scholarly journals Aerodynamic Performance Characterization of Slotted Propeller: Part B Effect of Angle

2019 ◽  
Vol 11 (4) ◽  
pp. 155-170
Author(s):  
Aravind SEENI
Keyword(s):  
Rotational Speed ◽  
Aerodynamic Performance ◽  
Von Mises Stress ◽  
Power Coefficient ◽  
Small Scale ◽  
Propeller Blade ◽  
Static Structure ◽  
Thrust Coefficient ◽  
Advance Ratio ◽  
Von Mises

In this paper, designs of slotted propeller blade were discussed numerically, in terms of aerodynamic performance and static structural analysis. Baseline APC Slow Flyer 10’ x 7’ small scale propeller blade was modified by including slots along the propeller blade. Numerical analysis has been done to determine the influence of slots angle towards thrust coefficient, power coefficient and efficiency. Simulations were performed by using ANSYS Fluent implementing k-ω turbulence model and Multiple Reference Frame to incorporate rotational speed of the propeller. The analyses were conducted at a fixed rotational speed, with variance of advance ratio. Initial slotted design is set at 180 degree and the angles were changed with 10-degree interval, ranging from 180 degree to 90 degree. The results were compared with available experimental data. For the slotted design, the result shows that inducing slots do not always lead to improvement in propeller blade performance. Improvement in thrust coefficient with the range of 0.267% to 2.71% can be seen for low advance ratio for most of slot angles. However, a significant increase in power coefficient can be observed which reduces the overall efficiency of the propeller blade. For stress and deformation, ANSYS Mechanical Static Structure was used to determine maximum Von-Mises stress, maximum Von-Mises strain, and total deformation. The analyses were conducted by using 60% long strand fiber glass reinforced nylon 6 Natural. The blade is more suitable to operate at higher velocity. At lower operational velocity, the blade tends to experience material failure as the stress exceeds stress at break.

scholarly journals Aerodynamic Performance Characterization and Structural Analysis of Slotted Propeller: Part A Effect of Position

2020 ◽  
Vol 12 (2) ◽  
pp. 183-198
Author(s):  
Aravind SEENI
Keyword(s):  
Pressure Distribution ◽  
Structural Integrity ◽  
Power Coefficient ◽  
Propeller Blade ◽  
Ansys Fluent ◽  
Thrust Coefficient ◽  
Baseline Design ◽  
Propeller Design ◽  
Advance Ratio ◽  
C 50

Novel slotted propeller design performance is presented in terms of thrust coefficient, power coefficient and efficiency by utilizing ANSYS Fluent. The effects of slotted positions were discussed with respect to baseline APC Slow Flyer 10’ x 7’ configurations. Seven slot locations with respect to chord length(c) namely 12.5%c, 25%c, 37.5%c, 50%c, 62.5%c, 75%c and 87.5%c were tested. The result shows that introduction of slot along the propeller blade increases the thrust coefficient, in the range of 0.1% to 4.74% for low advance ratios. However, increase in thrust coefficient also increases power coefficient compared to baseline design, hence reducing propeller efficiency. In addition, structural integrity of the blade was tested. The pressure distribution of the propeller blade demonstrated higher pressure on the back section, and lower pressure at the front section which results in thrust. In addition, the result shows that the pressure distribution is highly influenced by changes in advance ratio. The analysis shows that the novel propeller design managed to withstand stress and strain breaking point when operated at high advance ratio.

Aerodynamic performance of a small-scale tilt rotor: Numerical simulation and experiment in steady state

2020 ◽  
pp. 095440622095035
Author(s):  
Haitao Yang ◽  
Wei Xia ◽  
Kun Wang ◽  
Shuling Hu
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Wind Tunnel ◽  
Tilt Angle ◽  
High Speed ◽  
Aerodynamic Performance ◽  
Small Scale ◽  
Thrust Coefficient ◽  
Wind Tunnel Tests ◽  
Advance Ratio

The present work studies the aerodynamic performance of a small-scale rotor in tilting transition states through wind tunnel tests and numerical simulations. Firstly, the test platform for the rotor aerodynamics is built up, and the Computational Fluid Dynamics (CFD) model of flow field around the rotors is established based on the multiple reference frame method. Secondly, the effects of flow velocity, tilt angle and advance ratio on the aerodynamic performance of the rotor are investigated using both the numerical simulation and the wind tunnel test. It is found that for the Model 8038 rotor with maximum effeciency of 0.567 at advance ratio of 0.43, the rotor thrust coefficient increases with the increase of the Reynolds number. At Reynolds number of 410 thousand to 820 thousand, the thrust coefficient increases slightly with the increase of the rotating speed. The results also show that the thrust coefficient decreases with the increase of the advance ratio. With high-speed airflow and relatively low-speed rotation, “windmill” phenomenon is found in the experiment. The tilting of the rotor from level flight to hovering increases the thrust coefficient. Highly dependency of the tilt angle on the thrust coefficients at given advance ratios is found in the wind tunnel tests.

