CFD Analysis of a Water Flume Design for Testing Marine and Hydrokinetics Energy Converters

2018 ◽  
Author(s):  
Akshith Subramanian ◽  
Navid Goudarzi
Keyword(s):  
Test Section ◽  
Lower Cost ◽  
Performance Metrics ◽  
Experimental Testing ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Design Parameters ◽  
Energy Technologies ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

Marine and hydrokinetic (MHK) energy resources with advantages such as predictability and less variability compared to other forms of renewable energies, have been drawing more interest in recent years. One important phase before commercialization of new MHK technologies is to conduct experimental testing and evaluate their performance in a real environment. In this work, a numerical computational fluid dynamics (CFD) method is used to study the fluid flow behavior within a designed water flume for MHK energy technologies. The water flume design parameters were given by the team collaborators at National Renewable Energy Laboratory (NREL) and Colorado School of Mines. The results from this simulation showed the flow characteristics within the test-section of the proposed water flume design. These results can be used for the follow on phases of this research that includes testing scaled MHK prototypes at different flow rates as well as optimizing either the water flume design to obtain more realistic flow characteristics within the test section or the MHK devices to obtain higher performance metrics at lower cost.

scholarly journals Numerical study of flow characteristics on wing airfoil eppler 562 with whitcomb winglet variations

2018 ◽  
Vol 204 ◽  
pp. 04009
Author(s):  
S.P Setyo Hariyadi ◽  
Sutardi ◽  
Wawan Aries Widodo ◽  
Muhammad Anis Mustaghfirin ◽  
Arifandi Rachmadiyan
Keyword(s):  
Fluid Flow ◽  
Numerical Study ◽  
Fuel Efficiency ◽  
Flow Characteristics ◽  
Lower Surface ◽  
Computational Fluid Dynamics Cfd ◽  
Fluid Flow Characteristics ◽  
Conducting Research ◽  
Cfd Method ◽  
Wing Airfoil

Winglet is a tool used to improve the efficiency of aircraft and UAV performance by preventing fluid flow jump from lower surface to upper surface at wingtip. The addition of this winglet resulted in improved lift and reduction of drag force from the aircraft wing or UAV. From Whitcomb's research, it was found that the use of winglet on a full size airplane can increase fuel efficiency by 7%. The research led to the idea of conducting research on fluid flow characteristics on the UAV wing with the Eppler 562 airfoil combined with the whitcomb winglet. This numerical study was conducted using the Computational Fluid Dynamics (CFD) method based on the advantages of using this simulation that can review the fluid flow in macroscopic way. This study is provide accurate fluid flow visualization results and can improve the performance of the wings when compared with wings without winglet (plain wing). Wing with the Eppler 562 airfoil combined with the whitcomb winglet results reduction in rotating motion that makes velocity components as opposed to lift.

Theoretical and Experimental Studies of a New Configuration of Photovoltaic–Thermal Collector

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Hanene Ben Cheikh El Hocine ◽  
Khaled Touafek ◽  
Fouad Kerrour
Keyword(s):  
Solar Energy ◽  
Lower Cost ◽  
Experimental Studies ◽  
Design Parameters ◽  
Energy Technologies ◽  
Attractive Option ◽  
Computer Simulation Program ◽  
Water Collector ◽  
Vertical Tubes ◽  
Good Agreement

Within the solar energy technologies, the hybrid photovoltaic–thermal (PVT) systems offer an attractive option because the absorbed solar radiation is converted into thermal and electrical energies (the conversion can be done separately or simultaneously). In this study, an attempt has been made to evaluate the theoretical and practical performances and evaluation of a hybrid PVT collector based on a new integrated absorber configuration function of climatic and design parameters. Our objective is to obtain a more efficient use of solar energy by cheaper materials and simpler implementation. On the first hand, we considered two different configurations of hybrid collectors which are defined as PVT water with absorber in parallel vertical tubes (model I) and a PVT with absorber in an enclosure (model II). On the second hand, we presented a new integrated absorber configuration for hybrid collector; then we compared it to the two previous models. The last proposed design has the advantage of a simpler implementation and a lower cost compared to other configurations of PVT hybrid collectors. A computer simulation program has been developed in order to calculate the thermal and electrical parameters of the PVT–water collector. The obtained simulation results are found to be in good agreement with the experimental measurements. For a sample climatic, operating, and design parameter, the calculated thermal and electrical energies of the new configuration of PVT are about 125.36 W and 40 W, respectively.

