall, and pressure drop across the test section. The fluid velocity is measured by time-averaged particle image velocimetry (PIV). The first validation case is forced convection since this flow is well understood. Both forced and mixed convection results are compared to published correlations and computational fluid dynamics (CFD) studies. The CFD is steady and 3-D using as-built measurements of the geometry. Experimental wall and inlet temperatures are used for CFD boundary conditions, as well as the inlet velocity and turbulence profiles. Three research groups perform simulations with varying levels of knowledge of the experimental results.

scholarly journals A Feasible Computational Fluid Dynamics Study for Relationships of Structural and Functional Alterations with Particle Depositions in Severe Asthmatic Lungs

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Sanghun Choi ◽  
Shinjiro Miyawaki ◽  
Ching-Long Lin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Turbulent Flows ◽  
Severe Asthma ◽  
Volume Change ◽  
Healthy Subjects ◽  
Particle Deposition ◽  
Specific Flow ◽  
Cfd Models ◽  
Air Volume

This study aims to investigate the effect of altered structures and functions in severe asthma on particle deposition by using computational fluid dynamics (CFD) models. Airway geometrical models of two healthy subjects and two severe asthmatics were reconstructed from computed tomography (CT) images. Subject-specific flow boundary conditions were obtained by image registration to account for regional functional alterations of severe asthmatics. A large eddy simulation (LES) model for transitional and turbulent flows was applied to simulate airflows, and particle transport simulations were then performed for 2.5, 5, and 10 μm particles using CFD-predicted flow fields. Compared to the healthy subjects, the severe asthmatics had a smaller air-volume change in the lower lobes and a larger air-volume change in the upper lobes. Both severe asthmatics had smaller airway circularity (Cr), but one of them had a significant reduction of hydraulic diameter (Dh). In severe asthmatics, the larger air-volume change in the upper lobes resulted in more particles in the upper lobes, especially for the small 2.5 μm particles. The structural alterations measured by Cr and Dh were associated with a higher particle deposition. Dh was found to be the most important metric which affects the specific location of particle deposition. This study demonstrates the relationship of CT-based structural and functional alterations in severe asthma with flow and particle dynamics.

scholarly journals Experimental Validation Data for Computational Fluid Dynamics of Forced Convection on a Vertical Flat Plate

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Jeff R. Harris ◽  
Blake W. Lance ◽  
Barton L. Smith
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Forced Convection ◽  
Vertical Plate ◽  
Navier Stokes ◽  
Validation Dataset ◽  
System Response ◽  
Cfd Validation ◽  
Validation Data ◽  
Computational Fluid Dynamics Cfd

A computational fluid dynamics (CFD) validation dataset for turbulent forced convection on a vertical plate is presented. The design of the apparatus is based on recent validation literature and provides a means to simultaneously measure boundary conditions (BCs) and system response quantities (SRQs). All important inflow quantities for Reynolds-Averaged Navier-Stokes (RANS). CFD are also measured. Data are acquired at two heating conditions and cover the range 40,000 < Rex < 300,000, 357 <  Reδ2 < 813, and 0.02 < Gr/Re2 < 0.232.

scholarly journals Modelling of working processes of non-contact oil free vacuum pumps by computational fluid dynamics (CFD) methods

2021 ◽  
Vol 2059 (1) ◽  
pp. 012003
Author(s):  
A Burmistrov ◽  
A Raykov ◽  
S Salikeev ◽  
E Kapustin
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Mathematical Models ◽  
Cfd Models ◽  
Ansys Cfx ◽  
Sst Turbulence Model ◽  
Computational Fluid Dynamics Cfd ◽  
Dynamic Meshing ◽  
Comparison With Experimental Data

Abstract Numerical mathematical models of non-contact oil free scroll, Roots and screw vacuum pumps are developed. Modelling was carried out with the help of software CFD ANSYS-CFX and program TwinMesh for dynamic meshing. Pumping characteristics of non-contact pumps in viscous flow with the help of SST-turbulence model were calculated for varying rotors profiles, clearances, and rotating speeds. Comparison with experimental data verified adequacy of developed CFD models.

