Optimization, Numerical, and Experimental Study of a Propeller Pump as Turbine

2014 ◽  
Vol 136 (1) ◽  
Author(s):  
Shahram Derakhshan ◽  
Nemat Kasaeian
Keyword(s):  
Energy Production ◽  
Cfd Simulation ◽  
Control Volume ◽  
Design Parameters ◽  
Axial Pump ◽  
Performance Curves ◽  
Turbine Runner ◽  
Low Head ◽  
Computational Fluid Dynamics Cfd ◽  
Installed Capacity

Micro hydropower station is one of the clean choices for offgrid points with available hydropotential. The challenging in this type of energy production is the high capital cost of the installed capacity that is worse for low-head micro hydropower stations. Turbine price is the main problem for this type of energy production. In this research, a simple machine has been introduced instead of conventional propeller turbines. The key is using an axial pump as a propeller turbine. In the present research, a propeller pump was simulated as a turbine by numerical methods. Computational fluid dynamics (CFD) was adopted in the direct and reverse modes performance prediction of a single propeller pump. To give a more accurate CFD result, all domains within the machine control volume were modeled and hexahedral structured mesh was generated during CFD simulation. Complete performance curves of its pump and turbine modes were acquired. For verification of the numerical results, the machine has been tested in an established test ring. The results showed that a propeller pump could be easily run as a low-head turbine. In the next, the goal was to optimize the geometry of the blades of axial turbine runner which leads to maximum hydraulic efficiency by changing the design parameters of camber line in five sections of a blade. The efficiency of the initial geometry was improved by various objective functions and optimized geometry was obtained by genetic algorithm and artificial neural network to find the best efficiency of the turbine. The results showed that the efficiency is improved by more than 14%. Indeed the geometry has better performance in cavitation.

Investigating barotrauma in juvenile salmon passing through a very low head turbine using response surface methodology

2021 ◽  
pp. 095440622110504
Author(s):  
Mehrshad Foroughan ◽  
Alireza Riasi ◽  
Amir Bahreini
Keyword(s):  
Chinook Salmon ◽  
Cfd Simulation ◽  
Geometrical Parameters ◽  
Innovative Design ◽  
Computational Costs ◽  
Water Turbine ◽  
Low Head ◽  
Computational Fluid Dynamics Cfd ◽  
Biological Performance ◽  
Riverine Fish

Although hydropower is a clean source of energy, in some cases, it can jeopardize the life of some species of riverine fish. Very Low Head (VLH) water turbine is an innovative design that aims at reducing the adverse effects of such hydroelectric facilities. In this research, two methodologies are integrated to investigate barotrauma in juvenile salmons passing through this particular turbine. First, to quantify barotrauma, we implement a method known as BioPA (Biological Performance Assessment) by combining the results of some laboratory experiments on juvenile Chinook salmon moving through a simulated turbine passage with the Computational Fluid Dynamics (CFD) simulation of the flow field in this environment. In the second part, we added surrogate-based modeling as a tool, which enabled us to study the effects of two geometrical parameters on the environmental performance of the VLH turbine with low computational costs. The results indicate a significant dependency between the installation angle of the VLH turbine and the severity of the barotrauma of this particular fish. In addition, further investigations suggest that the region near the middle of blades is the safest for fish in the case of decompression.

Numerical Investigations on Intake Tube Design of Micro Kaplan Hydro-Turbine System

2016 ◽  
Author(s):  
Tarek ElGammal ◽  
Yi-Hsin Yen ◽  
Ryoichi S. Amano ◽  
Joseph Millevolte ◽  
Randal J. Mueller ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Numerical Study ◽  
Performance Outcomes ◽  
Design Parameters ◽  
Hydro Turbine ◽  
Eddy Simulation ◽  
Maximum Angle ◽  
Low Head ◽  
System Output ◽  
The Comparative Study

