scholarly journals Prediction of Wind Erosion over a Heritage Site: A Case Study of Yongling Mausoleum, China

2019 ◽  
Vol 3 (4) ◽  
pp. 41-57
Author(s):  
Xiaoyu Wang ◽  
Jinzhu Meng ◽  
Tianwei Zhu ◽  
Jingyu Zhang
Keyword(s):  
Wind Erosion ◽  
Cfd Simulation ◽  
Scale Model ◽  
Weather Data ◽  
Cfd Simulations ◽  
Wind Speeds ◽  
Heritage Site ◽  
Heritage Buildings ◽  
Computational Fluid Dynamics Cfd

AbstractTo protect heritage buildings better, a method exploiting computational fluid dynamics (CFD) was developed for the analysis of wind erosion at a heritage site. Over a two-year period, we collected measurements of hourly weather data at Xinbin County to obtain statistics of wind speeds and directions for the Yongling Mausoleum. Subsequent results from CFD simulations show that before greening, with wind speeds reaching 10 m/s, certain structures (southwest-facing corners, doors and windows on open sides, places where swirling winds develop, and eaves of sloping roofs) of four heritage buildings were eroded more severely. With appropriate greening, plants may exert their unique ecological presence to better protect heritage buildings and their historical environments. After greening, the severity of damage to these vulnerable structures by wind was reduced. With wind speeds reaching 10 m/s, the average pressure on the structures of each building was 0.41–27.85 Pa, representing a reduction of 2.4%–75.6% from pressures before greening. We also constructed a 1:500-scale model to verify in experiments the correctness of CFD simulation qualitatively. The CFD simulations were found to provide an effective method to investigate and predict wind erosion of the heritage site.

A Study on the Performance of Stratified Air Conditioning Design in Assembly Halls – A Case Study at the Dazhi Cultural Center in Taiwan

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Indoor Temperature ◽  
Cultural Center ◽  
Computational Fluid Dynamics Cfd

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.

Evaluation of Aerodynamic Characteristics of Mega-Yacht Superstructures by CFD Simulations

2020 ◽  
Vol 36 (04) ◽  
pp. 259-270
Author(s):  
Ahmet Ziya Saydam ◽  
Serhan Gokcay ◽  
Mustafa Insel
Keyword(s):  
Aerodynamic Characteristics ◽  
Temperature Gradients ◽  
Time Dependent ◽  
Navier Stokes ◽  
Noise Generation ◽  
Velocity Data ◽  
Cfd Simulations ◽  
Recent Developments ◽  
Computational Fluid Dynamics Cfd

Air wake distribution around the superstructure of a mega-yacht is a key concern for the designer because of various reasons such as comfort expectations in recreational deck areas, self-noise generation, air pollution and temperature gradients due to exhaust interactions, and safety of helicopter operations such as landing/take off and hovering. The Reynolds-averaged Navier-Stokes (RANS) technique in computational fluid dynamics (CFD) is frequently used in studies on mega-yacht hydrodynamics and aerodynamics with satisfactory results. In this article, a case study is presented for the utilization of CFD in a mega-yacht's superstructure design. The flow field in recreational open areas has been analyzed for the increase in velocity due to the existence of the superstructure. A reduction in self-noise of the mast structure has been aimed by reducing flow separation and vorticity. Time-dependent velocity data obtained with scale-resolving simulations are presented for the evaluation of helicopter landings. The capabilities and limitations of the RANS technique are discussed along with recent developments in modeling approaches.

