Kaplan Type Research Articles

Implementation of Kaplan Type Ducted Propeller on Hydrodynamics of Offshore Supply Vessel (OSV)

Implementation of Kaplan Type Ducted Propeller on Hydrodynamics of Offshore Supply Vessel (OSV)

Kajian Pemanfaatan Debit pada Saluran Irigasi untuk Pembangkit Listrik Tenaga Mikrohidro (Studi Kasus Saluran Induk Sawito Daerah Irigasi Sadang) Kabupaten Pinrang, Propinsi Sulawesi Selatan

Utilization of water as a new power plant reaches about 6.9% of the existing potential and most of it is built in rivers with very large costs and quite a long time. The demand for electricity is increasing more and more, but the government cannot add power plants from fossil fuels. In fact, they will gradually close all of them and replace them with new renewable energy plants, such as hydropower, solar power, PLTB and other renewable energy power plants. In general, hydroelectric power plants (PLTA) are built on river bodies in the form of weirs or weirs so that they require considerable cost, time and risk and are greatly influenced by fluctuations in discharge, sediment and so on. While there are many irrigation areas that have operated with discharge capacity and fall height that can be utilized for small-scale hydropower, one of them is the Sadang Irrigation Area with an area of ±64,000ha. Using topographic mapping methods, measuring surveys of existing channels, and analyzing the availability of discharge and irrigation water requirements, the research results showed that the height of falls in several irrigation buildings was obtained. By analyzing water availability and demand (water balance), a water supply plan for each existing irrigation canal is obtained. so that the potential power and electrical energy produced is obtained. The Sadang irrigation area is supplied with water from the Benteng weir through two intake buildings. The right intake building supplies the Pekkabata main channel, while the Sawito and Rappang Ha main channels are supplied from the left intake building. The Pekkabata sub-network has a potential power of 338 kW, the Rappang sub-network has a potential power of 158 kW and the Sawito sub-network has a power of 1,939 kW. So the total potential electrical power in the Sadang irrigation network is 2,436 Kw. The potential that has been developed in the Sadang irrigation area for electricity generation is 1,235 kW so there is still a potential of 1,200 kW. Especially in the Sawito main channel, in the building for tapping BSa. 9 has an electrical potential with a power of 492 kW, and annual energy production of 3,511,880 kWh, and the suitable turbine type is the kaplan type.

A New Cross-Flow Type Turbine for Ultra-Low Head in Streams and Channels

In the last few decades, hydropower production has been moving toward a new paradigm of low and diffused power density production of energy with small and mini-hydro plants, which usually do not require significant water storage. In the case of nominal power lower than 20 kW and ultra-low head H (H < 5 m), Archimedes screw or Kaplan type turbines are usually chosen due to their efficiency, which is higher than 0.85. A new cross-flow type turbine called Ultra-low Power Recovery System (UL-PRS) is proposed and its geometry and design criteria are validated in a wide range of operating conditions through 2D numerical analysis computed using the ANSYS Fluent solver. The new proposed solution is much simpler than the previously mentioned competitors; its outlet flow has a horizontal direction and attains similar efficiency. The costs of the UL-PRS turbine are compared with the costs of one Kaplan and one cross-flow turbine (CFT) in the case study of the main water treatment plant of the city of Palermo in Italy. In this case, the UL-PRS efficiency is estimated using a URANS 3D numerical analysis computed with the CFX solver.

A Validation Simulation using OpenFOAM: Nozzle Length and Angle Effect on the Ducted Propeller Performance

The use of numerical simulation is needed for predicting the performance of the ship. The Computational Fluid Dynamics (CFD) method is based on the improvement of Reynold-Average Navier Stokes (RANS) equation, in order to compute the simulation for solving the engineering problem. The simulation was begun by conducting several calculations to validate the numerical method applied in open water propeller test. A Kaplan type propeller is selected with 19A nozzle. The Moving Rotating Frame (MRF) method was selected to test the ducted propeller performance by modifying the nozzle length and angle. The model was designed in Computer-Aided Design (CAD) program and predicted the performance using the OpenFOAM. The OpenFOAM was used as open source CFD tool. The results are validated by comparing with experimental value of J from 0.2 to 0.8 and produced the thrust, torque and efficiency trends in good agreement with experimental data. Due to the results, can be conclude that by increasing the nozzle length to 10% and 20%, the thrust was decreased about 2.25% and 3.01% at low advance coefficient to 7.06% and 9.41% at high advance coefficient. By increasing the nozzle angle, both thrust and torque were increased while efficiency decreased especially at low coefficient.

