Effect of Body Cross Section on Projectile Aerodynamic Performance With Application to Electromagnetic (EM) Guns

2001 ◽  
Author(s):  
Paul Weinacht
Keyword(s):  
Cross Section ◽  
Aerodynamic Performance ◽  
Body Cross Section

scholarly journals CFD Investigation of Fluid Flow Over Aerofoil With and Without Dimple

2020 ◽  
Author(s):  
Uzair Sajjad ◽  
Khalid Hamid ◽  
Naseem Abbas
Keyword(s):  
Boundary Layer ◽  
Fluid Flow ◽  
Cross Section ◽  
Turbulence Model ◽  
Aerodynamic Performance ◽  
3D Analysis ◽  
Cad Model ◽  
Uniform Cross Section ◽  
Solid Works ◽  
Lift And Drag

Abstract This work labels the effect of dimples on aerodynamic performance of an airfoil. NACA 0018 having a uniform cross section has been evaluated in this study. Eclipse dimpled airfoil is tested and compared with plain airfoil and with the airfoil in the literature [23,24]. Flows taken into consideration are subsonic. The CAD model is drawn in Solid works 2016, while the simulations are performed in Ansys 18.3. A 2-D CFD investigation is performed on both models using k-w turbulence model, subsequently the better one is selected based on the results. 3D analysis is performed on a segment of airfoil having one dimple. Lift and drag coefficients are calculated for various angles of attack. This investigation tells that dimples affect the aerodynamics of airfoil, particularly for various angle of attacks. For smaller angle of attacks, plain airfoil showed less drag and higher lift, but totally different trend is achieved with increasing angle of attack whereas 20° was found to be the optimum angle. The findings proved that dimples on the surface delay the separation of boundary layer by generating additional turbulence on the surface and consequently reduce the formation of wake, which in turn decreases drag significantly.

Aeroelastic vibration analysis of wind turbine blade with Gurney flap

2020 ◽  
pp. 095440622097788
Author(s):  
Lin Chang ◽  
Yingjie Yu ◽  
Tingrui Liu
Keyword(s):  
Cross Section ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Parametric Design ◽  
Trust Region ◽  
Aerodynamic Performance ◽  
Least Square ◽  
Equivalent Model ◽  
Beam Model ◽  
Gurney Flap

In this paper, based on the parametric design of 3 D blades including typical cross-section and natural frequency calculation of the equivalent model, an integral method for aerodynamic performance and aeroelastic vibration analysis of blade with Gurney flap is proposed. Parametric design and unstructured grid are used to pre-process the blades with/without the Gurney flap. The discrete aerodynamic performance parameters distribution including the lift, drag, and torsion coefficients calculated by Fluent is fitted by the nonlinear least square method based on the trust-region algorithm, and the natural frequencies of the rotating blade are accurately solved by the equivalent thin-walled beam model and Green’s functions. Based on the aerodynamic performance coefficients and natural frequencies obtained by the accurate calculation above, the aeroelastic response equation of typical cross-section considering local aerodynamic damping matrix is established, and the vibration response of blade in flap and torsion direction is further described. From the analysis results, it can be seen that the Gurney flap structure can not only bring higher lift performance to the blade, but also can reduce the amplitude and vibration range of aeroelastic vibration, improve the aeroelastic stability of the blade, and prove the effectiveness of Gurney flap.

The Basic Performance Analysis of the Rail Vehicle Body

2013 ◽  
Vol 437 ◽  
pp. 42-46
Author(s):  
Jian Min Ju
Keyword(s):  
Cross Section ◽  
Computer Calculation ◽  
The Body ◽  
Vehicle Body ◽  
Body Structure ◽  
Load Carrying ◽  
Vehicle Structure ◽  
Overall Performance ◽  
Body Cross Section ◽  
Design And Manufacture