Two-Phase CFD of Channel Boiling for Boiling Transition Problems

2014 ◽  
Author(s):  
Antonin Povolny ◽  
Martin Cuhra
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
First Principles ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Two Phase ◽  
General Ability ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Traditional Approaches

In order to ensure safety of nuclear installations, thermohydraulics has developed many ways how to predict the behavior of coolant in a heated boiling channel. Accuracy of these predictions can be improved using three-dimensional Computational Fluid Dynamics (CFD) method, which is based on first principles of fluid mechanics. Even though when using CFD, there is a struggle between the accuracy and low computation costs, in many cases CFD can provide feasible improvement of accuracy compared to more traditional approaches. In this research, the focus is set on channel boiling problems, especially those associated with boiling transitions. The phenomenon of critical heat flux (CHF) is investigated using two-phase CFD computation and is compared to experimental data. There is also comparison with other computation methods. When experiment provides some set of data, CFD calculation provides description of the whole flow behavior that provides significantly more information and is of great value during the design process when it gives the understanding of undergoing effects. Besides CHF, general ability of CFD to predict changes in boiling patterns in two-phase channel boiling flows is discussed.

Numerical Simulation on the Parallel Combined Nozzles of Mini/Micro Gas Flow Standard Device

2012 ◽  
Vol 472-475 ◽  
pp. 2000-2003
Author(s):  
Jin Long Meng ◽  
Zhao Qin Yin
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Flow Characteristics ◽  
Micro Gas Flow ◽  
Actual Flow Rate ◽  
Actual Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

The flow characteristics in mini/micro sonic nozzles have been studied in this paper using the computational fluid dynamics (CFD) method. The result shows that the flow rate of the parallel combined nozzles is not equal to but smaller than that of the sum of the nozzles. The reason is the each effect of the air after nozzles, which changes the flow field parameters .The more number of the parallel combined nozzles, the bigger error exits between actual flow rate and that of the sum of the nozzles. The result is consistent to the experiment. The study also shows the smaller of the nozzle’s diameter, the bigger error exits.

Simulation Study on Ventilation & Cooling for an Indoor Substation

2014 ◽  
Vol 672-674 ◽  
pp. 1700-1707 ◽  
Author(s):  
Rui Xu ◽  
Zhong Min Mei ◽  
Ting Fang Yu
Keyword(s):  
Natural Ventilation ◽  
Three Dimensional ◽  
Organization Design ◽  
Temperature Fields ◽  
Design Parameters ◽  
Air Distribution ◽  
Safety And Reliability ◽  
Computational Fluid Dynamics Cfd ◽  
Dimensional Simulation ◽  
Cfd Method

— Based on natural ventilation design scheme for an indoor substation, different air distribution schemes were obtained by changing height and size of air inlets and outlets. For indoor substation, three-dimensional simulation of air distribution was conducted by using Computational Fluid Dynamics (CFD) method. Ventilation & cooling effect of different indoor ventilation schemes were simulated with software (Fluent). By analyzing velocity fields and temperature fields, influences of different design parameters on safety and reliability of main transformer room of indoor substation were compared and analyzed in details. Additionally, characteristics and change rules of air distribution with different parameter variations were concluded. Considerations of ventilation organization design for main transformer room of indoor substation and recommendation for better air distribution schemes were provided. The research results also offered some guidance for design and renovation of ventilation & cooling projects of indoor substation.

Using Computational Fluid Dynamics (CFD) for Evaluation of Fluid Flow Through a Gate Valve

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Pedro Esteves Duarte Augusto ◽  
Marcelo Cristianini
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Gate Valve ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Type Equation ◽  
Pharmaceutical Products ◽  
Computational Fluid Dynamics Cfd

Abstract Gate valves are the most common valve in industrial plants. However, there is no work in the literature regarding the use of computational fluid dynamics (CFD) to evaluate the fluid flow characteristics and pressure drop in gate valves. The present work evaluated the fluid flow and pressure drop through a commercial gate valve using CFD. The obtained values for the pressure loss coefficient (k) are in accordance to those described in the literature and a power type equation could be used for modeling it as function of the Reynolds Number. Fluid flow behavior through the gate valve highlighted the flow recirculation and stagnant areas, being critical for food and pharmaceutical products processing. The obtained results reinforce the advantages in using CFD as a tool for the engineering evaluation of fluid processes.

Investigations on Friction Resistance of Forced Circulation in a Circular Tube Under Inclination and Rolling Conditions

2010 ◽  
Author(s):  
Sijia Du ◽  
Hong Zhang
Keyword(s):  
Test Section ◽  
Flow Characteristics ◽  
Test Tube ◽  
Steel Cylinder ◽  
Forced Circulation ◽  
Flux Boundary Condition ◽  
Number Range ◽  
Friction Resistance ◽  
The Coefficient Of Friction ◽  
Cfd Method

