Optimization of Kaplan Hydro-Turbine at Very Low Head With Rim-Driven Generator

2017 ◽  
Author(s):  
Ahmad I. Abbas ◽  
Tomoki Sakamoto ◽  
Mandana S. Saravani ◽  
Ryoichi S. Amano ◽  
Joseph Millevolte ◽  
...  
Keyword(s):  
Maximum Output Power ◽  
Design Parameters ◽  
Maximum Output ◽  
Original Design ◽  
Design And Optimization ◽  
Hydro Turbine ◽  
Eddy Simulation ◽  
Low Head ◽  
Manufacturing Techniques ◽  
Design Customization

The objective of the paper is to study the design and optimization of Kaplan hydro turbines for very low head (less than 3 meters), with a particular emphasis on the use of rim-drive electrical generators. The work is based on Computation Fluid Dynamics (CFD) analysis of a variety of design parameters for maximum output power and efficiency. Two designs are presented in the paper. One is a 90-cm (35-inch) diameter vertical-oriented Kaplan hydro turbine systems as an intended product capable of generating over 50 kW. The other is a smaller, 7.6-cm (3-inch) diameter horizontal-oriented system for prototyping and laboratory verification. Both are analyzed through CFD based on Large Eddy Simulation (LES) of transient turbulence. Certain design for the runner and the stator as well as guide vanes upstream of the turbine were studied to get the most from the available head. The intent is to use 3D-printing manufacturing techniques, which may offer original design opportunities as well as the possibility of turbine and water conduit design customization as a function of the head and flow available from a specific site.

Optimization of Kaplan Hydroturbine at Very Low Head With Rim-Driven Generator

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Ahmad I. Abbas ◽  
Ryoichi S. Amano ◽  
Mandana S. Saravani ◽  
Mohammad D. Qandil ◽  
Tomoki Sakamoto
Keyword(s):  
Power Output ◽  
Rotational Speed ◽  
Maximum Output Power ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Maximum Output ◽  
Cfd Analysis ◽  
Original Design ◽  
Speed Range ◽  
Low Head

The objective of the paper is to study the design and optimization of Kaplan hydroturbines for a very low head (less than 3 m), with a particular emphasis on the use of rim-drive electrical generators. The work is based on an experimental setup and computational fluid dynamics (CFD) analysis of various design parameters for maximum output power and efficiency. Two designs are presented in this paper. One is a 90-cm (35-in.) diameter vertical-oriented Kaplan hydroturbine system as an intended product capable of generating over 50 kW. The other is a smaller, 7.6-cm (3-in.) diameter horizontal-oriented system for prototyping and laboratory verification. Both are analyzed through CFD based on large eddy simulation (LES) of transient turbulence. Specific design for the runner and the stator, intake tube shape, as well as guide vanes upstream of the turbine was studied to get the most from the available head. The intent is to use 3D-printing manufacturing techniques, which may offer original design opportunities as well as the possibility of turbine and water conduit design customization as a function of the head and flow available from a specific site. Based on the CFD analysis, the 7.6-cm diameter system achieved the highest power output and the maximum efficiency at the rotational speed range of 1500–2000 rpm, while for the experimental testing, the optimum rotational speed range was 1000–1500 rpm. Because of the mismatch between CFD and experimental results, the CFD results were correlated due to the presence of air and friction; moreover, error and uncertainty analysis were presented for both methods. For the 90-cm case, the optimum performance was found at a rotational speed around 350 rpm according to the CFD results. Finally, investigating the shape of the intake tube of the hydroturbine setup can significantly increase the power output and the efficiency of the system.

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 Numerical optimization of the piezoelectric generators

2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060016
Author(s):  
V. A. Chebanenko ◽  
I. V. Zhilyaev ◽  
A. N. Soloviev ◽  
A. V. Cherpakov ◽  
I. A. Parinov
Keyword(s):  
Finite Element Method ◽  
Numerical Optimization ◽  
Output Voltage ◽  
Optimization Problem ◽  
Optimization Technique ◽  
Maximum Output Power ◽  
Operating Conditions ◽  
Design Parameters ◽  
Maximum Output ◽  
The Finite Element Method

This paper presents the application of the Pareto-based multicriteria optimization technique to problems of increasing the efficiency of piezoelectric generators (PEGs). The optimization problem was solved for two types of generators: cantilever and stack. For the cantilever generator, the task was to optimize the design in such a way as to obtain the maximum output power for a given mechanical excitation. The optimization process was divided into several stages, which significantly reduced the amount of calculations. The task of optimizing the stack type for a given form of mechanical loading consisted in finding the geometric parameters of the generator at which the output voltage and power would be maximum. In the result of solving both problems, sets of geometric design parameters of PEGs were obtained, on the basis of which efficient transducers can be developed for specific operating conditions. It turned out that this technique is more suitable for optimizing the design of cantilever generators than for stack ones in given constraints. The solution of both problems was realized using the finite element method.

