scholarly journals CFD analysis of the needle tip angle in Pelton injector on jet quality for the power generation

2021 ◽  
pp. 45-59
Author(s):  
Daniel G. Taborda ◽  
Jorge Sierra-Del Rio ◽  
Juan Diego Perez-Alvarez ◽  
Arley Cardona-Vargas ◽  
Daniel Sanin Villa
Keyword(s):  
Fluid Dynamics ◽  
Power Generation ◽  
Fossil Fuels ◽  
Analysis Software ◽  
Pelton Turbine ◽  
Fluid Analysis ◽  
The Face ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Carbon Dioxide Co2

Fossil fuels are energy sources that supply a large part of the world's energy generation. However, they produce greenhouse gases such as carbon dioxide (CO2), nitrogen oxide (NOx) and particulates that increase global warming. For this reason, other forms of renewable energy such as hydropower have begun to be implemented through turbomachinery such as Pelton turbines, which significantly reduce these emissions since they are highly efficient turbines based on the use of natural resources (water). Pelton turbines are based mainly on three components for their operation, which are the Pelton injector, the bucket and the wheel. The injector is an important component in the energy transformation of Pelton turbines. Although to analyze its behavior, it is possible to use fluid dynamics (CFD) software to predict the trajectory of the flow through a solid or free surface. The objective of this work is to analyze by means of computational fluid dynamics (CFD) the incidence of the length and the needle tip angle of a Pelton turbine injector on the generated power. For this, an ANSYS 2020R2 computational fluid analysis software was used to study how the variation of the injector needle tip angle influences through the volume of fluid (VOF) method, starting from the generation of a commercial model with a tip angle of 60° and two (2) geometries of 55° and 75° respectively. Numerical results show a better performance for the 75° angle of 96 % and lower for the 55° and 60° with 94.1 % and 95.5 % respectively, whereby steeper angles achieve higher performances. In summary, the present study pretends to increase the power generation, in the face of phenomena occurred in the energy transfer. Although the performance of the injector in each angle configuration must be tested in practice

scholarly journals Investigation of Influence of Adjustments in Cyclist Arm Position on Aerodynamic Drag Using Computational Fluid Dynamics

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 159
Author(s):  
Knut Erik Teigen Giljarhus ◽  
Daniel Årrestad Stave ◽  
Luca Oggiano
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Aerodynamic Drag ◽  
Time Trial ◽  
Elbow Extension ◽  
Cfd Simulations ◽  
Arm Position ◽  
Sport Activities ◽  
The Face ◽  
Computational Fluid Dynamics Cfd

In professional cycling, even small adjustments in position could mean that valuable seconds are gained over the course of a time-trial race. This study investigates the influence of arm position on the aerodynamic drag of a cyclist. Based on a 3D scanned model of a professional cyclist, 64 alternate positions are generated. The parameters that are investigated are the distance between elbows, elbow extension, and distance between hands. Computational fluid dynamics (CFD) simulations of all positions are performed, and a regression model is built from the results. The results indicate that the optimal posture is achieved for a minimum in all investigated parameters, which means that the hands and elbows should be kept together with hands up towards the face. Furthermore, elbow extension seems to be the most crucial parameter, followed by the distance between elbows, and then by the distance between the hands. The presented methodology can be applied to study other parameters relevant to cycling aerodynamics or be applied to other sport activities as well.

scholarly journals Numerical Investigation of the Hydrodynamic Performance of the Propeller Behind the Ship with and Without Wed

2020 ◽  
Vol 27 (4) ◽  
pp. 50-59
Author(s):  
Alireza Nadery ◽  
Hassan Ghassemi
Keyword(s):  
Pressure Pulse ◽  
Wake Flow ◽  
Hydrodynamic Performance ◽  
Analysis Software ◽  
Experiment Method ◽  
The Face ◽  
Computational Fluid Dynamics Cfd ◽  
Propeller Performance ◽  
Thrust And Torque ◽  
Face Side

AbstractThe presented paper numerically carries out the investigation of the hydrodynamic performance of the propeller behind the ship with and without wake equalizing duct (WED). It is mounted in front of the propeller in order to equalize the ship’s wake flow and improve the propeller performance. The computational fluid dynamics (CFD) analysis software STAR-CCM solver was adopted to simulate the KP505 propeller behind the KRISO container ship (KCS) using overlapping grid technology and user-defined functions. To obtain the effect of a –duct on propeller performance, the ship bare hull case, the with-propeller case, and the with-propeller-and-duct case are also computed. Together, these computations provide for a –complete CFD comparison of the duct effects. Also, the Taguchi design of the experiment method is applied to investigate three parameters (angle of attack, trailing edge radius, and chord length) of the duct. Finally, the main dimensions are obtained, and the thrust and torque coefficients are presented and discussed for one blade and whole blades during one cycle. Based on the numerical results, it is indicated that good design increases efficiency by 1.67%, and a –bad design may reduce efficiency by 3.25%. Also, the effect of the WED caused to decrease the pressure pulse by 35.9% in the face side of the propeller blade.

