scholarly journals Airfoil Analysis and Effect of Wing Shape Optimization on Aerodynamic Parameters in a Steady Flight

2021 ◽  
pp. 43-53
Author(s):  
Vishu K. Oza ◽  
Hardik R. Vala
Keyword(s):  
Lattice Method ◽  
Vortex Lattice Method ◽  
Layer Analysis ◽  
Tail Structure ◽  
Aerial Vehicle ◽  
Wing Geometry ◽  
Aerodynamic Parameters ◽  
Improved Performance ◽  
The Impact ◽  
Drag Ratio

The work in this paper deals with reconstructing and optimizing the wing geometry of an Unmanned Combat Aerial Vehicle for improved performance and reviewing the impact of the modification on flight parameters in a steady flight. The behavior of airfoils at planned flight conditions under I.S.A. is checked in XFLR5 software. Following up by 2-D CFD and boundary layer analysis of former and new airfoil, dimensions of the wing are re-developed, keeping the fuselage and tail structure same. The existing wing and the optimized wing design is analyzed by Vortex Lattice Method and Triangular Panel Method, with an objective to make the shape of the wing aerodynamically suitable for an increased Lift to Drag ratio and thereby minimizing drag coefficients.

scholarly journals On Boeing 737 – 300 Wing Aerodynamics Calculations Based on VLM Theory

2018 ◽  
Vol 1 (1) ◽  
pp. 95
Author(s):  
Jacob Nagler
Keyword(s):  
Vortex Lattice ◽  
Center Of Pressure ◽  
Location Error ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Wing Geometry ◽  
Finite Wing ◽  
Using Data ◽  
Wing Aerodynamics

<p>In this paper, aerodynamics coefficients of Boeing 737-300 were calculated using VLM (vortex lattice method) theory. The wing was assumed to be planar and was divided into 6×6 panels, which were in the trapezoid shape. Aerodynamics lifting and moment coefficients were calculated. Also, center of pressure location was found using data from VLM and wing geometry. Comparisons between literature, finite wing theory and VLM theory were done. It was found that maximum lifting coefficient error between literature and VLM was about 4.0%. Moreover, that between finite wing theory and VLM was about 2.2%. Center of pressure location error between finite wing theory and VLM was about 0.5%.</p>

scholarly journals Aerodynamic Design of a Tailless Aeroplan

10.14311/268 ◽  
2001 ◽  
Vol 41 (4-5) ◽  
Author(s):  
J. Friedl
Keyword(s):  
Reynolds Numbers ◽  
Aerodynamic Characteristics ◽  
Strength Analysis ◽  
Aerodynamic Design ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Analysis And Design ◽  
Moment Coefficient ◽  
Wing Geometry ◽  
Design Requirements

The paper presents an aerodynamic analysis of a one-seat ultralight (UL) tailless aeroplane named L2k, with a very complicated layout. In the first part, an autostable airfoil with a low moment coefficient was chosen as a base for this problem. This airfoil was refined and modified to satisfy the design requirements. The computed aerodynamic characteristics of the airfoils for different Reynolds numbers (Re) were compared with available experimental data. XFOIL code was used to perform the computations. In the second part, a computation of wing characteristics was carried out. All calculated cases were chosen as points on the manoeuvring and gust envelope. The vortex lattice method was used with consideration of fuselage and winglets for very complicated wing geometry. The PMW computer program developed at IAE was used to perform the computations. The computed results were subsequently used for structural and strength analysis and design.

Generalized vortex lattice method for planar supersonic flow

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1230-1233
Author(s):  
Paulo A. O. Soviero ◽  
Hugo B. Resende
Keyword(s):  
Supersonic Flow ◽  
Vortex Lattice ◽  
Lattice Method ◽  
Vortex Lattice Method

Relay Selection-aware Non-orthogonal Multiple Access Networks: Direct and Relaying Mode

2020 ◽  
Vol 13 (3) ◽  
pp. 348-354
Author(s):  
Dinh-Thuan Do ◽  
Minh-Sang V. Nguyen
Keyword(s):  
Relay Selection ◽  
Multiple Access ◽  
Decode And Forward ◽  
Selection Scheme ◽  
Fixed Power ◽  
Transmission Quality ◽  
Improved Performance ◽  
Outage Probabilities ◽  
Future Work ◽  
The Impact