The design and manufacture of the vehicle structure determines of the safety and suitability during operation. For most designers, the bearing capacity of the vehicle body is not completely understood. The initial estimate of the vehicle is simply a uniform simply supported overhang beam structure. With the development of computer technology, people can use more complex and closer to the actual body computational model, but it generally requires a lot of work, and designers are often only able to see the final result. It is not clear that the factors affect Load-carrying properties of the body structure. Designers often can not look find a process of improving the design. This method to scan the body structure by a computer calculation and analysis, the geometry, mechanical properties of parameters of the body cross-section has been plotted map. You can quickly and accurately understand the overall performance of the body, analysis the performance difference of different body cross-section. Reasonableness and balance of the body can be measured and awarded. In general, it is very important for the designer of the vehicle.

scholarly journals Evaluation and minimization of moment coefficient of tall buildings with trilateral cross-section via a surrogate model

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
M. Noormohamadian ◽  
E. Salajegheh
Keyword(s):  
Cross Section ◽  
Surrogate Model ◽  
Polynomial Regression ◽  
Computational Cost ◽  
Tall Buildings ◽  
Aerodynamic Performance ◽  
Tall Building ◽  
Geometrical Parameters ◽  
Moment Coefficient ◽  
The Moment

AbstractWind load is commonly regarded as the dominant lateral load in designing tall buildings. Thus, it is of necessity to investigate the parameters affecting wind-induced loads. One of these parameters is the exterior shape of tall building, which using its aerodynamic shape modifications, wind loads, can be decreased. In this research, the exterior shape of different tall buildings with trilateral cross-section is constructed via the polynomial parameterization method. The advantage of the proposed method in producing the building geometry is that it is able to apply all aerodynamic modifications to triangular buildings. Then, the effect of each geometrical parameter on the moment coefficient along the drag is investigated as the aerodynamic response of tall buildings. Using geometric parameters screening, it was found that two geometrical parameters (T, b1) have the maximum impact on the aerodynamic response of the tall buildings which apply twist and curved sides modifications, respectively. Then, using the polynomial regression method, explicit relation of the mean moment coefficient in terms of these two geometrical parameters is illustrated using a third-order polynomial, which can be used as a surrogate model to evaluate the moment coefficient instead of computational fluid dynamic analysis. The surrogate model can significantly reduce the computational cost, and operate as an appropriate guide for building designers to investigate the effect of building geometrical variables on aerodynamic performance. Finally, the minimum point of the proposed model is determined as the optimal shape of the tall building. In addition, a comparative analysis of the aerodynamic responses of the optimal model with the basic triangle model shows that the moment coefficient is reduced by 56%. This demonstrates the considerable effect of these two geometrical parameters in improving the aerodynamic performance.

Design of S-Shaped Submerged Inlet

2011 ◽  
Vol 291-294 ◽  
pp. 349-354
Author(s):  
Guang Lin He ◽  
Xiao Lin Li
Keyword(s):  
Cross Section ◽  
Total Pressure ◽  
Aerodynamic Performance ◽  
New Method ◽  
Pressure Recovery ◽  
Recovery Coefficient ◽  
Distortion Coefficient ◽  
Total Pressure Recovery ◽  
The Cross ◽  
Pressure Recovery Coefficient

The influence of centerline and the cross-section variation to aerodynamic performance of the inlet was researched in a wider range. A new method of measuring the total pressure recovery coefficient and total pressure distortion coefficient of the inlet was proposed. Based on the loitering aircraft, a s-shaped inlet was designed to meet the needs of stable flight of loitering aircraft, whose total pressure recovery coefficient is 93.2% and total pressure distortion coefficient is 1.2%.

