FLIGHT PERFORMANCE OF VARIOUS BLENDED WING-BODY SMALL UAV DESIGNS

2015 ◽  
Vol 75 (8) ◽  
Author(s):  
Rizal E. M. Nasir ◽  
Firdaus Mohamed ◽  
Ramzyzan Ramly ◽  
Aman M. I. Mamat ◽  
Wirachman Wisnoe ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Optimal Number ◽  
Total Weight ◽  
Maximum Speed ◽  
Flight Performance ◽  
Endurance Range ◽  
Small Uav ◽  
Flight Envelope ◽  
Blended Wing Body ◽  
Near Future

Currently there are four BWB designs that have been tested in the LST-1 wind tunnel at Flight Technology and Test Centre (FTTC), UiTM since 2005. The objective of this paper is to analyse their flight performance of these four BWB UAVs in terms of airspeed flight envelope, endurance, range and rate of climb as a function of the number of batteries and to determine the optimal number of batteries to be carried for 1-hour endurance mission and 3-hour endurance mission. The targeted cruising-loitering airspeed mission for all these BWBS are around 20 to 40 mph (8.9 m/s to 17.8 m/s) and they are to possess the lowest take off/landing speed and the highest maximum speed possible. This paper also seeks to find the best design of the four to explore its maximum potential in the near future where a prototype will be constructed. Unlike conventionally powered aircraft that uses fuel, which burns out thus reducing total weight of aircraft as it flies for long hours, these four BWB electric-powered vehicles carry batteries and the weight shall remain constant throughout the flight. 

A Roundabout for Studying Sustained Flight of Locusts

1952 ◽  
Vol 29 (2) ◽  
pp. 211-219 ◽  
Author(s):  
AUGUST KROGH ◽  
TORKEL WEIS-FOGH
Keyword(s):  
Wind Tunnel ◽  
External Factors ◽  
Flight Performance ◽  
Average Speed ◽  
Preliminary Results ◽  
Air Resistance

A roundabout technique is described which makes it possible to study the flight performance of a small ‘swarm’ of locusts (up to thirty-two individuals) for hours at a time. The resistance of the roundabout was compensated by means of a mill so that the locusts only had to overcome their own air resistance. The speed of the revolving periphery therefore equalled the preferred average flying speed of the suspended locusts. The average speed during a period, as well as the variation in speed in the course of an experiment, were found to be the same in the roundabout and in experiments where single locusts flew in front of a wind tunnel. In the latter case the insects flew in completely normal flight posture. It was concluded that the results obtained with the roundabout were as valid as the results obtained with a wind tunnel. Some preliminary results are given on the influence of different external factors on the flying speed and the ability to endure sustained flight.

scholarly journals Geometric Effects Analysis and Verification of V-Shaped Support Interference on Blended Wing Body Aircraft

2020 ◽  
Vol 10 (5) ◽  
pp. 1596
Author(s):  
Xin Xu ◽  
Qiang Li ◽  
Dawei Liu ◽  
Keming Cheng ◽  
Dehua Chen
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Pitching Moment ◽  
Straight Section ◽  
Test Results ◽  
Wind Tunnel Tests ◽  
Blended Wing Body ◽  
Support Interference ◽  
Geometric Effects ◽  
Good Agreement

A special V-shaped support for blended wing body aircraft was designed and applied in high-speed wind tunnel tests. In order to reduce the support interference and explore the design criteria of the V-shaped support, interference characteristics and geometric parameter effects of V-shaped support on blended wing body aircraft were numerically studied. According to the numerical results, the corresponding dummy V-shaped supports were designed and manufactured, and verification tests was conducted in a 2.4 m × 2.4 m transonic wind tunnel. The test results were in good agreement with the numerical simulation. Results indicated that pitching moment of blended wing body aircraft is quite sensitive to the V-shaped support geometric parameters, and the influence of the inflection angle is the most serious. To minimize the pitching moment interference, the straight-section diameter and inflection angle should be increased while the straight-section length should be shortened. The results could be used to design special V-shaped support for blended wing body aircraft in wind tunnel tests, reduce support interference, and improve the accuracy of test results.

On the Evaluation of Negative Altitude Requirement for Flutter Speed Boundary of Transport Aircraft and UAV

2012 ◽  
Vol 225 ◽  
pp. 397-402 ◽  
Author(s):  
Erwin Sulaeman
Keyword(s):  
Mach Number ◽  
Atmospheric Condition ◽  
Aircraft Design ◽  
Maximum Speed ◽  
Flight Safety ◽  
Transport Aircraft ◽  
Aeroelastic Instability ◽  
Flight Envelope ◽  
Constant Altitude ◽  
Standard Regulation

To maintain flight safety, all transport aircraft designs should satisfy airworthiness standard regulation. One fundamental issue of the aircraft design that relates directly to flight safety as well as commercial aspect of the aircraft is on the evaluation of the maximum speed within the designated flight envelope. In the present work, a study is performed to evaluate the negative altitude requirement related to aeroelastic instability analysis as one requirement that should be fulfilled to design the maximum speed. An analytical derivation to obtain the negative altitude is performed based on the airworthiness requirement that a transport airplane must be designed to be free from aeroelastic instability within the flight envelope encompassed by the dive speed or dive Mach number versus altitude envelope enlarged at all points by an increase of 15% in equivalent airspeed at both constant Mach number and constant altitude. To take into account variation in atmospheric condition as function of altitude, the international standard regulation is used as referenced. The analysis result shows that a single negative altitude can be obtained using these criteria regardless of the dive speed or dive Mach number. A further discussion on the application of the negative altitude concept to UAV (Unmanned Aerial Vehicle), in relation to UAV Standard Airworthiness Requirement STANAG 4671, is presented.