Objective: In this paper, Decode-and-Forward (DF) mode is deployed in the Relay Selection (RS) scheme to provide better performance in cooperative downlink Non-orthogonal Multiple Access (NOMA) networks. In particular, evaluation regarding the impact of the number of multiple relays on outage performance is presented. Methods: As main parameter affecting cooperative NOMA performance, we consider the scenario of the fixed power allocations and the varying number of relays. In addition, the expressions of outage probabilities are the main metric to examine separated NOMA users. By matching related results between simulation and analytical methods, the exactness of derived formula can be verified. Results: The intuitive main results show that in such cooperative NOMA networks, the higher the number of relays equipped, the better the system performance can be achieved. Conclusion: DF mode is confirmed as a reasonable selection scheme to improve the transmission quality in NOMA. In future work, we will introduce new relay selections to achieve improved performance.

scholarly journals Static Aeroelastic Characteristics of Morphing Trailing-Edge Wing Using Geometrically Exact Vortex Lattice Method

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Sen Mao ◽  
Changchuan Xie ◽  
Lan Yang ◽  
Chao Yang
Keyword(s):  
Vortex Lattice ◽  
Deflection Angle ◽  
Aircraft Design ◽  
Analysis Method ◽  
Lattice Method ◽  
Trailing Edge ◽  
Vortex Lattice Method ◽  
Analysis And Design ◽  
Aeroelastic Analysis ◽  
Typical Model

A morphing trailing-edge (TE) wing is an important morphing mode in aircraft design. In order to explore the static aeroelastic characteristics of a morphing TE wing, an efficient and feasible method for static aeroelastic analysis has been developed in this paper. A geometrically exact vortex lattice method (VLM) is applied to calculate the aerodynamic forces. Firstly, a typical model of a morphing TE wing is chosen and built which has an active morphing trailing edge driven by a piezoelectric patch. Then, the paper carries out the static aeroelastic analysis of the morphing TE wing and corresponding simulations were carried out. Finally, the analysis results are compared with those of a traditional wing with a rigid trailing edge using the traditional linearized VLM. The results indicate that the geometrically exact VLM can better describe the aerodynamic nonlinearity of a morphing TE wing in consideration of geometrical deformation in aeroelastic analysis. Moreover, out of consideration of the angle of attack, the deflection angle of the trailing edge, among others, the wing system does not show divergence but bifurcation. Consequently, the aeroelastic analysis method proposed in this paper is more applicable to the analysis and design of a morphing TE wing.

scholarly journals The Influence of Video Format on Engagement and Performance in Online Learning

2021 ◽  
Vol 11 (2) ◽  
pp. 128
Author(s):  
Sergej Lackmann ◽  
Pierre-Majorique Léger ◽  
Patrick Charland ◽  
Caroline Aubé ◽  
Jean Talbot
Keyword(s):  
Student Performance ◽  
Cognitive Engagement ◽  
Emotional Engagement ◽  
Emotional States ◽  
Lecture Capture ◽  
Improved Performance ◽  
And Performance ◽  
Subject Experiment ◽  
The Impact ◽  
Video Format

Millions of students follow online classes which are delivered in video format. Several studies examine the impact of these video formats on engagement and learning using explicit measures and outline the need to also investigate the implicit cognitive and emotional states of online learners. Our study compared two video formats in terms of engagement (over time) and learning in a between-subject experiment. Engagement was operationalized using explicit and implicit neurophysiological measures. Twenty-six (26) subjects participated in the study and were randomly assigned to one of two conditions based on the video shown: infographic video or lecture capture. The infographic video showed animated graphics, images, and text. The lecture capture showed a professor, providing a lecture, filmed in a classroom setting. Results suggest that lecture capture triggers greater emotional engagement over a shorter period, whereas the infographic video maintains higher emotional and cognitive engagement over longer periods of time. Regarding student learning, the infographic video contributes to significantly improved performance in matters of difficult questions. Additionally, our results suggest a significant relationship between engagement and student performance. In general, the higher the engagement, the better the student performance, although, in the case of cognitive engagement, the link is quadratic (inverted U shaped).

