scholarly journals A comparative pressure analysis of air flow between horizontal and V-Tail of UAV MALE of NACA0012H with speed variation

2018 ◽  
Vol 154 ◽  
pp. 01115
Author(s):  
Rahmat Riza ◽  
Dicky Kurniawan ◽  
Arif Budi Wicaksono
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Unmanned Aerial Vehicle ◽  
Air Flow ◽  
Leading Edge ◽  
Trailing Edge ◽  
Speed Variation ◽  
Aerial Vehicle ◽  
Long Endurance ◽  
Pressure Analysis

NACA0012H is an airfoil type that could be used for Unmanned Aerial Vehicle Medium Altitude Long Endurance. This experiment was used to analyze stress in the surface of Tail of UAV MALE that was caused by air flow. The experiment was conducted using Computational Fluid Dynamics Software. Two designs of tail, horizontal and V-tail, were considered to simulate pressure occurred on the surface of leading edge, chamber and trailing edge. The simulation was developed varying the speed of the UAV MALE. The results showed that pressure occurred on the surface of horizontal tail higher than pressure on the V-tail.

scholarly journals Design and Validation of a New Morphing Camber System by Testing in the Price—Païdoussis Subsonic Wind Tunnel

Aerospace ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 23 ◽  
Author(s):  
David Communier ◽  
Ruxandra Mihaela Botez ◽  
Tony Wong
Keyword(s):  
Wind Tunnel ◽  
Unmanned Aerial Vehicle ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Trailing Edge ◽  
Subsonic Wind Tunnel ◽  
Aerial Vehicle ◽  
Stall Angle

This paper presents the design and wind tunnel testing of a morphing camber system and an estimation of performances on an unmanned aerial vehicle. The morphing camber system is a combination of two subsystems: the morphing trailing edge and the morphing leading edge. Results of the present study show that the aerodynamics effects of the two subsystems are combined, without interfering with each other on the wing. The morphing camber system acts only on the lift coefficient at a 0° angle of attack when morphing the trailing edge, and only on the stall angle when morphing the leading edge. The behavior of the aerodynamics performances from the MTE and the MLE should allow individual control of the morphing camber trailing and leading edges. The estimation of the performances of the morphing camber on an unmanned aerial vehicle indicates that the morphing of the camber allows a drag reduction. This result is due to the smaller angle of attack needed for an unmanned aerial vehicle equipped with the morphing camber system than an unmanned aerial vehicle equipped with classical aileron. In the case study, the morphing camber system was found to allow a reduction of the drag when the lift coefficient was higher than 0.48.

A computational fluid dynamics investigation of subsonic wing designs for unmanned aerial vehicle application

2019 ◽  
Vol 233 (15) ◽  
pp. 5543-5552
Author(s):  
Z Siddiqi ◽  
JW Lee
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Aspect Ratio ◽  
Unmanned Aerial Vehicle ◽  
Wing Design ◽  
Ansys Fluent ◽  
High Lift ◽  
Aerial Vehicle ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

The wing of an unmanned aerial vehicle, RQ-7 Shadow, is modified to study the changes in the aerodynamics of the wing. The main focus is to investigate the effects of changing the components of wing design when the aircraft climbs and accelerates. These component modifications included changing the airfoil, planform, aspect ratio, and adding a winglet. Another objective is to study the efficacy of employing high-lift airfoils like the EPPLER 559 for subsonic unmanned aerial vehicle applications. For this, five wing designs are considered in this paper. Computational fluid dynamics simulations using ANSYS FLUENT® are conducted for each wing design. The C L /C D ratios for all the wings are calculated at increasing angles of attack (simulating Climbing) and increasing speed (simulating Acceleration). Compared to the NACA 4415 airfoil, which is utilized by the RQ-7 Shadow, the EPPLER 559 provides an increase in lift at the low angles of attack, but yields less of these benefits as the angle of attack increases. The tapered planform significantly reduces the high drag associated with the EPPLER 559 airfoil. The generation of higher lift forces with lower drag is further achieved by increasing the aspect ratio and through the addition of a winglet. When compared to the NACA 4415 airfoil, it is concluded that the EPPLER 559 airfoil is a viable candidate for subsonic unmanned aerial vehicle applications only when the components of wing design are altered. The performance of the wings that employ the EPPLER 559 airfoil improves when the planform is changed from rectangular to tapered, when the aspect ratio is increased and when a winglet is added.