scholarly journals Effect of Rotor Spacing and Duct Diffusion Angle on the Aerodynamic Performances of a Counter-Rotating Ducted Fan in Hover Mode

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1338
Author(s):  
Woo-Yul Kim ◽  
Santhosh Senguttuvan ◽  
Sung-Min Kim
Keyword(s):  
Steady State ◽  
Numerical Model ◽  
Figure Of Merit ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Flow Conditions ◽  
Thrust Coefficient ◽  
Ducted Fan ◽  
Aerodynamic Performances ◽  
Rotor Model

The aerodynamic performance of a counter-rotating ducted fan in hover mode is numerically analyzed for different rotor spacings and duct diffusion angles. The design of the counter-rotating fan is inspired by a custom-designed single rotor ducted fan used in a previous study. The numerical model to predict the aerodynamic performance of the counter-rotating ducted fan is developed by adopting the frozen rotor approach for steady-state incompressible flow conditions. The relative angle between the front and the rear rotor is examined due to the usage of the frozen rotor model. The results show that the variation of thrust for the different relative angles is extremely low. The aerodynamic performances are evaluated by comparing the thrust, thrust coefficient, power coefficient, and figure of merit (FOM). The thrust, thrust coefficient, and FOM slightly increase with increasing rotor spacing up to 200 mm, regardless of the duct diffusion angle, and reduce on further increase in the rotor spacing. The duct diffusion angle of 0° generates about 9% higher thrust and increases the FOM by 6.7%, compared with the 6° duct diffusion angle. The duct diffusion angle is highly effective in improving the thrust and FOM of the counter-rotating ducted fan, rather than the rotor spacing.

Simulation Using Finite Element Analysis in the Optimization of Inflatable Bedpan Wall Thickness

2015 ◽  
Vol 754-755 ◽  
pp. 747-751
Author(s):  
M. Hakim Ibrahim ◽  
S. Shahnaz S. Bakar ◽  
Luqman Musa ◽  
S. Yahud ◽  
S. Zaharah Ahmad ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Static Analysis ◽  
Polyvinyl Chloride ◽  
Structure Analysis ◽  
Cross Section ◽  
Von Mises Stress ◽  
Static Structure ◽  
Element Analysis ◽  
Von Mises

The inflatable bedpan is designed to provide comfortable, convenient, safe, hygienic, efficient and easy to use to the patients and their caretakers. In order to investigate the suitability thickness of inflatable bedpan for the pressure inflow in bedpan tube, the analysis is done using Catia analysis. The static analysis work is carried out to inflatable bedpan cross section of polyvinyl chloride (PVC) and their relative performances have been observed respectively. The thickness 0.5 mm shows the highest Von Mises Stress which is 21100 kPa compared to 0.8and 1.0 mm thicknesses. The lowest Von Mises Stress observed at thickness 1.0 mm which is 2990 kPa. The less stress obtained can encourage perfect shape of the design. In this paper, by observing the result of static structure analysis obtained, 1 mm is suggested as best thickness to be used as an inflatable bedpan wall because it can withstand more pressure while maintaining its stability.

scholarly journals Numerical analysis on the performance of Dual Rotor wind turbine

2020 ◽  
Vol 8 (03) ◽  
pp. 352-368
Author(s):  
Hazem Ali Abdel Karim ◽  
Ahmed Reda El-Baz ◽  
Nabil Abdel Aziz Mahmoud ◽  
Ashraf Mostafa Hamed
Keyword(s):  
Wind Turbine ◽  
Rotational Speed ◽  
Pitch Angle ◽  
Numerical Study ◽  
Three Dimensional ◽  
Scale Model ◽  
Power Coefficient ◽  
Peak Performance ◽  
Small Scale ◽  
Cfd Simulations