On the auto-oscillation effect of Kaplan rotors during load rejection

High vibrations due to auto-oscillation effects can occur at power units with Kaplan type runner during load rejection. These vibrations may be present in the turbine braking mode when the wicket gates are almost closed, and the rotating runner pushes the water towards the draft tube resulting in higher pressure below the runner blades. The upward leakage flow between runner blades and discharge ring is suspected to cause the vibration phenomenon.Within this contribution, a fluid-structure-interaction (FSI) technique is applied to identify the mechanism of self-excitation. The investigation is carried out on a disk that represents the simplified geometry of a Kaplan runner. Computational fluid dynamics (CFD) simulations are used in order to obtain parameters in terms of stiffness, damping and inertia of the fluid to be applied in the following shaft line analysis. Damped modal analyses of the shaft line allow for evaluation of the stability of natural frequencies and corresponding mode shapes of the shaft line. A resulting negative damping indicates the occurrence of auto-oscillation behavior of the shaft line. For the operating condition under investigation, mode shapes with negative damping are obtained with this approach and a dynamic bending moment on the runner due to lateral movement in combination with a tilting at the runner in these mode shapes is identified as source of instability.Based on these findings, an analytical approach for modeling the relevant effect is derived and compared to CFD result as well as results from acoustic finite element modelling. Finally, conclusions for avoidance of self-excited vibrations at Kaplan runners are proposed.

Unusual Anastomosis between Branches of the Ulnar Nerve (Kaplan Type Anastomotic Variant) - Case Report.

The Kaplan anastomosis is a rare communication originally described between the superficial and dorsal branches of the ulnar nerve, distal to the ulnar tunnel, and in strict relation with the pisiform bone. It reveals, by its particular location, a formation of high clinical-surgical expressiveness. In this paper, we describe a Kaplan-type communication from a left upper limb with an unusual loop conformation between branches of the ulnar nerve in the pisiform bone.

PENGARUH VARIASI SUDUT BUKAAN GUIDE VANE TERHADAP KINERJA PROTOTYPE PLTMH DENGAN TURBIN KAPLAN

The increase in the need for electrical energy in Indonesia is increasing along withpopulation growth. Followed by the depletion of fuels originating from fossil energy. Based ongeographic conditions, Indonesia has many rivers so that it has the potential to generateelectricity by utilizing the flow of water which is called PLTMH (Microhydro Power Plant). Inrealizing this PLTMH, one type of water turbine can be used, namely the Kaplan turbine, wherethis type of turbine works at low head conditions with large discharge. The purpose of thisresearch is to analyze the performance of the Kaplan type turbine guide vane prototype atangles of 15º, 30º, 45º, 60º, 75º, and 90º to meet the electricity demand in Indonesia. Afterbeing examined based on all the variations tested, the maximum value of the turbine rotationalspeed at an opening of 15º with the rotation values obtained before and after coupled with thegenerator were 249.5 rpm and 216.5 rpm. The value of the generator rotation before and afterthe 30 Watt load coupling is 1096.6 rpm and 999 rpm. Voltage, current, and power producedare 9,1 Volts, 0,68 Amperes, and 6,18 Watts. The resulting torque of 0,27 Nm. The greatestefficiency was obtained at a combination of the opening angle of the guide vane of 15º at2,62%.

Construction of Kaplan turbine test bench for mini hydraulic power generation

The general objective of the work was the design, development, and construction of a Test Bench for Kaplan type turbines suitable to be installed in a rural environment, through which we can check if the characteristics of the turbines are ideal to meet the generation goals of electrical power required. To carry out this purpose, a Kaplan-type turbine prototype was designed and built-in order to install it in our Test Bench and verify that this Bench is adequate to check the operation of the turbine subjected to different input conditions and for Therefore, this will help us to arrive at an ideal turbine design to take advantage of the mechanical energy of water and therefore the generation of electrical energy. This is a project that was developed with the design objectives from scratch to the physical creation of a test bench for turbines, specifically for a Kaplan type turbine where tests can be carried out in a controlled environment where new designs are put into practice. of turbines to know their operation in a scaled manner and then be able to take them to production and installation in different regions.