scholarly journals Effects of Design Parameters on Fuel Economy and Output Power in an Automotive Thermoelectric Generator

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3274 ◽  
Author(s):  
Martí Comamala ◽  
Ivan Ruiz Cózar ◽  
Albert Massaguer ◽  
Eduard Massaguer ◽  
Toni Pujol
Keyword(s):  
Fuel Consumption ◽  
Output Power ◽  
Fuel Economy ◽  
Waste Heat ◽  
Maximum Output Power ◽  
Back Pressure ◽  
Design Parameters ◽  
Limiting Factor ◽  
Maximum Output ◽  
Sustainable Mobility

The need for more sustainable mobility promoted research into the use of waste heat to reduce emissions and fuel consumption. As such, thermoelectric generation is a promising technique thanks to its robustness and simplicity. Automotive thermoelectric generators (ATEGs) are installed in the tailpipe and convert heat directly into electricity. Previous works on ATEGs mainly focused on extracting the maximum amount of electrical power. However, the back pressure caused by the ATEG heavily influences fuel consumption. Here, an ATEG numerical model was first validated with experimental data and then applied to investigate the effects that modifying the main ATEG design parameters had on both fuel economy and output power. The cooling flow rate and the geometrical dimensions of the heat exchanger on the hot side and the cold side of the ATEG were varied. The design that produced the maximum output power differed from that which maximized fuel economy. Back pressure was the most limiting factor in attaining fuel savings. Back pressure values lower than 5 mbar led to a < 0.2% increase in fuel consumption. In the ATEG design analyzed here, the generation of electrical output power reduced fuel consumption by a maximum of 0.5%.

scholarly journals Optimization Design for Ocean Wave Energy Convertor

2020 ◽  
Vol 185 ◽  
pp. 01073
Author(s):  
Na Liu ◽  
Yimin Tan ◽  
Weiqiang Mo ◽  
Huanqing Han ◽  
Lin Li
Keyword(s):  
Energy Conversion ◽  
Wave Energy ◽  
Simulated Annealing Algorithm ◽  
Maximum Output Power ◽  
Ocean Wave ◽  
Design Parameters ◽  
Maximum Output ◽  
Magnetic Vector Potential ◽  
Linear Generator ◽  
Ocean Wave Energy

Establishing a theoretical model for Ocean Wave Energy Convertor in advance is a necessary step during studying the energy harvesting of ocean wave which can save the engineering cost and improve research efficiency. Since low energy conversion efficiency existed in wave energy convertor when capturing ocean wave energy, the mechanism of slotless Halbach linear generator which can optimize the magnetic field distribution of the generator is adopted as the secondary energy conversion devices to solve the problem. The magnetic vector potential theory is introduced to analysis the topology of Halbach linear generator, then expressions of the generator’s performance have been deduced. Hence, the analysis model of the Halbach linear generator has been settled. To obtain the global optimal solution, the simulated annealing algorithm has been used to slove that derived model. Then a series of linear generator’s design parameters are fixed, which include dimensions of permanent magnets and winding coils. The error of linear generator’s peak power between analytical solution results and simulation results is about 3.6%. The experiment result demonstrates that maximum output power of optimized Halbach linear generator reaches 570w.

scholarly journals Design, fabrication and testing of hydro turbine with composite path runner for ultra-low head application

2019 ◽  
Vol 2 (1) ◽  
pp. 119-125
Author(s):  
Raj Kumar Chaulagain ◽  
Dhiraj Pokhrel ◽  
Kaurab Gautam ◽  
Nabin Khanal ◽  
Harish Bhatt
Keyword(s):  
Guide Vane ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Guide Vanes ◽  
Hydro Turbine ◽  
Ansys Simulation ◽  
Starting Point ◽  
Blade Width ◽  
Low Head ◽  
Bagmati River

This paper is focused on design a turbine with composite path runner for ultra low head application and finally analyze its performance under different test conditions. Literature review was the starting point of research and detailed design parameters for the turbine dimensions and materials were selected taking feasibility of fabrication and testing in hand. The testing was proposed on real site of Bagmati river at Kupandole, Lalitpur, Nepal where the turbine was subjected to fuse reeflowing water from the head of 1.3m and flowrate of 78 LPS that taken as site parameter. The 3D model for the turbine was developed in CATIA. For turbine height of 0.77m and runner minor diameter of 0.152m, simulations were carried out to find the most feasible number of blades, blade width, blade spacing, number of guide vanes and guide vane spacing using ANSYS simulation. Among the simulation the best arrangement was blade radial width of 62 mm, blade spacing of 54mm, guide vane spacing of 36.5 mm, total number of blades 25 and total number of guide vanes 7 keeping output power in mind. The experimental results were then compared with the data obtained from calculations and simulations. Turbine at part load of Qo/Qmax = 0.67 was tested and the resulting maximum efficiency was 21.1% at 87 RPM with available flow rate of 52 LPS.