CFD simulation of empty fuel tanks separation from a trainer jet

2020 ◽  
Vol 92 (10) ◽  
pp. 1459-1468
Author(s):  
Aleksander Olejnik ◽  
Adam Dziubiński ◽  
Łukasz Kiszkowiak
Keyword(s):  
Cfd Simulation ◽  
Body Movement ◽  
Cfd Simulations ◽  
Content Type ◽  
Sequential Release ◽  
Wind Tunnel Data ◽  
Computational Fluid Dynamics Cfd ◽  
External Forces ◽  
Additional Value ◽  
Control Surfaces

Purpose This study aims to create 6-degree of freedom (SDOF) for computational fluid dynamics (CFD) simulations of body movement, and to validate using the experimental data for empty tank separation from I-22 Iryda jet trainer. The procedure has an ability to be modified or extended, to simulate, for example, a sequential release from the joints. Design/methodology/approach A set of CFD simulations are calculated. Both the SDOF procedure and the CFD simulation settings are validated using the wind tunnel data available for the aircraft. Findings The simulation using designed procedure gives predictable results, but offers availability to be modified to represent external forces, i.e. from body interaction or control system without necessity to model the control surfaces. Practical implications The procedure could be used to model the separation of external stores and design the deployment of anti-radar chaff, flares or ejection seats. Originality/value The work presents original work, caused by insufficient abilities of original SDOF procedure in ANSYS code. Additional value is the ability of the procedure to be easily modified.

scholarly journals Thermal management of machine compartment in a built-in refrigerator

2018 ◽  
Vol 240 ◽  
pp. 05005
Author(s):  
Milind Devle ◽  
Ankur Garg ◽  
Darci Cavali
Keyword(s):  
Heat Exchange ◽  
Cfd Simulation ◽  
Heat Extraction ◽  
Free Standing ◽  
Cfd Simulations ◽  
Performance Effectiveness ◽  
Hot Air ◽  
Computational Fluid Dynamics Cfd ◽  
Major Factors ◽  
Side Gap

In general a multi-door refrigerator machine compartment comprises of fan, condenser, compressor, control box, drain tray, and drain tubes. The performance of machine compartment depends upon the efficiency of heat extraction or heat exchange from heat generating components such as condenser and compressor. The efficiency of heat exchange can be improved by addressing two major factors, namely (1) Air bypass and (2) Hot air recirculation. The hot air recirculation in the machine compartment for builtin multi-door refrigerator configuration is the focus of this study. The results from Computational Fluid Dynamics (CFD) simulations show that efficiency of heat exchange for built-in application is lower than that for free-standing configuration. Recirculation of hot air and reduction in airflow are the two major factors which contribute towards the variation in machine compartment performance. The CFD simulations were coupled with Partial Factorial Design of Experiment (DoE) approach to systematically investigate the effect of variables such as (a) side gap and top gap between kitchen cabinetry and the refrigerator, (b) the baffle/flap (i.e. back and bottom of machine compartment) on the performance effectiveness of machine compartment. The results of the simulation provided critical design improvement directions resulting in performance improvement. Furthermore, the CFD simulation results were also compared to test data and the results compared favourably.

Transient CFD Visualization of Fossil Fuel Combustion Simulations

2003 ◽  
Author(s):  
Brian Dotson ◽  
Kent Eshenberg ◽  
Chris Guenther ◽  
Thomas O’Brien
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Cfd Simulation ◽  
Low Cost ◽  
Three Dimensional ◽  
Cfd Simulations ◽  
Projection System ◽  
Computational Fluid Dynamics Cfd ◽  
High Level ◽  
Wall System

The design of high-efficiency lower-emission coal-fed power plants is facilitated by the extensive use of computational fluid dynamics (CFD) simulations. This paper describes work conducted at the National Energy Technology Laboratory (NETL) and Pittsburgh Supercomputing Center (PSC) to provide an environment for the immersive three-dimensional visualization of CFD simulation results. A low-cost high-resolution projection system has been developed in the visualization lab at NETL. This multi-wall system consists of four projection screens, three of which are tiled into four quadrants. The graphics for the multi-wall system are rendered using a cluster of eight personal computers. A high-level visualization interface named Mavis has also been developed to combine the powerful 3D modules of OpenDX with methods developed at NETL for studying multiphase CFD data. With Python, a completely new OpenDX user interface was built that extends and simplifies the features of a basic graphics library.

