EFFECT OF SKIRT ANGLE AND FEATHERS FORMATION ON SHUTTLECOCK AERODYNAMICS PERFORMANCE

2015 ◽  
Vol 76 (8) ◽  
Author(s):  
Tajuddin Md. Jahi ◽  
Haziq Ikhwan Zawawi ◽  
Norazah Abd Rahman
Keyword(s):  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Spin Rotation ◽  
Design Parameters ◽  
World Federation ◽  
Cfd Analysis ◽  
Optimal Value ◽  
Computational Fluid Dynamics Cfd ◽  
Α Angle ◽  
Very High

Aerodynamic characteristics of badminton shuttlecock are significantly different from balls used in other sports. Shuttlecock can achieve a very high initial speed and at the same time, it can decelerate very fast. This is due to the significant aerodynamic drag it experiences during its in-flight motion. A computational fluid dynamics (CFD) analysis was carried out to understand the aerodynamics of a feathers shuttlecock approved by Badminton World Federation (BWF) for international tournaments. The aerodynamics performance of a standard shuttlecock at steady-state flight was investigated. The shuttlecock was assumed to be rigid and have no spin rotation; and velocity considered was 92 m/s. Effects of parameters such as angle of attack, α; angle of skirt, Ɵ; and angle of feathers, β; on the shuttlecock drag coefficient, Cd; were studied. It is found that smaller Ɵ leads to smaller Cd. Analysis shows that the Cd is the largest when the shuttlecock is at α = 0°. Besides that, the Cd is also influenced by β which the standard shuttlecock has fairly small Cd. Formation of feathers of the standard shuttlecock may be further twisted to the optimal value of β in order to increase its drag. As a result, Ɵ and β may be considered as design parameters in order to obtain the desired aerodynamics performance.

scholarly journals Pipeline Compressor Redesign With the Consideration of Both Noise and Performance

2000 ◽  
Author(s):  
Yuri I. Biba ◽  
Zheji Liu ◽  
D. Lee Hill
Keyword(s):  
High Efficiency ◽  
Aerodynamic Characteristics ◽  
The Body ◽  
Design Parameters ◽  
Original Design ◽  
Tonal Noise ◽  
Experimental Performance ◽  
Expected Performance ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance

A complete effort to redesign the aerodynamic characteristics of a single-stage pipeline compressor is presented. The components addressed are the impeller, diffuser region, and the volute. The innovation of this effort stems from the simultaneous inclusion of both the noise and aerodynamic performance as primary design parameters. The final detailed flange-to-flange analysis of the new components clearly shows that the operating range is extended and the tonal noise driven by the impeller is reduced. This is accomplished without sacrificing the existing high efficiency of the baseline machine. The body of the design effort uses both Computational Fluid Dynamics (CFD) and vibro-acoustics technology. The predictions are anchored by using the flange-to-flange analysis of the original design and its experimental performance data. By calculating delta corrections and assuming that these deltas are approximately the same for the new design, the expected performance is extrapolated.

Effect of moving surface on the aerodynamic drag of road vehicles

2005 ◽  
Vol 219 (2) ◽  
pp. 127-134 ◽  
Author(s):  
S N Singh ◽  
L Rai ◽  
P Puri ◽  
A Bhatnagar
Keyword(s):  
Fluid Dynamics ◽  
Boundary Layer ◽  
Rotational Speed ◽  
Aerodynamic Drag ◽  
Boundary Layer Separation ◽  
Rotating Cylinder ◽  
Cfd Analysis ◽  
Road Vehicles ◽  
Initial Value ◽  
Computational Fluid Dynamics Cfd

The effect on aerodynamic drag using a model of a truck has been investigated by controlling the boundary layer separation by the momentum injection method using a rotating cylinder. It involves the use of experiments coupled with computational fluid dynamics (CFD) analysis to validate the theory of momentum injection. Modelling of the truck has been done on the software GAMBIT©. The best suitable turbulence model was selected by comparing the results with the experimental results. The rotational speed and radius of the cylinder are varied to establish the effect of momentum injection on aerodynamic drag. The coefficient of drag reduces by approximately 35 per cent from an initial value of 0.51-0.32 for a cylinder of radius 1 cm with rotational speed of 4000 r/min.

scholarly journals Sabot Discard Characteristics under Different Spin Rates of the Rifled Barrel Launching APFSDS

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Chengqing Zhang ◽  
Huiyuan Wang ◽  
Ting Liu ◽  
Yingxian Duo
Keyword(s):  
Surface Pressure ◽  
Aerodynamic Characteristics ◽  
Intensity Change ◽  
Monitoring Point ◽  
Choked Flow ◽  
Optimal Value ◽  
Perfect Symmetry ◽  
Computational Fluid Dynamics Cfd ◽  
Aerodynamic Parameters ◽  
Quantization Parameters

