scholarly journals Feasibility study of power generation using a turbine mounted in aircraft wing

2018 ◽  
Vol 7 (2-1) ◽  
pp. 433
Author(s):  
K. Sri Vamsi Krishna ◽  
Shiva Prasad ◽  
R. Sabari Vihar ◽  
K. Babitha ◽  
K Veeranjaneyulu ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Power Systems ◽  
Free Stream ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Aircraft Wing ◽  
Aerodynamic Efficiency ◽  
Turbulent Reynolds Number ◽  
Main Motive ◽  
Emergency Power

The main objective of this study is to increase the aerodynamic efficiency of turbine mounted novel wing. The main motive behind this work is to reduce the drag by attaining the positive velocity gradient and generate power by converting the stagnation pressure which also acts as emergency power source. By using the energy source of free stream air, Mechanical energy is converted into electrical energy. The obtained power is presented in terms of voltage generated at various angles of attack with different Reynolds number. Experimental analysis is carried out for NACA4415 airfoil at various angles with respect to free stream ranging from 0deg to 30deg from laminar to turbulent Reynolds number. The results were obtained using the research tunnel at IARE aerodynamic facility center. The aerodynamic advantage of this design in terms of voltage is 9.5 V at 35m/s which can be utilized for the aircraft on board power systems.

scholarly journals Effect of free-stream turbulence and other vortical disturbances on a laminar boundary layer

1999 ◽  
Vol 380 ◽  
pp. 169-203 ◽  
Author(s):  
S. J. LEIB ◽  
DAVID W. WUNDROW ◽  
M. E. GOLDSTEIN
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Free Stream ◽  
Stokes Equations ◽  
Plate Boundary ◽  
Streamwise Velocity ◽  
Boundary Region ◽  
Quantitative Agreement ◽  
Free Stream Turbulence ◽  
Turbulent Reynolds Number

This paper is concerned with the effect of free-stream turbulence on the pretransitional flat-plate boundary layer. It is assumed that either the turbulent Reynolds number or the downstream distance (or both) is small enough that the flow can be linearized. The dominant disturbances in the boundary layer, which are of the Klebanoff type, are governed by the linearized unsteady boundary-region equations, i.e. the linearized Navier–Stokes equations with the streamwise derivatives neglected in the viscous and pressure-gradient terms. The turbulence is represented as a superposition of vortical free-stream Fourier modes and the corresponding Fourier component solutions to the boundary-region equations are obtained numerically. The results are then superposed to compute the root mean square of the fluctuating streamwise velocity in the boundary layer produced by the actual free-stream turbulence. It is found that the disturbances computed with isotropic free-stream turbulence do not reach the levels measured in experiments. However, good quantitative agreement is obtained with the relatively low turbulent Reynolds number data of Kendall when the measured strong anisotropy of the low-frequency portion of his spectrum is accounted for. Data at higher turbulent Reynolds numbers are affected by nonlinearity, which manifests itself through the generation of small spanwise length scales. We attempt to model this within the context of the linear theory by choosing a free-stream spectrum whose energy is concentrated at larger transverse wavenumbers and achieve very good agreement with the data. The results suggest that even small deviations from pure isotropy can be an important factor in explaining the large amplitudes of the Klebanoff modes in the pre-transitional boundary layer, and also point to the importance of nonlinear effects. We discuss some additional effects that may need to be accounted for in order to obtain a complete description of the Klebanoff modes.

scholarly journals UTILIZATION OF MAXIMUM POWER IN AIRFOIL BLADE OF HORIZONTAL AXIS WIND TURBINE BY THE CONCEPT OF CFD ANALYSIS

2019 ◽  
pp. 266-273
Author(s):  
Abhishek Choubey
Keyword(s):  
Power Systems ◽  
Wind Turbine ◽  
Wind Power ◽  
Mechanical Energy ◽  
Energy Resource ◽  
Electrical Energy ◽  
Maintenance Cost ◽  
Cfd Analysis ◽  
Horizontal Axis Wind Turbine ◽  
Power Generators

Pollution free power production, quick installation and commissioning capability, less operation and maintenance cost and taking benefit of by means of free and renewable energies are all advantages of using wind turbines as an power generators. Along with these advantages, the main drawback of this source is the conditional nature of wind flow. Therefore, using reliable and efficient apparatus is necessary in order to get as much as energy from wind during the limited period of time that it flows strongly. Wind power is the fastest increasing renewable energy resource and wind power penetration in power systems increases at a significant rate. The high access of wind power into power systems in the present and near future will have several impacts on their planning and operation. A wind turbine transforms the kinetic energy in the wind to mechanical energy in a shaft and ultimately into electrical energy in a generator. Turbine blade is the mainly important part of any wind turbine. In this paper we consider single airfoil NACA 0018 and done CFD analysis at different blade angles 00,100,150 and 300 with constant wind velocity of 6 m/s. The analysis results show that blade angle 15º gives best possible power.