This study investigates the aerodynamic performance of wind turbines aiming to maximize the power extracted from the wind. The study is focusing on the effect of introducing a second rotor to the main rotor of the wind turbine in what is called a dual rotor wind turbine (DRWT).  The numerical study took place on the performance of small-scale model of wind turbine of 0.9 m diameter using S826 airfoil. Both the Co-rotating and Counter rotating configurations were investigated at different tip speed ratios (TSR) and compared with the performance of the single rotor wind turbine (SRWT). Many parameters were studied for dual rotor turbines. These include the spacing between the two rotors, the pitch angle of the rear rotor and the rotational speed of ratio rear to front rotor. Three-dimensional simulations performed and employed using CFD simulations with Multi Reference Frame (MRF) technique. The Co Rotating Wind Turbine (CWT) and Counter Rotating Wind Turbine (CRWT) found to have better performance compared to that of the SRWT with an increase ranging from 12 to 14% in peak power coefficient. Moreover, the effect of changing the pitch angle of the rear rotor on the overall performance found to be of a negligible effect between angles 0⁰ until 2⁰ degrees tilting toward the front rotor. On the other hand, the ratio of rotational speed of the rear rotor to the front rotor found to cause a further increase in the peak performance of the CWT and CRWT ranging from 3 to 5%.

Computational fluid dynamics study of Savonius rotors using OpenFOAM

2020 ◽  
pp. 0309524X2092495
Author(s):  
Federico González Madina ◽  
Alejandro Gutiérrez ◽  
Pedro Galione
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
Dynamics Simulation ◽  
Power Coefficient ◽  
Small Scale ◽  
Two Dimensional ◽  
Discretization Schemes ◽  
Set Up

In this work, two-dimensional models of Savonius rotors are simulated using OpenFOAM® in order to predict the aerodynamic performance of small-scale vertical-axis wind turbines. The results are reported analyzing the aerodynamic performance and forces acting on the rotors. Power coefficient, [Formula: see text], is compared with experimental data for each operation point, and for three different geometries. Simulations with first- and second-order discretization schemes are carried out and compared, both quantitative and qualitative. Since usual grid dimensions result not to be suitable for simulations of Savonius rotors, an analysis of different domains is performed and compared. Finally, a set up for computational fluid dynamics simulation of two-dimensional Savonius rotors is proposed. The fluid–rotor interaction is analyzed and the vortex shedding is correlated with [Formula: see text] values and wake description.

scholarly journals Low Reynolds Number Scaling Eeffects For Small-Scale Rotors

2021 ◽  
Author(s):  
Ammar Jessa
Keyword(s):  
Reynolds Number ◽  
Scaling Laws ◽  
Full Range ◽  
Reynolds Numbers ◽  
Power Coefficient ◽  
Small Scale ◽  
Force Coefficient ◽  
Thrust Coefficient ◽  
Rolling Moment ◽  
Moment Coefficient

<div>Three T-Motor rotors with different diameters but otherwise identical relative geometries were tested in fully edgewise flow at different advance ratios and Reynolds numbers. The objective was to verify whether the existing scaling relationships between rotor size and the aerodynamic forces are applicable to small scale rotors that operate at relatively low chord-Reynolds numbers. The rotors were mounted onto a test stand housed inside a closed loop wind-tunnel where the air speed of the tunnel was varied to achieve different advance ratios. The chord-Reynolds umber at 75% of the radius of each blade were matched for ranges from 39,000 to 117,000. The experimental data was also compared to computational results from a blade element momentum theory-based method. The results showed that the existing coefficient based scaling laws can be used to predict the performance parameters for the thrust coefficient, power coefficient, longitudinal force coefficient, side force coefficient and, rolling moment coefficient for the full range of Reynolds numbers tested. Although for the pitching moment coefficient, a coefficient approach became less applicable for chord-Reynolds number of less than 100,000.</div>

scholarly journals Optimization of aerodynamic performance for co-axial rotors with different rotor spacings

2018 ◽  
Vol 10 (4) ◽  
pp. 362-369
Author(s):  
Yao Lei ◽  
Yuxia Ji ◽  
Changwei Wang
Keyword(s):  
Power Consumption ◽  
Aerodynamic Performance ◽  
Separation Distance ◽  
Power Coefficient ◽  
Axial Thrust ◽  
Thrust Coefficient ◽  
Hover Performance ◽  
Power Loading ◽  
Blade Tip ◽  
Aerodynamic Interference