Effect of Nozzle Performance on the Ducted Propeller: A Benchmark-Simulation Study using OpenFOAM

As the modernization of marine transportation, it should be needed the strategy to improve the marine vehicle performances. The propeller is one of the important parts which has a function as an actuator during the operation of marine transportation or vehicle. The propeller design and optimization are packages to gain the best performances, included for the ducted propeller. Since the Nozzle design is one of the crucial aspects that influences the efficiency of the propeller. In the present study, the nozzle design has been proposed by using moving the propeller location based on the percentage of duct length. The propeller and nozzle were modelled in Computer-Aided Design (CAD) program packages and was testing to predict the performance using the OpenFOAM computational fluid dynamics (CFD) with Reynold-Average Navier-Stokes (RANS) method. A Kaplan type propeller is selected with 19A duct. The ducted propeller is analyzed by the Moving Rotating Frame (MRF). The computational results are validated by comparing with the experimental value of J from 0.2 to 0.8. The reasonable results were produced such the thrust, torque and efficiency trends were in good agreement with experimental data. According to the analysis, it can be concluded that by increasing 3% the duct length of the thrust increases about 2.148%

Hydropower Potential on Agricultural Dam: An Evaluation for Pedu Dam

In line with its continuous GDP increase, the growth in electricity demand has shown a similar trend of annual increment for Malaysia. With the projected continuous increase of electricity demand, more fossil fuel-based power plants are committed to be built in the near future. To mitigate the resulting greenhouse gas emission from increasing demand, exploiting existing agricultural dam initially built for agricultural purposes for energy can be considered as an option. This study shows the potential of generating electricity from Pedu dam located in Kedah, initially built with the objective to harvest paddy twice annually. The study shows that there is a potential of 156,072MWh to be generated from the dam water release, with the power of 33,155kW and a capacity factor of 53.7%, using Kaplan type turbine.

Utilization of Hydroturbines in Wastewater Treatment Plants

Wastewater treatment plants (WWTPs) are a significant energy consumer, yet there are several opportunities for implementing on-site power generation systems. Within the treatment process, the high flow rate of effluent is produced and discharged to a nearby water body by gravity. Thus, hydroturbines can be utilized to generate power in such an application due to a difference in elevation and high flow rate. This paper presents a case study of introducing a hydroturbine in a WWTP in Wisconsin and evaluating the power output in addition to determining the energy savings. The WWTP considered in this study has an effluent flow rate of 190 MGD (million gallons per day) and elevation difference of 3 m (10 ft) between the final stage of treatment and the discharge point. Based on the parameters above; hubless rim-drive Kaplan type hydroturbine (RDT) is the optimal choice to be used in such an application. The RDT is designed and optimized by using in-house code. A computational fluid dynamics (CFD) software is applied to evaluate the performance of the proposed model, and the system is simulated through homer software to validate the results generated by the CFD. The expected savings is estimated to be 1564 MWh/yr.

Hydraulic transient simulation and characteristic investigation on Kaplan type hydroelectric power Plant with open channel

Kaplan type of turbines are meant for low head hydro development and sometimes are installed in systems with long open channels. Transient flow analysis in Kaplan hydroelectric power plants (HPP) is one of the most important issues for the prevention of undesirable pressure fluctuations in waterways. To keep efficient operation of a Kaplan turbine, the wicket gates and the runner blades position should be regulated as water head changed. Therefore, the hydraulic transients of Kaplan type HPP with open channel is more complex, exhibiting unique hydraulic characteristic. Based on the transient flow theory, both implicit difference method and method of characteristic are introduced to establish the mathematic model of hydraulic transients calculation for Kaplan type HPP with open channel. Then the fluid transients due to load rejection is simulated to investigate the hydraulic behaviors. The results show that different blades movements give different hydraulic behaviors. If the blades are not involved in the regulation, the hydraulic behavior is exactly the same as that of Francis turbines. If the blades adopt closure mode, the maximum spiral case pressure will slightly increase and the maximum rotating speed rising rate will obviously decrease with the increase of closing time. While the blades adopt opening mode, it will give the opposite hydraulic behavior compared to closure mode. Opening of the runner blades during the turbine shutdown can improve over-speed performance and worsen the spiral case pressure, and vice versa. Additionally, taking open channel into consideration, the influence on hydraulic characteristic is enlarged, while the length of the open channel has little effect on it.