scholarly journals ENVIRONMENTAL MICROCLIMATE MANAGEMENT AND RISK IN THE UNESCO WORLD HERITAGE SITE OF VILLA BARBARO MASER (ITALY)

2019 ◽  
Vol XLII-2/W11 ◽  
pp. 269-276
Author(s):  
A. Bonora ◽  
K. Fabbri ◽  
M. Pretelli
Keyword(s):  
Simulated Data ◽  
World Heritage ◽  
World Heritage Site ◽  
Andrea Palladio ◽  
Unesco World Heritage ◽  
Heritage Site ◽  
Unesco World Heritage Site ◽  
Heritage Buildings ◽  
Definition Of

<p><strong>Abstract.</strong> Indoor environment in heritage buildings can be cause of damage for architecture and artefacts which depend on several physical and chemical parameters: air temperature, relative humidity, volatile organic compounds, etc. How is it possible to evaluate their damage, or the risk of damages? How “aggressive” is indoor microclimate? The scientific literature proposes several different criteria for the evaluation of the risk of damages, especially in the field of museums, while there are few studies which take into consideration historic buildings. In this paper we propose an index – the Heritage indoor Microclimate Risk (HMR) – that allows to define the risk concerning the whole environment and not only the artefacts. Moreover, we propose its application to a real case study of a UNESCO Heritage World Site, obtained through indoor microclimate on-site monitoring and building simulation. The case study reported is Villa Barbaro, built in Maser (1554–1560) by the architect Andrea Palladio and registered in the UNESCO World Heritage Site list since 1996, as Palladian Villa of Veneto. The research is structured as follows: monitoring campaign of the microclimatic parameters; virtual modelling of Villa Barbaro and its validation (by comparing the simulated data and the monitored ones); construction of scenarios which can aid to guarantee the historic building’s conservation and the occupants’ comfort; definition of HMR. The innovative aspect of the proposed methodology is the use of a virtual building model of heritage buildings, to determine, through a single index, the degree of risk and the level of indoor microclimate aggression.</p>

scholarly journals The Efficient Application of an Impulse Source Wavemaker to CFD Simulations

2019 ◽  
Author(s):  
Pál Schmitt ◽  
Christian Windt ◽  
Josh Davidson ◽  
John V. Ringwood ◽  
Trevor Whittaker
Keyword(s):  
Shallow Water ◽  
Source Function ◽  
Cfd Simulation ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Wide Range ◽  
Rans Models ◽  
Hydrodynamic Processes ◽  
Computational Fluid Dynamics Cfd ◽  
Shallow Water Models

Computational Fluid Dynamics (CFD) simulations, based on Reynolds Averaged Navier Stokes (RANS) models, are a useful tool for a wide range of coastal and offshore applications, providing a high fidelity representation of the underlying hydrodynamic processes. Generating input waves in the CFD simulation is performed by a numerical wavemaker (NWM), with a variety of different NWM methods existing for this task. While NWMs, based on impulse source methods, have been widely applied for wave generation in depth averaged, shallow water models, they have not seen the same level of adoption in the more general RANS based CFD simulations, due to difficulties in relating the required impulse source function to the resulting free surface elevation for non-shallow water cases. This paper presents an implementation of an impulse source wavemaker, which is able to self-calibrate the impulse source function to produce a desired wave series in deep or shallow water at a specific point in time and space. Example applications are presented, for a numerical wave tank (NWT), based on the opensource CFD software OpenFOAM, for wave packets in deep and shallow water, highlighting the correct calibration of phase and amplitude. Also, the suitability for cases requiring very low reflection from NWT boundaries is demonstrated. Possible issues in the use of the method are discussed and guidance for good application is given.