The friction resistance under marine conditions is very important to a marine reactor system in the ocean. The traditional empirical or semi-empirical relationships were used in thermo-hydraulic system programmes at the present time, while the applicability of these relationships under ocean conditions was not validated adequately. Experiments have been conducted to study the friction resistance of forced circulation when the test tube was at inclined attitude and rolling model. The experimental setup consists of stainless steel cylinder tube as test section with 10mm inside diameter and 1200mm length, is subjected to a constant wall heat flux boundary condition. The investigation covers Reynolds number range from 1.0e+4 to 1.2e+5, and the test section angles of inclination including 10°, 20° and 30°, amplitudes of rolling angle including 10°, 15° and 20° with the rolling periods of 10s, 15s and 20s. Pressure drop was measured to calculate the coefficient of friction resistance. CFD method was used to simulate the flow characteristics under inclination and rolling conditions, the results were compared with experimental data. The investigations showed that the influence of inclination and rolling to friction coefficient is not obvious.

scholarly journals Yaw angle effect on the aerodynamic performance of hatchback vehicle fitted with wing spoiler

2019 ◽  
Vol 15 (3) ◽  
pp. 389-393
Author(s):  
Kwang-Yhee Chin ◽  
See-Yuan Cheng ◽  
Shuhaimi Mansor
Keyword(s):  
Lift Coefficient ◽  
Flow Characteristics ◽  
Aerodynamic Performance ◽  
The Other ◽  
Body Parts ◽  
Angle Effect ◽  
Computational Fluid Dynamics Cfd ◽  
The Stability ◽  
Cfd Method ◽  
Yaw Angle

Research on spoiler available to date was mainly done to optimize the performance of spoiler in non-zero yaw condition. However, the effect of spoiler is most needed during cornering to ensure the stability of the vehicle. Therefore, this study aims to inspect the effect of yaw angles change on the aerodynamic performance of the NACA 0018 wing spoiler and the subsequent influence on the flow characteristics of the hatchback vehicle. Computational Fluid Dynamics (CFD) has been applied to model the flow. Comparison between numerically obtained results and experimental data was done to validate the CFD method. The findings show that both the drag coefficient, Cd, and lift coefficient, Cl have increased with increasing yaw angle. However, the spoiler has performed in favor of reducing the Cd and Cl even with increasing yaw angle. The averaged proportion contributions from the spoiler to the overall Cd and Cl are 2.7% and 4.1%, respectively. The other body parts that have contributed to the Cd and Cl reductions were the base and slant, and the roof.

Effect of Leakage Flow Path Wear on Axial Thrust in Downhole Electrical Submersible Pump Unit

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Abhay Patil ◽  
Marie Kasprzyk ◽  
Adolfo Delgado ◽  
Gerald Morrison
Keyword(s):  
Numerical Models ◽  
Experimental Testing ◽  
Flow Characteristics ◽  
Design Parameters ◽  
Test Time ◽  
Axial Thrust ◽  
Erosion Testing ◽  
Electrical Submersible Pump ◽  
Relationship Of ◽  
Thrust Load

Abstract Subsea production fluid is quite often characterized by the presence of frac sand, which causes wear within the pump, and alters the performance envelop. One of the design parameters critically affecting reliability is the thrust load generated by an impeller. The change in thrust load due to the erosion of the pump stages is not completely understood, and no relationship exists to foresee these reactive forces due to the complexity involved in predicting the flow characteristics. The purpose of this study is to understand the change in axial thrust due to commonly encountered wear mechanisms across the pump section especially wear across stage clearance seals. Based on in-house erosion testing of a mixed flow pump, three mesh models were built with each representing the pump condition at three different time intervals, namely, 0 h, 52 h, and 117 h of the total test time. The pump numerical models were validated using performance data collected from experimental testing. Axial thrust was found to increase with an increase in wear rate across stage seals. Since the increased clearance causes head degradation as well as an increase in thrust, the relationship of this head degradation is correlated with a change in thrust to further expand the affinity laws.

Numerical Simulation of Laminar Flow Field in a Stirred Tank with a Rushton Impeller or a Pitch 4-Bladed Turbine

2012 ◽  
Vol 557-559 ◽  
pp. 2375-2382
Author(s):  
Jun Ling Fan ◽  
De Yu Luan
Keyword(s):  
Laminar Flow ◽  
Flow Field ◽  
Equations Of Motion ◽  
Flow Characteristics ◽  
Stirred Tank ◽  
High Power Consumption ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Multiple Reference ◽  
Rushton Impeller

Computational fluid dynamics (CFD) method was applied to the study of flow field in the agitation of glycerin fluid with a Rushton impeller and a pitch 4-bladed turbine. The flow was modeled as laminar and a multiple reference frame (MRF) approach was used to solve the discretized equations of motion. The velocity profiles predicted by the simulation with four different impellers rotating at constant speed of 200r/min were obtained. By analysis to their axial, radial and tangent velocity vector plots, velocity contours and velocity distribution curves, it was found that the stirred effect of the Rushton impeller was better than one of the pitch 4-bladed turbines，however，accompanied with high power consumption according to the calculated values of required power. Moreover, there were all similar flow characteristics for the pitch 4-bladed turbines with different blade pitch angle. The research provided a theoretical basis for the design and practical application of the stirred tank under laminar flow.

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