Energy absorbed ability and damage analysis for honeycomb sandwich material of bio-inspired micro aerial vehicle under low velocity impact

2020 ◽  
pp. 095440622097542
Author(s):  
Jianxun Du ◽  
Peng Hao ◽  
Mabao Liu ◽  
Rui Xue ◽  
Lin’an Li
Keyword(s):  
Honeycomb Structure ◽  
Low Velocity Impact ◽  
Parameter Study ◽  
Low Velocity ◽  
Micro Aerial Vehicle ◽  
Thin Walled Structures ◽  
Wide Range ◽  
Aerial Vehicle ◽  
Thin Walled ◽  
The Impact

Because of the advantages of light weight, small size, and good maneuverability, the bio-inspired micro aerial vehicle has a wide range of application prospects and development potential in military and civil areas, and has become one of the research hotspots in the future aviation field. The beetle’s elytra possess high strength and provide the protection of the abdomen while being functional to guarantee its flight performance. In this study, the internal microstructure of beetle’s elytra was observed by scanning electron microscope (SEM), and a variety of bionic thin-walled structures were proposed and modelled. The energy absorption characteristics and protective performance of different configurations of thin-walled structures with hollow columns under impact loading was analyzed by finite element method. The parameter study was carried out to show the influence of the velocity of impactor, the impact angle of the impactor and the wall thickness of honeycomb structure. This study provides an important inspiration for the design of the protective structure of the micro aerial vehicle.

A Novel Design of Landing Gear Oleo Strut Damper Using MR Fluid for Aircraft and UAV’s

2012 ◽  
Vol 225 ◽  
pp. 275-280
Author(s):  
Chandra B. Asthana ◽  
Rama B. Bhat
Keyword(s):  
Shock Absorber ◽  
Fluid Viscosity ◽  
Simulation Approach ◽  
Body Frame ◽  
Mr Fluid ◽  
Orifice Area ◽  
Aerial Vehicle ◽  
Impact Kinetic Energy ◽  
The Impact ◽  
Novel Design

Most landing gears used in aircraft employ very efficient oleo-pneumatic dampers to absorb and dissipate the impact kinetic energy of the aircraft body frame. A single-acting shock absorber is most commonly used in the oleo strut that has a metering pin extending through the orifice, which can vary the orifice area upon compression and extension of the strut. This variation is adjusted by shaping the metering pin so that the strut load is fairly constant under dynamic loading. In this paper, it is proposed to further change the damping coefficient as a function of time in order to achieve a semi-active control of the aircraft vibrations during landing by using Magnetorheological (MR) fluid in the Oleo. With the metering pin designed for a nominal flight condition, further variation in the fluid viscosity would help achieve the optimal performance in off-nominal flight conditions. A simulation approach is employed to show the effect of different profiles for viscosity variation in the MR fluid. The utility of such a damper can be very well exploited to include different criteria such as the landing distance after touchdown. This type of system can be used also in Unmanned Aerial Vehicle (UAV) application where the focus of design may be to accomplish the task without the consideration of passenger comfort.

scholarly journals Firm Level Strategy, Organization Culture and Performance of Food and Beverage Manufacturing Firms in Kenya

2018 ◽  
Vol 13 (8) ◽  
pp. 224 ◽  
Author(s):  
Zachary B. Awino ◽  
Dominic C. Muteshi ◽  
Reginah K. Kitiabi ◽  
Ganesh P. Pokhariyal
Keyword(s):  
Policy Formulation ◽  
Manufacturing Firms ◽  
Organization Culture ◽  
Hierarchical Regression ◽  
Firm Level ◽  
Food And Beverage ◽  
Improved Performance ◽  
And Performance ◽  
The Impact ◽  
The Relationship

The study tested the impact of organization culture on the on the relationship between firm-level strategy and performance of food and beverage manufacturing firms in Kenya. The opinion of the CEO/MDs from 125 firms in this sector was sought by application of a structured questionnaire; the collected data was analysed using hierarchical regression analysis. The paper stated hypothesis that organizational culture has a significant effect on the relationship between firm-level strategy and performance. The results supported the hypothesis. Therefore, firm development of strong organization culture to support firm-level strategy for higher performance is paramount. These findings will contribute to government policy formulation for sector’s expansion and competitiveness and management drives in building a positive organization culture to support firm-level strategy for improved performance.

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