scholarly journals Investigation on airfoil operating in Ground Effect region

2014 ◽  
Vol 3 (4) ◽  
pp. 540 ◽  
Author(s):  
Nikhil Pillai ◽  
Anil T. ◽  
Aravind Radhakrishnan ◽  
Rahul Vinod ◽  
Sudheesh Kumar E. ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Advisory Committee ◽  
Special Class ◽  
Free Stream ◽  
Angle Of Attack ◽  
Ground Effect ◽  
Water Bodies ◽  
Cfd Analysis ◽  
Aerodynamic Efficiency ◽  
Wing In Ground Effect

The idea of using a wing in ground effect vehicle has been suggested with the objective of developing a very economical and efficient means of rapid transportation across water bodies. This paper investigates into wing in ground effect airfoil geometry. ANSYS is used to perform the CFD analysis of the airfoils. CFD analysis has been performed on various airfoils operating in the ground effect region and a special class of airfoil called DHMTU has been found to have maximum aerodynamic efficiency. The DHMTU studied here is DHMTU 8-40-2-10-3-6-2-15. Aerodynamic efficiency for this particular airfoil has been determined through CFD analysis at various angles of attack. It has been found that the DHMTU possesses superior aerodynamic efficiency at low angle of attack and the maximum aerodynamic efficiency is found at 60 angle of attack. From CFD analysis it has also been determined that as the proximity to the ground reduces, the value of lift increases. The characteristics of this airfoil at various air speeds have also been determined through CFD analysis. These studies have illustrated the unique characteristics of the DHMTU airfoils and indicated areas for further optimization of the design of ground effect airfoils. The use of this airfoil for the ground effect vehicle can further lead to increase in efficiency of the craft.Abbreviations:CFD                        Computational Fluid DynamicsDHMTU                Department Of Hydro-Mechanics of the Marine Technical UniversityNACA                    National Advisory Committee on AeronauticsL/D                         Lift to Drag RatioWIG                       Wing in GroundV                             Free stream velocityRe                           Reynolds number h/c                          Height to Chord RatioCL                          Coefficient of liftCD                          Coefficient of dragAOA                       Angle Of Attack

Reduction of structural vibrations with the piezoelectric stacks ring

2020 ◽  
Vol 64 (1-4) ◽  
pp. 729-736
Author(s):  
Jincheng He ◽  
Xing Tan ◽  
Wang Tao ◽  
Xinhai Wu ◽  
Huan He ◽  
...  
Keyword(s):  
Vibration Control ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Structural Vibrations ◽  
Rotor Systems ◽  
Fea Model ◽  
Piezoelectric Stacks ◽  
Shunt Damping ◽  
Reduction Effect ◽  
Euler Bernoulli Beam

It is known that piezoelectric material shunted with external circuits can convert mechanical energy to electrical energy, which is so called piezoelectric shunt damping technology. In this paper, a piezoelectric stacks ring (PSR) is designed for vibration control of beams and rotor systems. A relative simple electromechanical model of an Euler Bernoulli beam supported by two piezoelectric stacks shunted with resonant RL circuits is established. The equation of motion of such simplified system has been derived using Hamilton’s principle. A more realistic FEA model is developed. The numerical analysis is carried out using COMSOL® and the simulation results show a significant reduction of vibration amplitude at the specific natural frequencies. Using finite element method, the influence of circuit parameters on lateral vibration control is discussed. A preliminary experiment of a prototype PSR verifies the PSR’s vibration reduction effect.

scholarly journals Effects of Turbulent Reynolds Number on the Performance of Algebraic Flame Surface Density Models for Large Eddy Simulation in the Thin Reaction Zones Regime: A Direct Numerical Simulation Analysis

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Mohit Katragadda ◽  
Nilanjan Chakraborty ◽  
R. S. Cant
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Fractal Dimension ◽  
Direct Numerical Simulation ◽  
Surface Density ◽  
Flame Surface ◽  
Algebraic Models ◽  
Flame Surface Density ◽  
Turbulent Reynolds Number ◽  
Reaction Zones

A direct numerical simulation (DNS) database of freely propagating statistically planar turbulent premixed flames with a range of different turbulent Reynolds numbers has been used to assess the performance of algebraic flame surface density (FSD) models based on a fractal representation of the flame wrinkling factor. The turbulent Reynolds number Rethas been varied by modifying the Karlovitz number Ka and the Damköhler number Da independently of each other in such a way that the flames remain within the thin reaction zones regime. It has been found that the turbulent Reynolds number and the Karlovitz number both have a significant influence on the fractal dimension, which is found to increase with increasing Retand Ka before reaching an asymptotic value for large values of Retand Ka. A parameterisation of the fractal dimension is presented in which the effects of the Reynolds and the Karlovitz numbers are explicitly taken into account. By contrast, the inner cut-off scale normalised by the Zel’dovich flame thicknessηi/δzdoes not exhibit any significant dependence on Retfor the cases considered here. The performance of several algebraic FSD models has been assessed based on various criteria. Most of the algebraic models show a deterioration in performance with increasing the LES filter width.