In this context, a numerical study was conducted to predict the performance of a small axial Kaplan hydro-turbine of 30 cm diameter that can be manufactured and installed vertically on a low head water level of less than 3 m. As a CFD simulation scheme, Large Eddy Simulation was selected to solve for the variables of turbulent flow due to its high fidelity performance for capturing time-variable turbulence wakes and eddies. Turbine intake tube dimensioning was primarily studied as an affecting element to maximize energy extraction with the set of initial design parameters. The intake tube was tested at six angles (3, 6, 9, 12, 15, 18 degrees) and four lengths (50, 60, 75, 90 cm). The simulations were performed on a pre-determined water height, one diffuser design, and one set of stator-rotor having a rotational speed of 750 rpm. Maximizing the efficiency of a system with less material cost was the primary goal of the comparative study. After that, bellmouth profile was adopted to find out its influence on the system performance. Outcomes have proven the merit of higher slope per side length in enhancing output power with an average of 2.7 percent by full expansion from minimum to the maximum angle. Moreover, a corresponding marginal efficiency raise was observed by increasing intake slope, while it was found that the system acts poorly with longer intake tubes as both power and efficiency go down. Bellmouth profiles, based on the guidelines of the best straight design, significantly improved system output to reach 81 percent efficiency.

scholarly journals Experiment and CFD simulation of exhaust tube in highvoltage circuit breaker

2018 ◽  
Vol 169 ◽  
pp. 01001
Author(s):  
Xiangyang Ye ◽  
Francesco Pisu ◽  
Stephan Grob ◽  
Mahesh Dhotre ◽  
Javier Mantilla
Keyword(s):  
Fluid Dynamics ◽  
High Performance ◽  
Cfd Simulation ◽  
Circuit Breaker ◽  
Design Parameters ◽  
Pressure Waves ◽  
Pressure Measurements ◽  
Hot Gas ◽  
High Voltage Circuit Breaker ◽  
Computational Fluid Dynamics Cfd

In a high-voltage circuit breaker, the exhaust tube connects the arc zone with the exhaust volume. During the arc interruption process, the exhaust tube transports the hot gas from the arc interruption zone to the exhaust volume through its distributed holes. The design of a high performance exhaust tube in the circuit breaker development aims for well controlled hot gas evacuation mass flow and pressure waves. In this paper, the exhaust tube behaviour is investigated using Computational Fluid Dynamics (CFD). To verify the CFD simulation, a basic experimental study with pressure measurements at different positions of the exhaust tube is performed. Further, the design parameters influencing the exhaust tube behaviour and circuit breaker performance are investigated and discussed.

scholarly journals Thermal 3D CFD Simulation with Active Transparent Façade in Buildings

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2265 ◽  
Author(s):  
Cristina Ramírez-Balas ◽  
Enrique Fernández-Nieto ◽  
Gladys Narbona-Reina ◽  
Juan Sendra ◽  
Rafael Suárez
Keyword(s):  
Cfd Simulation ◽  
Ventilation System ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Original Solution ◽  
General Application ◽  
Computational Fluid Dynamics Cfd ◽  
City Of Refuge ◽  
The City

In recent years active façades have acquired greater importance given their capacity to improve the energy efficiency of buildings. One such type is the so-called Active Transparent Façade (ATF). A 3D numerical model based on computational fluid dynamics (CFD) and the Finite Element Method (FEM) has been generated to simulate the thermal performance of buildings equipped with this type of façade. This model is introduced for general application and allows the design parameters to be adapted for this system. The case study of Le Corbusier’s proposal for the City of Refuge in Paris, the clearest example of previous use of an ATF is examined. In addition, a proposal is presented for the energy improvement of Le Corbusier’s original solution. In order to do so, the conditions for the supply of air into the ATF cavity and in the mechanical ventilation system are assessed to guarantee comfort conditions.

scholarly journals Low-Head Energy Conversion: A Conceptual Design and Laboratory Investigation of a Microtubular Hydro Propeller

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Helena M. Ramos ◽  
Mariana Simão ◽  
Kaloyan N. Kenov
Keyword(s):  
Energy Production ◽  
Experimental Tests ◽  
Scaled Model ◽  
Behaviour Analysis ◽  
Hydrodynamic Behaviour ◽  
Turbine Performance ◽  
Performance Curves ◽  
Low Head ◽  
Turbine Design ◽  
Oil Crises

Low-head microhydro systems for energy production are becoming accepted because of oil crises and new advances in their design and efficiencies. As this is still a new area for development and experimentation, it is important to test and validate the optimal conditions and the hydrodynamic behaviour of such systems under different conditions. The aim of this paper is to present a turbine design validation practise, which researchers and equipment manufactures can use for the hydrodynamic behaviour analysis of new low-head turbines prior to production and application. Laboratory experimental tests and advanced CFD numerical analysis are described for the flow behaviour analysis of a new prototype microtubular propeller. Laboratory experimental results are presented and used for the evaluation of the turbine performance curves. Comparisons between experimental and CFD results are also presented. Finally, an assessment of the hydrodynamic behaviour is made for a scaled model application, using the theory of turbomachine similarity.