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

2020 ◽  
Author(s):  
Aniruddha Deepak Paranjape ◽  
Anhad Singh Bajaj ◽  
Shaheen Thimmaiah Palanganda ◽  
Radha Parikh ◽  
Raahil Nayak ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Cross Section ◽  
Computational Analysis ◽  
Aerodynamic Performance ◽  
Rotor Blades ◽  
Navier Stokes ◽  
Cfd Analysis ◽  
High Lift ◽  
Actuator Disk ◽  
Computational Fluid Dynamics Cfd

Abstract. The present study aims to analyze the basic aerodynamic performance of a Diffuser Augmented Wind Turbine (DAWT) using high lift generating airfoils in the diffuser cross-section that encloses the turbine. The study is a Computational Fluid Dynamics (CFD) analysis of the flow across the rotor blades and through the diffuser, which is carried out using Reynolds Averaged Navier-Stokes (RANS) simulations. The rotor blades are modeled as a porous Actuator Disk (AD). Various high-lift generating airfoils are used in the diffuser geometries with additional geometric modifications, such as a flange, are taken into consideration and analyzed for the velocity of the flow at the actuator disk to determine the overall aerodynamic performance of the diffuser shape.

Experimental and Numerical Study on Flapping Wing Kinematics and Aerodynamics of Coleoptera

2006 ◽  
Vol 326-328 ◽  
pp. 175-178 ◽  
Author(s):  
Saputra ◽  
Do Young Byun ◽  
Yung Hwan Byun ◽  
Hoon Cheol Park
Keyword(s):  
Cross Section ◽  
High Speed ◽  
Numerical Study ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Wing Kinematics ◽  
Wing Motion ◽  
Edge Vortex ◽  
Flapping Mechanism ◽  
Aerodynamic Simulation

In this study we have experimentally and numerically analyzed the flapping mechanism and wing kinematics of coleoptera (Propylea japonica Thunberg). Using digital high speed camera, we captured the continuous wing kinematics and visualized the flight motion of the free-flying coleoptera. The experimental visualization shows that the elytra flapped concurrently with the main wing both in the downstroke and upstroke motions. In order to define the wing kinematics of coleoptera, the displacement of a wing cross section (50% span-wise) was measured for each sequence of the wing motion. Using these data, the flight motion of coleoptera was numerically simulated to investigate the aerodynamic performance. The computational aerodynamic simulation shows that leading edge vortex shedding plays a key role in generating lift to keep the insect aloft.

Secondary Flow Measurements in a Compressor Cascade Using 3D LDA/PDA: Part B — Dispersed Phase Effects on Flow Topology

2019 ◽  
Author(s):  
Janneck Harbeck ◽  
Silvio Geist ◽  
Franz Joos
Keyword(s):  
Gas Turbine ◽  
Cross Section ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Dispersed Phase ◽  
Inlet Temperature ◽  
Compressor Cascade ◽  
Flow Topology ◽  
Flow Measurements ◽  
The Impact

Abstract The rapid regulation of gas turbine power plants is becoming increasingly important. In the field of stationary gas turbine power augmentation droplet-laden flows receive special attention as they cool the compressor’s inlet temperature. High fogging is an effective and economic method that secures power supply by reacting rapidly to fluctuating power generation. However, water droplets effect the aerodynamic performance of the compressor negatively. Therefore, the Laboratory of Turbomachinery investigated the interaction between droplets and blades at midspan by using diverse experimental methods to comprehend aerodynamic performance and water film induced losses. Additionally, the knowledge of the separation’s extent for three-dimensional flows with corner separation is of great importance as it leads to a blockage of the flow cross-section and therefore contributes to the losses. This paper enlarges this knowledge base by studying the interactions of the dispersed phase with the gas flow in three-dimensional flow structures as they are found in the near wall regions of every turbo compressor. By utilizing a three-dimensional Phase-Doppler Anemometer spatially resolved information on velocity mean vector, its higher moments as well as droplet diameters were extracted from the separated region for a compressor blade, in middle cross section design, with spray-injection. Streamlines that derive from the mean velocities visualize key features such as saddle and focal points. Then an integral approach is presented to evaluate the effect of the dispersed phase on the flow structure compared to dry flow and the impact back on different diameter classes. Finally, the velocity in streamwise direction shows the influence of the disperse phase on the aerodynamic blockage.

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