In this article, attempts are made to study the aerodynamic performance of co-axial rotors with different rotor spacings in hover. A custom-designed experimental platform with seven rotor spacings ( z/D = 0.16, 0.19, 0.23, 0.26, 0.29, 0.33 and 0.38) is applied to measure the hover performance, i.e. co-axial thrust and power consumption, and to optimize the aerodynamic configuration of the co-axial system. The experimental errors in thrust coefficient, power coefficient and power loading calculated through ‘Kline-McClintock equation’ are less than 2%. Additionally, the streamline distribution and pressure of blade tip at different rotor spacings obtained from numerical simulations are presented to visualize the effects of aerodynamic interference between the top and bottom rotor. Results show that the aerodynamic performance of a co-axial rotor with the specific rotor configure and speed range can be indeed improved by changing the rotor spacing, and the optimal performance is obtained with a rotor spacing of 0.19. Also, the magnitude of aerodynamic interference related to the axial separation distance has demonstrated to be beneficial on the total thrust and power consumption. For the same disc loading, a decrease in rotational speed results in an increase in power loading especially for z/D = 0.19. It is also found that the bottom rotor does affect the performance of the top rotor at smaller rotor spacings, whereas the effect is significantly reduced as the rotor spacing increases.

scholarly journals A CFD Simulation on the Performance of Slotted Propeller Design for Various Airfoil Configurations

CFD letters ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 43-57
Author(s):  
Wan Mazlina Wan Mohamed ◽  
Nirresh Prabu Ravindran ◽  
Parvathy Rajendran
Keyword(s):  
Reynolds Number ◽  
Power Efficiency ◽  
High Reynolds Number ◽  
Power Coefficient ◽  
Small Scale ◽  
Power Ratio ◽  
Thrust Coefficient ◽  
High Lift ◽  
Propeller Design ◽  
High Reynolds

The usage of slots has gained renewed interest in aerospace, particularly on propeller design. Most of the works have focused on improving the aerodynamic performance and efficiency. Modern research on propeller design aims to design propellers with high thrust performance under low torque conditions without any weight penalty. Although research on slotted design has been done before, none has been done to understand its impact on different airfoils on the propeller blade. Thus, this study aims to provide extensive research on slotted propeller design with various airfoil of different properties such as high Reynolds number, low Reynolds number, symmetrical, asymmetrical high lift, and low drag. This work has been investigated using computational fluid dynamics method to predict propeller performance for a small-scale propeller. The slotted blade designs' performance is presented in terms of thrust coefficient, power coefficient, efficiency, and thrust to power ratio. Here, the slotted APC Slow Flyer propeller blade's performance has been investigated for diverse types of airfoils with the shape and position of the slot is fixed which is a square-shaped at 62.5% of the chord length. The flow simulations are performed through three-dimensional computational fluid dynamic software (ANSYS Fluent) to determine the thrust coefficient, power coefficient, efficiency, and thrust to power ratio measured in advancing flow conditions. Findings show that the slotted propeller design composed of symmetrical, high Reynolds number, high lift airfoils can benefit the most with slots' implementation. These improvements were 19.49%, 69.13%, 53.57% and 111.06% in terms of thrust, power, efficiency and trust to power ratio respectively.

scholarly journals Experimental and computational investigation of energy ball wind turbine aerodynamic performance

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401987954
Author(s):  
Engy Elshazly ◽  
Nabil Eltayeb ◽  
Amr A Abdel Fatah ◽  
Tamer Ahmed El-Sayed
Keyword(s):  
Wind Turbine ◽  
Twist Angle ◽  
Flow Simulation ◽  
Aerodynamic Performance ◽  
Physical Models ◽  
Coefficient Of Performance ◽  
Power Coefficient ◽  
Small Scale ◽  
Venturi Effect ◽  
Energy Ball

Small-scale wind turbines with innovative design are introduced for small applications, providing clean renewable energy to rural homes, street lighting, and hybrid systems. Energy ball wind turbine, known as Venturi wind turbine, has untraditional blades’ shape and special aerodynamic behavior that creates a venturi effect on the air stream passing through its aspherical shape. This article represents an integration of computational fluid dynamics and wind tunnel experimentation to study the aerodynamic performance of a manufactured model of energy ball wind turbine. Physical models with different twist angles were fabricated and tested in a small wind test section. In these experiments, dynamic torque, angular velocity, and coefficient of performance values were measured at different speeds. The experimental power coefficient results were discussed showing the best-tested twist angle. Fluid flow simulation has been developed in ANSYS FLUENT software. The findings of these numerical simulations have provided pressure contour, velocity contour, and torque values which help to study the solidity effect on turbine’s power coefficient. Nevertheless, the velocity contours provided from the computational analysis ensure the Venturi effect of the energy ball wind turbine design.

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