scholarly journals Computational Analysis of High Lift Generating Airfoils for Diffuser Augmented Wind Turbines

2019 ◽  
Author(s):  
Anhad Singh Bajaj ◽  
Jayakrishnan Radhakrishnan ◽  
Raahil Nayak
Keyword(s):  
Fluid Dynamics ◽  
Computational Analysis ◽  
Aerodynamic Performance ◽  
Rotor Blades ◽  
Navier Stokes ◽  
Cfd Analysis ◽  
High Lift ◽  
Actuator Disk ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through

The present study aims to asses the aerodynamic performance of Diffuser Augmented Wind Turbine (DAWT) using high lift generating airfoils in the construction of the shroud/diffuser. The study is a Computational Fluid Dynamics (CFD) analysis which is carried out using Reynolds Averaged Navier-Stokes (RANS) simulations. The flow across the duct and rotor blades, which are modeled as an actuator disk (AD), is analyzed. Various High-Lift generating airfoils and their geometries were taken into consideration and analyzed with additional geometric modifications, such as a flange, to improve flow through the AD and increase the augmentation factor

scholarly journals Performance Evaluation of Pelton Turbine: A Review

2014 ◽  
Vol 13 ◽  
pp. 28-35 ◽  
Author(s):  
Vishal Gupta ◽  
Ruchi Khare ◽  
Vishnu Prasad
Keyword(s):  
Fluid Dynamics ◽  
Design Optimization ◽  
Performance Prediction ◽  
Hydraulic Turbine ◽  
Numerical Techniques ◽  
Pelton Turbine ◽  
Processing Power ◽  
Working Medium ◽  
Computational Fluid Dynamics Cfd

Earlier only experimental techniques were used to predict the performance of turbines. With advanced numerical techniques and increase in processing power of computers, Computational Fluid Dynamics (CFD) has emerged as an effective tool for the performance prediction of Pelton hydraulic turbine involving multi-fluid  flow. Extensive work has been done for design optimization of reaction turbines using CFD. Now it is being extended for impulse turbines. The flow in reaction turbines involves only water as working medium, but in case of impulse turbines, water and air are working medium. The water jet issued from nozzle is surrounded by air and pressure around the jet and turbine is atmospheric. The performance of Pelton turbine depends upon the shape, size and quality of jet as well as shape of the buckets. In the present paper, the literature review on applications of CFD for performance prediction, design optimization of Pelton turbine have been discussed.DOI: http://dx.doi.org/10.3126/hn.v13i0.10042HYDRO NEPAL Journal of Water, Energy and EnvironmentIssue No. 13, July 2013Page: 28-35Uploaded date: 3/13/2014

Flow Field Simulation and Atomization Characteristic of Pneumatic Oil Mist Swirler

2011 ◽  
Vol 339 ◽  
pp. 400-405
Author(s):  
Xiao Ming Yang ◽  
Jian Wen Chen ◽  
Lei Li ◽  
Jin Jin Liu ◽  
Yu Long Zhao
Keyword(s):  
Fluid Dynamics ◽  
Particle Size ◽  
Flow Field ◽  
Compressed Air ◽  
Analysis Software ◽  
Flow Field Simulation ◽  
Fluid Analysis ◽  
Field Simulation ◽  
Oil Mist ◽  
Good Agreement

Based on the theory of Fluid Dynamics CFD and Fluid analysis software Fluent，we accomplished the flow field simulation of internal speed and internal pressure of pneumatic oil mist atomizer. Both the flow field simulation and the results of experiment are in good agreement，particle size and density of oil mist change very little when the pressure of compressed air is kept constant while the distance of nozzle and baffle is varied. When the distance from nozzle to baffle is fixed, and the pressure of compressed air is increased gradually, the density of oil mist will increase and the particle size of oil mist will decrease along with the increasing pressure of compressed air. This decreasing trend of particle size of oil mist will slow down when the pressure of compressed air increases to 0.35Mpa. The particle size of oil mist can reach 2μm.