CFD Simulation of Slug Dissipation in an Enlarged Impacting Tee

2019 ◽  
Author(s):  
Mobina Mohammadikharkeshi ◽  
Mazdak Parsi ◽  
Ramin Dabirian ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Experimental Data ◽  
Void Fraction ◽  
Cfd Simulation ◽  
Petroleum Industry ◽  
Production Operation ◽  
Cfd Simulations ◽  
Ansys Fluent ◽  
Transient Model ◽  
Diameter Pipe ◽  
Computational Fluid Dynamics Cfd

Abstract Slug flow, which commonly occurs in the petroleum industry, is not always a desired flow pattern due to production operation problems it may cause in pipelines and processing facilities. To mitigate these problems, flow conditioning devices such as multiphase flow manifolds and slug catchers are used, where dissipation of slugs occurs in downward flow or in larger diameter pipe sections. Tee-junctions are important parts of these flow conditioning devices. In this work, Computational Fluid Dynamics (CFD) simulations are conducted using ANSYS/FLUENT 17.2 to investigate slug dissipation in an Enlarged Impacting Tee-Junction (EIT). An Eulerian–Eulerian MultiFluid VOF transient model in conjunction with the standard k-ε turbulent model is used to simulate slug dissipation in an EIT geometry. The EIT consists of a 0.05 m ID 10 m long inlet, which is connected to the center of a 0.074 m ID 5.5 m long section that forms the EIT branches. Moreover, experimental data are acquired on slug dissipation lengths in a horizontal EIT with a similar geometry as in the CFD simulations. The CFD results include the mean void fraction and cross-sectionally averaged void fraction time series in the EIT for different gas and liquid velocities. These results provide the inlet slug length and dissipation length in the EIT branches. The CFD results are evaluated against the experimental data demonstrating that the slug dissipation occurring in EIT branches can be predicted by simulation.

CFD Simulation of Segregation in Particulate Multiphase Flows With Binary Solids

2005 ◽  
Author(s):  
Zuoxin Hao
Keyword(s):  
Multiphase Flow ◽  
Cfd Simulation ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Primary Objective ◽  
Cfd Simulations ◽  
Separation Processes ◽  
Solid Mixture ◽  
Computational Fluid Dynamics Cfd ◽  
Realistic Prediction

Segregation in particulate multiphase flow with binary solid mixture has extensive applications in industrial separation processes. Up to now there have been few attempts towards numerical simulation of segregation in particulate multiphase flow with binary mixture due to complexity of the problem. In view of this, the primary objective of present work is to simulate the problem by computational fluid dynamics (CFD) and to validate by comparison with experimental measurements. Eulerian-Eulerian approach, incorporating the granular temperature, an essential ingredient in the solids pressure and solids viscosity formulation, was used to model the flow field of multiphase flow and was solved by Fluent 6.0. The CFD simulation results have been validated by experiments of liquid fluidization of binary solid mixtures. Validation results show that CFD simulation predict segregation and solid volume fraction profile precisely, and in addition, it can supply a more realistic prediction of other hydrodynamic features of the multiphase flow, such as velocity vector of all phases and pressure drop. The success of such CFD simulations opens doors for many potential studies.

CFD and Experimental Analysis of Centrifugal Fans With Forward Curved Blades Used in Electric Motors

2019 ◽  
Author(s):  
S. S. Borges
Keyword(s):  
Cfd Simulation ◽  
Experimental Tests ◽  
Performance Comparison ◽  
Centrifugal Fan ◽  
Electric Motors ◽  
Cfd Simulations ◽  
Interface Models ◽  
Ansys Cfx ◽  
Centrifugal Fans ◽  
Computational Fluid Dynamics Cfd

Abstract This work presents an analysis of the aerodynamic performance of a centrifugal fan with forward curved blades (Sirocco) applied to electric motors. In this analysis were carried out computational fluid dynamics (CFD) simulations and experimental tests for comparison of results. The focus of this analysis is the performance comparison among three different models of general connection interface that are required for the connection between the grids of the rotating and stationary domains of CFD simulation, considering the method adopted by the Ansys CFX, software used as computational tool. Thereby, Frozen Rotor, Stage, and Transient Rotor-Stator were the interface models evaluated. For comparison reference, the experimental data were used to evaluate the performance of each interface models for overall operating range of the fan.

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