Design of a high-specific speed turbine with non-uniform blade cascade

This paper presents the hydraulic design of Kaplan type turbine in fully axial configuration. The turbine model consists of a straight pipe intake, a rib which covers the shaft, five axial guide vanes, a six blade runner and a 10,6°-full angle draft tube. Due to the presence of non-uniform velocity field behind the rib and interaction between stator and rotor, the pressure pulsations occur and cause some excitation forces acting on the runner. To reduce these negative phenomena the six non-uniform blade runner has been designed using computational fluid dynamics modelling (CFD). The runner blades are placed in various axial distances from the guide vanes. This new design should reduce the pressure pulsations caused by interaction between the rib and the runner, which is the main negative effect by the current design. The forces and torque which are acting on the runner blades as well as the pressure inside the turbine are observed in time domain. The amplitudes and frequencies are analysed using Fast Fourier Transform (FFT). The frequencies are compared to the modal analysis results of the runner submerged in water. This hydraulic design is based on previous axial turbine, which was designed for small hydro power plant located at Lužnice River. The design point is defined by head H = 1,5 m, volumetric flow rate Q = 2,1 m3/s and RPM n = 260 min-1. This turbine was designed using six runner blades to reduce the pressure, force and torque pulsations caused mainly by wakes, which were observed behind the rib.

Effects of the Duct Angle and Propeller Location on the Hydrodynamic Characteristics of the Ducted Propeller

In the present study, the effect of the duct angle and propeller location on the hydrodynamic characteristics of the ducted propeller using Reynolds-Averaged Navier Stokes (RANS) method is reported. A Kaplan type propeller is selected with a 19A duct. The ducted propeller is analyzed by three turbulence models including the k-ε standard, k-ω SST and Reynolds stress model (RSM). The numerical results are compared with experimental data. The effects of the duct angle and the location of the propeller inside the propeller are presented and discussed.

Design of a Kaplan turbine for a wide range of operating head -Curved draft tube design and model test verification-

As for turbomachine off-design performance improvement is challenging but critical for maximising the performing area. In this paper, a curved draft tube for a medium head Kaplan type hydro turbine is introduced and discussed for its significant effect on expanding operating head range. Without adding any extra structure and working fluid for swirl destruction and damping, a carefully designed outline shape of draft tube with the selected placement of center-piers successfully supresses the growth of turbulence eddy and the transport of the swirl to the outlet. Also, more kinetic energy is recovered and the head lost is improved. Finally, the model test results are also presented. The obvious performance improvement was found in the lower net head area, where the maximum efficiency improvement was measured up to 20% without compromising the best efficiency point. Additionally, this design results in a new draft tube more compact in size and so leads to better construction and manufacturing cost performance for prototype.The draft tube geometry parameter designing process was concerning the best efficiency point together with the off-design points covering various water net heads and discharges. The hydraulic performance and flow behavior was numerically previewed and visualized by solving Reynolds-Averaged Navier-Stokes equations with Shear Stress Transport turbulence model. The simulation was under the assumption of steady-state incompressible turbulence flow inside the flow passage, and the inlet boundary condition was the carefully simulated flow pattern from the runner outlet. For confirmation, the corresponding turbine efficiency performance of the entire operating area was verified by model test.

Numerical simulation of turbulence flow in a Kaplan turbine -Evaluation on turbine performance prediction accuracy-

The understanding and accurate prediction of the flow behaviour related to cavitation and pressure fluctuation in a Kaplan turbine are important to the design work enhancing the turbine performance including the elongation of the operation life span and the improvement of turbine efficiency. In this paper, high accuracy turbine and cavitation performance prediction method based on entire flow passage for a Kaplan turbine is presented and evaluated. Two-phase flow field is predicted by solving Reynolds-Averaged Navier-Stokes equations expressed by volume of fluid method tracking the free surface and combined with Reynolds Stress model. The growth and collapse of cavitation bubbles are modelled by the modified Rayleigh-Plesset equation. The prediction accuracy is evaluated by comparing with the model test results of Ns 400 Kaplan model turbine. As a result that the experimentally measured data including turbine efficiency, cavitation performance, and pressure fluctuation are accurately predicted. Furthermore, the cavitation occurrence on the runner blade surface and the influence to the hydraulic loss of the flow passage are discussed. Evaluated prediction method for the turbine flow and performance is introduced to facilitate the future design and research works on Kaplan type turbine.