Numerical Investigation of Various Coaxial Nozzle Designs for Direct Laser Deposition

2020 ◽  
Author(s):  
Theodore T. Gabor ◽  
Hang-Eun Joe ◽  
Semih Akin ◽  
Martin Byung-Guk Jun ◽  
Kyung-Han Kim ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Tangential Velocity ◽  
Laser Deposition ◽  
Design Parameters ◽  
Two Phase ◽  
Direct Laser Deposition ◽  
Direct Laser ◽  
Tight Focusing ◽  
Computational Fluid Dynamics Cfd ◽  
Inlet Angle

Abstract Direct Laser Deposition (DLD) is a form of metal-based additive manufacturing. The DLD process involves ejecting powder out of a nozzle by means of an compressed gas and irradiating a laser beam to heat up the powder and the substrate. During the powder spray ejection, tight focusing of the powder stream has the potential to improve the DLD process by reducing powder wastage. Thus, nozzle design and computational fluid dynamics (CFD) analysis of the design parameters become important. This study focuses on the numerical simulation of the gas-solid flow inside a coaxial DLD nozzle and how design features of the nozzle affect powder focusing. The two-phase gas/powder flow was analyzed using a Eulerian-Lagrangian scheme. A total of twelve designs were simulated and analyzed through CFD simulation, with features such as inlet angle, inlet offset, and the presence and shape of flow-straightening grooves considered. It was determined that geometry reducing particle tangential velocity such as flow-straightening grooves produce the best focusing effects, whereas offset inlets without the presence of grooves reduces focusing by maximizing particle swirling. Finally, the simulations show that the distribution of powders within the nozzle is also affected by nozzle inlet angle, with horizontal inlets providing more even distribution over inlets angled towards the nozzle tip.

Discretization Error Estimation Using Error Transport Equation

2002 ◽  
Author(s):  
Ismail Celik ◽  
Gusheng Hu
Keyword(s):  
Fluid Dynamics ◽  
Transport Equation ◽  
Cfd Simulation ◽  
Control Volume ◽  
Process Variable ◽  
Discretization Error ◽  
Computational Fluid Dynamics Cfd ◽  
Finite Volume Approach ◽  
Error Transport Equation ◽  
Modified Equation

The goal of this paper is to develop a dynamic algorithm that can be used in conjunction with computational fluid dynamics (CFD) simulation codes to quantify the discretization error in a selected process variable. The focus is on fluid dynamics applications where conservation equations are solved for primitive variables using finite difference and/or control volume approach. A transport equation for the error is formulated and solved along with a localized residual estimation based on modified equation concept. Spatiotemporal evolution of the error distribution is mapped and compared to exact error for various cases. A new method is suggested for deriving the modified equation specifically aimed at using it with commercial CFD codes which use finite volume approach.

scholarly journals Simulasi Performa Turbin Propeller Dengan Sudut Pitch Yang Divariasikan

2020 ◽  
Vol 6 (1) ◽  
pp. 54
Author(s):  
Pribadyo Pribadyo ◽  
Hadiyanto H ◽  
Jamari J
Keyword(s):  
Turbine Blade ◽  
Cfd Simulation ◽  
Power Coefficient ◽  
Design Parameters ◽  
Blade Angle ◽  
Runner Blade ◽  
Turbine Performance ◽  
Turbine Runner ◽  
Turbine Design ◽  
Blade Pitch Angle

 Propeller turbine performance can be improved by changing the turbine design parameters. One method that was developed is to vary the blade angle on the runner's blades. Analysis of the influence of blade angle on propeller turbine performance is done through numerical simulations based on computational fluid dynamics. The simulation is done with variations of propeller turbine blade angles of 180, 230, and 280 at flow rates of 0.08 m/s to 0.5 m/s. Simulation results show turbines with 250 blade angles have the best performance compared to turbine blade angles of 230 and 280. While the turbine blade angles of 230 tend to have higher performance compared to angles of 280 even though both have peak values for the corresponding power coefficient. Keywords—Propeller turbine, runner blade, pitch angle, CFD simulation

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

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