The sabot discard asymmetry caused by spinning affects the exterior ballistic characteristics and shooting accuracy of a gun with the rifled barrel. To gain a deeper understanding of the complex sabot discard performance for the armor-piercing, fin-stabilized discarding sabot (APFSDS), a numerical investigation is performed to assess the effects of the spin rate on the sabot discard characteristics. We obtain the calculation boundary by the interior ballistics and the firing conditions and carry out a numerical simulation under different spin rates using computational fluid dynamics (CFD) and a dynamic mesh technique. We analyze four aspects of sabot discard characteristics, namely, sabot separation, rod surface pressure, rod aerodynamic parameters, and discarding quantization parameters. Computational results show that the sabot separation nearly presents perfect symmetry at 0 rad/s, and when the initial rate of the sabot increases, there is more obvious separation asymmetry, and it contributes to the relative position variation among the sabots and the rod. The distinction of rod surface pressure indicates that the choked flow is the strongest flow source, and the spin rate has almost no effect on the pressure of the rod front part. When the monitoring point moves towards the fins, the pressure distribution and intensity change more dramatically. The initial spin rate and separation asymmetry produce a variation in the surface pressure, which further influences the rod aerodynamic characteristics. The discarding quantization parameters exhibit a certain variation rule with its spin rate. 2,000 rad/s has a significant influence on the rod aerodynamic coefficients during the weak coupling phase. When the spin rate is in the range of 0–900 rad/s, the discarding characteristics remain the same. However, when the spin rate exceeds 900 rad/s, the separation time and aerodynamic impulse have a quadratic polynomial relationship with the rate. Additionally, a spin rate of 1,000 rad/s is the optimal value for a rifled barrel gun.

Investigation of effects of tire contour on aerodynamic characteristics and its optimization

2021 ◽  
pp. 095440702110586
Author(s):  
Lingxin Zhang ◽  
Haichao Zhou ◽  
Guolin Wang ◽  
Huiyun Li ◽  
Qingyang Wang
Keyword(s):  
Aerodynamic Drag ◽  
Great Influence ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Design Parameters ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Design Variables ◽  
Aerodynamic Drag Coefficient ◽  
Contour Design

Reducing the aerodynamic drag is one of the most important approaches for the development of energy-saving and environment-friendly automobiles. The tire contour has a great influence on the aerodynamic characteristics of automobiles. The aim of this study is to investigate the influence of the tire contour design parameters on the aerodynamic characteristics around a closed wheel, and obtain the optimized tire contour to reduce the automobile aerodynamic drag. A passenger car tire 185/65R14 was selected to conduct the wind tunnel test, and the surface pressure coefficients were used to validate the simulation model established using the detached eddy simulation (DES) model. To decrease tire drag, and taking the upper sidewall height, the tread radii, the tread width, and the transition arc radius of the shoulder as four design variables of contour, a combination of the Latin hypercube experimental design, the Kriging surrogate model, and the adaptive simulated annealing (ASA) algorithm were used to optimize the tire contour design parameters. The changes of flow field around the tire, including the velocity, turbulent kinetic energy, and pressure field were compared and analyzed for further understanding of the drag reduction mechanism. It is found that the aerodynamic drag coefficient of the optimized tire is reduced by 14.5%, and the aerodynamic coefficient drag of the car using the optimized tire is reduced by 7%. The present results are expected to provide useful information for designing new tire structures and improving the aerodynamic performance of the automobile.

SIMULATION OF A ROTATING DEVICE THAT REDUCES THE AERODYNAMIC DRAG OF AN AUTOMOBILE

2011 ◽  
Vol 35 (2) ◽  
pp. 229-249 ◽  
Author(s):  
Louis Gagnon ◽  
Marc J. Richard ◽  
Benoît Lévesque
Keyword(s):  
Aerodynamic Drag ◽  
Cfd Analysis ◽  
Optimal Conditions ◽  
Paddle Wheel ◽  
Flow Energy ◽  
Grid Interface ◽  
Angular Velocities ◽  
Sst Turbulence Model ◽  
Computational Fluid Dynamics Cfd ◽  
Dual Core

A two-dimensional Computational Fluid Dynamics (CFD) analysis of the Ahmed body is performed using the k-omega-SST turbulence model implemented in the OpenFOAM (OF) software. The analysis is then modified to include a rotating paddle wheel which captures energy from the swirl that forms behind the vehicle. The rotating wheel is implemented using a General Grid Interface (GGI) in the mesh. Flow energy is captured by the wheel and the power generated by the wheel reaches 16.1 W at optimal conditions. Overall drag reductions of up to 7.6% are also found as side-effects of the rotating paddle wheel. Computations are run in parallel on a dual core computer. A mesh of 30,000 cells is used. Y+ values on the walls of the vehicle range from 60 to 500. Tests are run at both fixed and variable paddle wheel angular velocities.