Swirling Flow Through Venturi Tubes of Convergent Angle 10.5° and 21°

2006 ◽  
Author(s):  
Jeff Gibson ◽  
Michael Reader-Harris
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Reynolds Number ◽  
Swirling Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Good Agreement

Computational Fluid Dynamics (CFD) was used to compute the effect of two bends in perpendicular planes on the performance of 4-inch Venturi tubes with β = 0.4, 0.6 and 0.75 for water at a Reynolds number of 350,000 and at various distances from the bend. Two types of Venturi tubes were analysed, the first having a standard convergent angle of 21°, the second having a non-standard convergent angle of 10.5°. Good agreement with experiment was obtained. Swirling axisymmetric flows were computed to help interpret experimental data.

Modelling the flow distribution through automotive catalytic converters

2001 ◽  
Vol 215 (4) ◽  
pp. 379-383 ◽  
Author(s):  
S F Benjamin ◽  
N Haimad ◽  
C A Roberts ◽  
J Wollin
Keyword(s):  
Fluid Dynamics ◽  
Flow Distribution ◽  
Maximum Flow ◽  
One Dimensional ◽  
Exhaust Catalysts ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Automotive Catalytic Converters ◽  
Flow Maldistribution ◽  
Maximum Flow Velocity

Conventional computational fluid dynamics (CFD) methods for simulating the flow through automotive exhaust catalysts assume a monolith resistance based on one-dimensional laminar flow. This underpredicts the flow maldistribution in the monolith. Incorporation of an additional pressure loss accounting for entrance effects improves predictions for the maximum flow velocity within the substrate.

scholarly journals Comparison of the heat for rectangular and circle salt boiling stove in Ban Dung area, Udon Thani Province.

2018 ◽  
Vol 192 ◽  
pp. 02031
Author(s):  
Aphichat Srichat ◽  
Ponthep Vengsungnle ◽  
Kaweepongt Hongtong ◽  
Weeraphon Kaewka ◽  
Jarinee Jongpluempiti
Keyword(s):  
Fluid Dynamics ◽  
Thermal Efficiency ◽  
Thermal Parameter ◽  
Sectional Area ◽  
Cross Sectional ◽  
Hot Air ◽  
Boiling Process ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
The Cost

This research aims a study to compare the thermal parameter of the original (rectangular) and circle salt boiling stove by computational fluid dynamics (CFD) of the boiling salt process in Ban Dung area, Udon Thani province. The first study, the rectangular stove has U-shaped channel for heating flow through chimney that the stove size is 2.4 m of width, 6.0 m of long, 0.8 m of high and cross-sectional area of heating flue was 0.8 x 0.8 m2. The second study, the circle salt boiling stove has a similarly volume of the rectangular stove of 4.32 m3 and the diameter of 4.58 m. From the results of mathematical models by CFD found that the rectangular stove have the thermal efficiency, the highest fired temperature and the velocity outlet of hot air of 17.78%, 537.77oC and 4.862 m/s, respectively. Then, the circle stove have 24.59%, 758.32oC and 3.1424 m/s, respectively. it can be calculated the thermal efficiency reduce of the boiling salt production is 27.69%. Comparison between the rectangular and the circle salt boiling stove found that the circle stove have the thermal efficiency and heating flue more than the rectangular stove. It can reduce the cost of production and reduce the fuel consumption in the salt boiling process.

CFD Simulation for Reduction of Oil Churning Loss and Windage Loss on Aeroengine Transmission Gears

2009 ◽  
Author(s):  
Hidenori Arisawa ◽  
Motohiko Nishimura ◽  
Hideyuki Imai ◽  
Tatsuhiko Goi
Keyword(s):  
Fluid Dynamics ◽  
Power Generation ◽  
Cfd Simulation ◽  
Spur Gears ◽  
Power Losses ◽  
Air Conditioners ◽  
Bevel Gears ◽  
Civil Aircraft ◽  
Generation Capacity ◽  
Computational Fluid Dynamics Cfd

In recent years, the demand for power generation capacity has increased considerably due to the electric drive of air conditioners and so on in the engines of civil aircraft. Therefore, it is estimated that power losses may increase in the gearbox because of generators and pumps that in turn augment fuel consumption. To understand the phenomena of losses in the gearbox and to reduce these losses, Computational Fluid Dynamics (CFD) simulation that analyzes oil churning loss and windage loss was developed and improvements were made to the shroud of bevel gears. The CFD agreed with experimental results on a bevel gearbox of a 100-seater aircraft. And, it was shown that the suppression of momentum transfer from the rotating gears to oil clusters is of importance. In addition, it was revealed that the loss was reduced up to 36% compared to non-shrouded gears by shrouding in the experiments. This CFD simulation can be applied to many types of gearboxes that have spur gears, bearings and seals.

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