Characterization of microwave-sintered ceramic composites

1993 ◽  
Vol 51 ◽  
pp. 1136-1137
Author(s):  
X. Zhang ◽  
Y. Pan ◽  
T.T. Meek
Keyword(s):  
Matrix Material ◽  
Maximum Output Power ◽  
Ceramic Matrix Composite ◽  
Ceramic Composites ◽  
Processing Technique ◽  
Structure Characterization ◽  
Alumina Powder ◽  
Maximum Output ◽  
Sintered Ceramic

Industrial microwave heating technology has emerged as a new ceramic processing technique. The unique advantages of fast sintering, high density, and improved materials properties makes it superior in certain respects to other processing methods. This work presents the structure characterization of a microwave sintered ceramic matrix composite.Commercial α-alumina powder A-16 (Alcoa) is chosen as the matrix material, β-silicon carbide whiskers (Third Millennium Technologies, Inc.) are used as the reinforcing element. The green samples consisted of 90 vol% Al2O3 powder and 10 vol% ultrasonically-dispersed SiC whiskers. The powder mixture is blended together, and then uniaxially pressed into a cylindrical pellet under a pressure of 230 MPa, which yields a 52% green density. The sintering experiments are carried out using an industry microwave system (Gober, Model S6F) which generates microwave radiation at 2.45 GHz with a maximum output power of 6 kW. The composites are sintered at two different temperatures (1550°C and 1650°C) with various isothermal processing time intervals ranging from 10 to 20 min.

scholarly journals Geometric Design-based Dimensional Synthesis of a Novel Metamorphic Multi-fingered Hand with Maximal Workspace

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Wei An ◽  
Jun Wei ◽  
Xiaoyu Lu ◽  
Jian S. Dai ◽  
Yanzeng Li
Keyword(s):  
Geometric Design ◽  
Practical Significance ◽  
Design Parameters ◽  
Control Algorithms ◽  
Discretization Method ◽  
Dimensional Synthesis ◽  
Symmetrical Structure ◽  
Design And Optimization ◽  
Total Length

AbstractCurrent research on robotic dexterous hands mainly focuses on designing new finger and palm structures, as well as developing smarter control algorithms. Although the dimensional synthesis of dexterous hands with traditional rigid palms has been carried out, research on the dimensional synthesis of dexterous hands with metamorphic palms remains insufficient. This study investigated the dimensional synthesis of a palm of a novel metamorphic multi-fingered hand, and explored the geometric design for maximizing the precision manipulation workspace. Different indexes were used to value the workspace of the metamorphic hand, and the best proportions between the five links of the palm to obtain the optimal workspace of the metamorphic hand were explored. Based on the fixed total length of the palm member, four nondimensional design parameters that determine the size of the palm were introduced; through the discretization method, the influence of the four design parameters on the workspace of the metamorphic hand with full-actuated fingers and under-actuated fingers was analyzed. Based on the analysis of the metamorphic multi-fingered hand, the symmetrical structure of the palm was designed, resulting in the largest workspace of the multi-fingered hand, and proved that the metamorphic palm has a massive upgrade for the workspace of underactuated fingers. This research contributed to the dimensional synthesis of metamorphic dexterous hands, with practical significance for the design and optimization of novel metamorphic hands.

scholarly journals Design and optimization of differential capacitive micro accelerometer for vibration measurement

2021 ◽  
Vol 30 (1) ◽  
pp. 19-27
Author(s):  
Kumar Gomathi ◽  
Arunachalam Balaji ◽  
Thangaraj Mrunalini
Keyword(s):  
Software Design ◽  
Proof Mass ◽  
Vibration Measurement ◽  
Design Parameters ◽  
Mechanical Sensitivity ◽  
Design And Optimization ◽  
Capacitive Accelerometer ◽  
Cross Axis ◽  
Micro Accelerometer

Abstract This paper deals with the design and optimization of a differential capacitive micro accelerometer for better displacement since other types of micro accelerometer lags in sensitivity and linearity. To overcome this problem, a capacitive area-changed technique is adopted to improve the sensitivity even in a wide acceleration range (0–100 g). The linearity is improved by designing a U-folded suspension. The movable mass of the accelerometer is designed with many fingers connected in parallel and suspended over the stationary electrodes. This arrangement gives the differential comb-type capacitive accelerometer. The area changed capacitive accelerometer is designed using Intellisuite 8.6 Software. Design parameters such as spring width and radius, length, and width of the proof mass are optimized using Minitab 17 software. Mechanical sensitivity of 0.3506 μm/g and Electrical sensitivity of 4.706 μF/g are achieved. The highest displacement of 7.899 μm is obtained with a cross-axis sensitivity of 0.47%.

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