scholarly journals Computational Fluid Dynamics Model of Wells Turbine for Oscillating Water Column System: A Review

2021 ◽  
Vol 2053 (1) ◽  
pp. 012013
Author(s):  
N. Abdul Settar ◽  
S. Sarip ◽  
H.M. Kaidi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Column ◽  
Cfd Simulation ◽  
Oscillating Water Column ◽  
Wells Turbine ◽  
Flow Problems ◽  
Cfd Models ◽  
Column System ◽  
Cfd Method

Abstract Wells turbine is an important component in the oscillating water column (OWC) system. Thus, many researchers tend to improve the performance via experiment or computational fluid dynamics (CFD) simulation, which is cheaper. As the CFD method becomes more popular, the lack of evidence to support the parameters used during the CFD simulation becomes a big issue. This paper aims to review the CFD models applied to the Wells turbine for the OWC system. Journal papers from the past ten years were summarized in brief critique. As a summary, the FLUENT and CFX software are mostly used to simulate the Wells turbine flow problems while SST k-ω turbulence model is the widely used model. A grid independence test is essential when doing CFD simulation. In conclusion, this review paper can show the research gap for CFD simulation and can reduce the time in selecting suitable parameters when involving simulation in the Wells turbine.

Computational Fluid Dynamics Modeling of Mixed Convection Flows in Building Enclosures

2013 ◽  
Author(s):  
Alexander Kayne ◽  
Ramesh Agarwal
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Mixed Convection ◽  
Turbulence Model ◽  
Numerical Algorithm ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Flow And Heat Transfer

In recent years Computational Fluid Dynamics (CFD) simulations are increasingly used to model the air circulation and temperature environment inside the rooms of residential and office buildings to gain insight into the relative energy consumptions of various HVAC systems for cooling/heating for climate control and thermal comfort. This requires accurate simulation of turbulent flow and heat transfer for various types of ventilation systems using the Reynolds-Averaged Navier-Stokes (RANS) equations of fluid dynamics. Large Eddy Simulation (LES) or Direct Numerical Simulation (DNS) of Navier-Stokes equations is computationally intensive and expensive for simulations of this kind. As a result, vast majority of CFD simulations employ RANS equations in conjunction with a turbulence model. In order to assess the modeling requirements (mesh, numerical algorithm, turbulence model etc.) for accurate simulations, it is critical to validate the calculations against the experimental data. For this purpose, we use three well known benchmark validation cases, one for natural convection in 2D closed vertical cavity, second for forced convection in a 2D rectangular cavity and the third for mixed convection in a 2D square cavity. The simulations are performed on a number of meshes of different density using a number of turbulence models. It is found that k-epsilon two-equation turbulence model with a second-order algorithm on a reasonable mesh gives the best results. This information is then used to determine the modeling requirements (mesh, numerical algorithm, turbulence model etc.) for flows in 3D enclosures with different ventilation systems. In particular two cases are considered for which the experimental data is available. These cases are (1) air flow and heat transfer in a naturally ventilated room and (2) airflow and temperature distribution in an atrium. Good agreement with the experimental data and computations of other investigators is obtained.

Computational Fluid Dynamics Modelling of a Load Sensing Proportional Valve

2019 ◽  
Author(s):  
Alessandro Corvaglia ◽  
Giorgio Altare ◽  
Roberto Finesso ◽  
Massimo Rundo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Complex Geometry ◽  
Ansys Fluent ◽  
Proportional Valve ◽  
Fluid Forces ◽  
Load Sensing ◽  
Cfd Models ◽  
Dynamics Modelling

Abstract In this paper, two 3D CFD models of a load sensing proportional valve are contrasted. The models were developed with two different software, Simerics PumpLinx® and ANSYS Fluent®. In both cases the mesh was dynamically modified based on the fluid forces acting on the local compensator. In the former, a specific template for valves was used, in the latter a user-defined function was implemented. The models were validated in terms of flow rate and pressure drop for different positions of the main spool by means of specific tests. Two configurations were tested: with the local compensator blocked and free to regulate. The study has brought to evidence the reliability of the CFD models in evaluating the steady-state characteristics of valves with complex geometry.

Sign in / Sign up

Export Citation Format

Share Document