Sea-unammned aerial vehicle takeoff characteristics analysis method based on approximate equilibrium hypothesis

2018 ◽  
Vol 233 (3) ◽  
pp. 916-927 ◽  
Author(s):  
Dongli Ma ◽  
Zhi Li ◽  
Muqing Yang ◽  
Yang Guo ◽  
Haode Hu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Unmanned Aerial Vehicle ◽  
Interpolation Method ◽  
Design Stage ◽  
Approximate Equilibrium ◽  
Characteristics Analysis ◽  
Aerial Vehicle ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

In this paper, transient multiphase flow computational fluid dynamics simulations based on volume of fluid model are conducted for a sea-unmanned aerial vehicle. The approximate equilibrium hypothesis is implemented after estimating the acceleration in the vertical direction. The complete configuration model and hull model are employed in simulation to predict the aerodynamic and hydrodynamic forces separately for different demands of aerodynamic and hydrodynamic computational fluid dynamics predictions and computing efficiency. In takeoff characteristics analysis, the computational fluid dynamics simulations are conducted as inputs for piecewise interpolation method. The calculated results show that the sea-unmanned aerial vehicle takeoff characteristics are totally different from a conventional aircraft. The drag-peak at hump speed is the obvious feature of the sea-unmanned aerial vehicle/seaplane. In most cases, if a sea-unmanned aerial vehicle will takeoff successfully as long as it can pass the drag peak. The takeoff distance and time calculated by piecewise interpolation method match the experimental data within 7% deviation. The accuracy is acceptable for conceptual design stage of a sea-unmanned aerial vehicle/seaplane. The results are applicable to consultation in choosing takeoff field or choosing powerplant.

Study on the effect of leading and trailing-edge serrations on flat-plate broadband noise

2020 ◽  
Vol 51 (3) ◽  
pp. 44-51
Author(s):  
Dilip A Shah ◽  
Husain A Hamid ◽  
M Praveen Kumar ◽  
Tanmay Atul Bhise ◽  
GC Vishnu Kumar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flat Plate ◽  
Computational Study ◽  
Leading Edge ◽  
Broadband Noise ◽  
Flat Plates ◽  
Trailing Edge ◽  
Ansys Fluent ◽  
Trailing Edges

The results of a comparative study on the reduction of broadband noise for several combinations of a flat plate with serrations encountering a low-turbulence fluid flow are computed and documented. The four combinations under study are triangular serrations on leading-edge only, triangular serrations on trailing-edge only, triangular serrations on the leading and trailing edges, and ogival serrations on the leading and trailing edges. Serrations based on the trailing edge are normalized in terms of its chord length. A computational study was carried out using computational fluid dynamics models to simulate the variety of serrated flat plates. Commercial computational fluid dynamics software ANSYS Fluent 16.0 was used. A quantifiable reduction in the broadband noise was found in most of the variations in the serrated geometries. The particular case of the serrations considered in the present study having triangular serrations on both leading and trailing edges of the flat plate proved to be the most effective in terms of broadband noise reduction.

scholarly journals Coupling Computational Fluid Dynamics Simulations and Statistical Moments for Designing Healthy Indoor Spaces

2019 ◽  
Vol 16 (5) ◽  
pp. 800 ◽  
Author(s):  
Shamia Hoque ◽  
Firoza Omar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Air Flow ◽  
Particle Dispersion ◽  
Statistical Moments ◽  
Dispersion Pattern ◽  
Case Scenario ◽  
Worst Case ◽  
Site Specific ◽  
Indoor Spaces

Cross-contamination between occupants in an indoor space may occur due to transfer of infectious aerosols. Computational fluid dynamics (CFD) provides detailed insight into particle transport in indoor spaces. However, such simulations are site-specific. This study couples CFD with statistical moments and establishes a framework that transitions site-specific results to generating guidelines for designing “healthy” indoor spaces. Eighteen cases were simulated, and three parameters were assessed: inlet/outlet location, air changes per hour, and the presence/absence of desks. Aerosol release due to a simulated “sneeze” in a two-dimensional ventilated space was applied as a test case. Mean, standard deviation, and skewness of the velocity profiles and particle locations gave an overall picture of the spread and movement of the air flow in the domain. A parameter or configuration did not dominate the values, confirming the significance of considering the combined influence of multiple parameters for determining localized air-flow characteristics. Particle clustering occurred more when the inlet was positioned above the outlet. The particle dispersion pattern could be classified into two time zones: “near time”, <60 s, and “far time”, >120 s. Based on dosage, the 18 cases were classified into three groups ranging from worst case scenario to best case scenario.

Construction Ventilation Scheme Optimization of Underground Main Powerhouse Based on CFD

2013 ◽  
Vol 368-370 ◽  
pp. 619-623
Author(s):  
Zhen Liu ◽  
Xiao Ling Wang ◽  
Ai Li Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Air Flow ◽  
Scheme Optimization ◽  
Pressure Distributions ◽  
Air Volume ◽  
Computational Fluid Dynamics Cfd ◽  
Traditional Construction ◽  
Ventilation Scheme

For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground main powerhouse is simulated by the computational fluid dynamics (CFD) to optimize ventilation parameters. A 3D unsteady RNG k-ε model is performed for construction ventilation in the underground main powerhouse. The air-flow field and CO diffusion in the main powerhouse are simulated and analyzed. The two construction ventilation schemes are modelled for the main powerhouse. The optimized ventilation scheme is obtained by comparing the air volume and pressure distributions of the different ventilation schemes.

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