Free-stream coherent structures in parallel boundary-layer flows

2014 ◽  
Vol 752 ◽  
pp. 602-625 ◽  
Author(s):  
Kengo Deguchi ◽  
Philip Hall
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Coherent Structures ◽  
Free Stream ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Homotopy Continuation ◽  
Boundary Layer Flows ◽  
Navier Stokes Equations ◽  
High Reynolds

AbstractOur concern in this paper is with high-Reynolds-number nonlinear equilibrium solutions of the Navier–Stokes equations for boundary-layer flows. Here we consider the asymptotic suction boundary layer (ASBL) which we take as a prototype parallel boundary layer. Solutions of the equations of motion are obtained using a homotopy continuation from two known types of solutions for plane Couette flow. At high Reynolds numbers, it is shown that the first type of solution takes the form of a vortex–wave interaction (VWI) state, see Hall & Smith (J. Fluid Mech., vol. 227, 1991, pp. 641–666), and is located in the main part of the boundary layer. On the other hand, here the second type is found to support an equilibrium solution of the unit-Reynolds-number Navier–Stokes equations in a layer located a distance of $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}O(\ln \mathit{Re})$ from the wall. Here $\mathit{Re}$ is the Reynolds number based on the free-stream speed and the unperturbed boundary-layer thickness. The streaky field produced by the interaction grows exponentially below the layer and takes its maximum size within the unperturbed boundary layer. The results suggest the possibility of two distinct types of streaky coherent structures existing, possibly simultaneously, in disturbed boundary layers.

Direct numerical simulation of flow past a transversely rotating sphere up to a Reynolds number of 300 in compressible flow

2018 ◽  
Vol 857 ◽  
pp. 878-906 ◽  
Author(s):  
T. Nagata ◽  
T. Nonomura ◽  
S. Takahashi ◽  
Y. Mizuno ◽  
K. Fukuda
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Mach Number ◽  
Direct Numerical Simulation ◽  
Drag Coefficient ◽  
Rotation Rate ◽  
Free Stream ◽  
Rotating Sphere ◽  
Free Stream Mach Number ◽  
Low Reynolds

In this study, direct numerical simulation of the flow around a rotating sphere at high Mach and low Reynolds numbers is conducted to investigate the effects of rotation rate and Mach number upon aerodynamic force coefficients and wake structures. The simulation is carried out by solving the three-dimensional compressible Navier–Stokes equations. A free-stream Reynolds number (based on the free-stream velocity, density and viscosity coefficient and the diameter of the sphere) is set to be between 100 and 300, the free-stream Mach number is set to be between 0.2 and 2.0, and the dimensionless rotation rate defined by the ratio of the free-stream and surface velocities above the equator is set between 0.0 and 1.0. Thus, we have clarified the following points: (1) as free-stream Mach number increased, the increment of the lift coefficient due to rotation was reduced; (2) under subsonic conditions, the drag coefficient increased with increase of the rotation rate, whereas under supersonic conditions, the increment of the drag coefficient was reduced with increasing Mach number; and (3) the mode of the wake structure becomes low-Reynolds-number-like as the Mach number is increased.

scholarly journals Analisis Pembangkit Listrik Berbasis Flywheel

2019 ◽  
Vol 17 (1) ◽  
pp. 95
Author(s):  
Jumadi Tangko ◽  
Remigius Tandioga ◽  
Ismail Djufri ◽  
Riza Haardiyanti
Keyword(s):  
Power Plant ◽  
Rotational Speed ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Moment Of Inertia ◽  
Mechanical Device ◽  
Load Bearing ◽  
Wheeled Vehicles ◽  
Load Conditions

Flywheel is a rotating mechanical device, which is generally used on four-wheeled vehicles. Flywheel has a moment of inertia that is able to withstand changes in rotational speed. The energy in flywheel is mechanical energy. This mechanical energy will be converted by generators into electrical energy. At the flywheel-based power plant, tests are carried out in the form of rotation, the generator power of the generator under no load or load conditions, and the time needed for this generator to survive. The results showed that the ability of the flywheel-based power plant in the condition without a backup supply to the motor in the condition of a generator without a load is able to generate power of 860.1 W for 22 seconds, while in a load-bearing generator capable of generating electricity by 708.75 W for 18 seconds 

scholarly journals Triboelectric nanogenerators (TENG): Factors affecting its efficiency and applications

2021 ◽  
Vol 34 (2) ◽  
pp. 157-172
Author(s):  
Deepak Anand ◽  
Singh Sambyal ◽  
Rakesh Vaid
Keyword(s):  
Large Scale ◽  
Review Paper ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Wearable Electronics ◽  
Factors Affecting ◽  
Electrostatic Induction ◽  
Triboelectric Nanogenerators ◽  
Human Motions ◽  
Great Scope

The demand for energy is increasing tremendously with modernization of the technology and requires new sources of renewable energy. The triboelectric nanogenerators (TENG) are capable of harvesting ambient energy and converting it into electricity with the process of triboelectrification and electrostatic-induction. TENG can convert mechanical energy available in the form of vibrations, rotation, wind and human motions etc., into electrical energy there by developing a great scope for scavenging large scale energy. In this review paper, we have discussed various modes of operation of TENG along with the various factors contributing towards its efficiency and applications in wearable electronics.

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