A method to combine hydrodynamics and constructive design in the optimization of the runner blades of Kaplan turbines

This paper deals with the optimization of the axial hydraulic turbines of Kaplan type. The optimization of the runner blade is presented systematically from two points of view: hydrodynamic and constructive. Combining these aspects in order to gain a safer operation when unsteady effects occur in the runner of the turbine is attempted. The design and optimization of the runner blade is performed with QTurbo3D software developed at the Center for Research in Hydraulics, Automation and Thermal Processes (CCHAPT) from "Eftimie Murgu" University of Resita, Romania. QTurbo3D software offers possibilities to design the meridian channel of hydraulic turbines design the blades and optimize the runner blade. 3D modeling and motion analysis of the runner blade operating mechanism are accomplished using SolidWorks software. The purpose of motion study is to obtain forces, torques or stresses in the runner blade operating mechanism, necessary to estimate its lifetime. This paper clearly states the importance of combining the hydrodynamics with the structural design in the optimization procedure of the runner of hydraulic turbines.

Incipient Cavitation in a Bulb Turbine: Model Test and CFD Calculation

【For a certain operating point of a horizontal shaft bulb turbine (i.e. volume flow, net head, blade angle, guide vane angle) the efficiency for different pressure levels (i.e. different Thoma-coefficient ${\sigma}$ ) is calculated using a commercial Computational Fluid Dynamics (CFD-)-code including two-phase flow and a cavitation model. The results are compared with experimental results achieved at a closed loop test rig for model turbines. The comparison of the experimentally and numerically obtained efficiency and the visual impression of the cavitation show a good agreement. Especially the drop in efficiency is calculated with satisfying accuracy. This drop in efficiency in combination with the visual impression is of high practical importance since it contributes to determine the admissible cavitation in a bulb-turbine. It is seen that the incipient cavitation in Kaplan type turbines has no major importance in determing this admissible amount of cavitation.】

Synthesis of Hexanitrostilbene (HNS) using a Kenics Static Mixer

Previous work on a Shipp−Kaplan type synthesis of hexanitrostilbene (HNS) using a Kenics static mixer (ref1, from Chemineer Ltd., Cranmer Road, West Meadows, Derby DE21 6XT, UK; www.chemineer.com) has been extended by using a larger mixer (9.5 mm vs 4.75 mm OD), enabling the scale to be increased from 2.5 g to 25 g of trinitrotoluene (TNT) for the same mixing time (<4 min). Various conditions for the after-reaction period (2 h) have been explored on the basis of previous work with a batch reactor, including (i) no pH control, (ii) pH control using aqueous H2SO4 and NaOH solutions, and (iii) pH control using aqueous RNH3Cl and RNH2 solutions. Other parameters that have been varied are the ratio of NaOCl to TNT (0.5−1.2) and the concentration of both reactants. The yields of crude HNS that have been achieved, whilst not outstanding, are an improvement over the conventional batch process. It has been demonstrated that the yield and selectivity of the HNS synthesis can be considerably increased if, during the after-reaction period, the reaction conditions are pH controlled. The yield and selectivity are also significantly enhanced by using more dilute reaction solutions.

Improvement of the efficiency of the Agnew micro hydro turbine at part loads due to installing guide vanes mechanism

Agnew turbine is an axial micro hydro of Kaplan type, with its main shaft subtending 45° to the line of horizon. Due to governmental power generating programs for limited hydro potentials in Iran and on the basis of a joint project between the University of Glasgow and the Iranian Research Organization for Science and Technology (IROST), the turbine was developed to operate under low heads and limited flow potentials in Iran. However the turbine was originally designed to operate without any guide vanes and test results showed that the turbine achieved an efficiency of 62% at its best point of performance. Later a modified Agnew turbine, consisting of a guide blades mechanism was designed and manufactured, at (IROST). The mechanism was so designed that it was also used as a second support for the turbine’s main shaft. The standard turbine tests proved that; the modified version of the Agnew turbine had 23% higher efficiency at its best performance point; compared to the original design. Then the effects of the improvements on the turbine were studied on the performance of the turbine at part loads. However, efficiency improvements were observed under all part load conditions.