Multi-Objective Optimization of a Steam Surface Condenser Using the Territorial Particle Swarm Technique

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Pooya Mirzabeygi ◽  
Chao Zhang
Keyword(s):  
Particle Swarm ◽  
Design Parameters ◽  
Cfd Analysis ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Flow And Heat Transfer ◽  
Surface Condenser ◽  
Computational Fluid Dynamics Cfd ◽  
Shell And Tube ◽  
Outside Diameter

The multi-objective territorial particle swarm optimization (MOTPSO) technique is proposed in this work for the optimal design of steam surface condensers. The main objective of this work is to maximize the condensation rate in a condenser while the pressure loss is minimized. Various design parameters, such as the tube outside diameter, thickness, and pitch, are considered to find the optimal ones for shell and tube heat exchangers considered in this study. The two-dimensional computational fluid dynamics (CFD) analysis is performed to solve the fluid flow and heat transfer in the condenser to assess the performance of different designs.

scholarly journals CFD Investigations of the Effect of Rotating Wheels, Ride Height and Wheelhouse Geometry on the Drag Coefficient of Electric Vehicle

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Electric Vehicles ◽  
Aerodynamic Drag ◽  
Design Parameters ◽  
Ride Height ◽  
Full Vehicle ◽  
Maximum Range ◽  
Computational Fluid Dynamics Cfd

The development of electric vehicles demands minimizing aerodynamic drag in order to provide maximum range. The wheels contribute significantly to overall drag coefficient value because of flow separation from rims and wheel arches. In this paper various design parameters are investigated and their influence on vehicle drag coefficient is presented. The investigation has been done with the help of computational fluid dynamics (CFD) tools and with implementation of full vehicle setup with rotating wheels. The obtained results demonstrate changes in drag coefficient with respect to the change of design parameters.

scholarly journals Effect of Clearance and Cavity Geometries on Leakage Performance of a Stepped Labyrinth Seal

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1496
Author(s):  
Min Seok Hur ◽  
Soo In Lee ◽  
Seong Won Moon ◽  
Tong Seop Kim ◽  
Jae Su Kwak ◽  
...  
Keyword(s):  
Dimensionless Parameter ◽  
Flow Analysis ◽  
Labyrinth Seal ◽  
Performance Parameter ◽  
Design Parameters ◽  
Cfd Analysis ◽  
Cavity Size ◽  
Wide Range ◽  
Computational Fluid Dynamics Cfd ◽  
Leakage Characteristics

This study evaluated the leakage characteristics of a stepped labyrinth seal. Experiments and computational fluid dynamics (CFD) analysis were conducted for a wide range of pressure ratios and clearance sizes, and the effect of the clearance on the leakage characteristics was analyzed by determining the performance of the seal using a dimensionless parameter. It was observed from the analysis that the performance parameter of the seal decreases as the clearance size increases, but it tends to increase when the clearance size exceeds a certain value. In other words, it was revealed that there exists a specific clearance size (Smin) which minimizes the performance parameter of the seal. To identify the cause of this tendency change, a flow analysis was conducted using CFD. It was confirmed that the leakage characteristics of the stepped seal are affected by the size of the cavity, which is the space between the teeth. Therefore, a parametric study was conducted on the design parameters related to the cavity size (tooth height and pitch). The results show that the performance parameter decreases as the tooth height and pitch decreases. Moreover, Smin increases as the tooth height increases and the pitch decreases.

scholarly journals Aerodynamic Analysis of Rear Diffusers for a Passenger Car Using CFD

2020 ◽  
Author(s):  
Bugra Alkan
Keyword(s):  
Drag Reduction ◽  
Driving Forces ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Cfd Simulations ◽  
Fuel Prices ◽  
Computational Fluid Dynamics Cfd ◽  
Reduction Effect ◽  
Cost Efficient ◽  
Conventional Device

Increasing environmental pollution and fuel prices are the driving forces for automotive manufacturers to develop energy efficient vehicles with lower emissions. Improving the aerodynamic characteristics and reducing the aerodynamic drag resistance of a car is the easiest and cost efficient way to handle this problem. A conventional device to improve the aerodynamics that is used on sports and racing cars is a diffuser which improve the pressure recovery on the underbody. In this study, the drag reduction effect of a diffuser has been studied on a sedan car. To understand the effects of the diffuser, computational fluid dynamics (CFD) simulations has been performed. In these simulations, diffusers with different angles were simulated to find most effective drag reduction configuration. Analyses have shown that, it is possible to improve the aerodynamic characteristics by implementing diffusers at the vehicle’s underbody.

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