The Effect of Canard to the Aerodynamic Behavior of Blended Wing Body Aircraft

2012 ◽  
Vol 225 ◽  
pp. 38-42
Author(s):  
Zurriati Mohd Ali ◽  
Wahyu Kuntjoro ◽  
Wisnoe Wirachman
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Aerodynamic Characteristic ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Moment Coefficient ◽  
Subsonic Wind Tunnel ◽  
Setting Angle ◽  
Blended Wing Body ◽  
The Moment

This paper presents a study on the effect of canard setting angle on the aerodynamic characteristic of a Blended Wing Body (BWB). Canard effects to BWB aerodynamic characteristics are not widely investigated. Hence the focus of the study is to investigate the variations of lifts, drags and moments when the angles of attack are varied at different canard setting angles. Wind tunnel tests were performed on BWB aircraft with canard setting angles,  ranging from -20˚ to 20˚. Angles of attack,  were varied from -10˚ to 10˚. Aspect ratio and canard planform area were kept fixed. All tests were conducted in the subsonic wind tunnel at Universiti Teknologi MARA, at Mach number of 0.1. The streamlines flow, at the upper surface of the canard was visualized using mini tuft. Result shows that the lift coefficient does not change much with different canard setting angles. As expected, the lift coefficient increases with increasing angles of attack at any canard setting angle. In general, the moment coefficient increases as the canard setting angle is increased. The results obtained in this research will be of importance to the understanding of aerodynamic behavior of BWB employing canard in its configuration.

Morphing wing with skin discontinuity – kinematic concept

2017 ◽  
Vol 89 (4) ◽  
pp. 535-546 ◽  
Author(s):  
Andrzej Tarnowski
Keyword(s):  
Wind Tunnel ◽  
Performance Optimization ◽  
Numerical Optimization ◽  
Design Methodology ◽  
Control Allocation ◽  
Flight Performance ◽  
Content Type ◽  
Original Contribution ◽  
Wing Morphing ◽  
Kinematic Solution

Purpose This paper aims to describe the concept of morphing tailless aircraft with discontinuous skin and its preliminary kinematic solution. Project assumptions, next steps and expected results are briefly presented. Design/methodology/approach Multidisciplinary numerical optimization will be used to determine control allocation for wing segments rotation. Wing demonstrator will be fabricated and tested in wind tunnel. Results will be used in construction of flying model and design of its control system. Flight data of morphing demonstrator and reference aircraft will result in comparative analysis of both technologies. Findings Proposed design combines advantages of wing morphing without complications of wing’s structure elastic deformation. Better performance, stability and maneuverability is expected due to wing’s construction which is entirely composed of unconnected wing segments. Independent control of each segment allows for free modeling of spanwise lift force distribution. Originality/value Nonlinear multipoint distribution of wing twist as the only mechanism for control and flight performance optimization has never been studied or constructed. Planned wind tunnel investigation of such complex aerodynamic structure has not been previously published and will be an original contribution to the development of aviation and in particular to the aerodynamics of wing with discontinuous skin.

scholarly journals Performance of Cell Phone Controlled Model Vehicle

2020 ◽  
pp. 14-20
Author(s):  
János Hegedűs-Kuti ◽  
Mátyás Andó
Keyword(s):  
Power Consumption ◽  
Cell Phone ◽  
Total Weight ◽  
Maximum Speed ◽  
Electronic Components ◽  
Additive Technology

The objective of the project was to construct a model car - using additive technology - which is connected to a phone via cordless communication. PLA was used as a material to print the units. The total weight of the model car is 690 grams including the electronic components. The power consumption and driving properties were measured under given circumstances. Based on our calculations, even in active use at its maximum speed of 5.16 km/h, the system is capable of at least 3.9 hours of operation, while full charging takes only 3 hours. As a result, with two battery units it can be operated continuously.

Design and experimental validation of a specialized pressure-measuring rake for blended wing body aircraft’s unconventional inner flow channel

2020 ◽  
Vol 234 (15) ◽  
pp. 2186-2196
Author(s):  
Xin Xu ◽  
Dawei Liu ◽  
Keming Cheng ◽  
Dehua Chen
Keyword(s):  
Wind Tunnel ◽  
Design Method ◽  
Wind Tunnel Test ◽  
Numerical Results ◽  
Flow Channel ◽  
Test Results ◽  
Complex Flow ◽  
Air Intake ◽  
Blended Wing Body ◽  
External Flows

The internal drag of the unconventional inner flow channel of blended wing body aircraft must be measured accurately to correct the air intake effect of the blended wing body flow-through model in wind tunnel tests. In this study, the pressure distribution of the inner flow channel under the interaction of internal and external flows was obtained through numerical simulation. A specialized pressure-measuring rake was designed based on the numerical results, and a validation test was conducted in a 2.4 m × 2.4 m transonic wind tunnel. Compared with the flow in traditional inlets/nozzles, the flow in the unconventional inner channel in the current research is asymmetric, the distortion index is higher, and the internal drag is more sensitive to flow changes. The wind tunnel test results have a good correlation with the numerical results, and the repeatability of the test results is satisfactory, indicating that the measurement accuracy and precision of the pressure-measuring rake are acceptable. The design method of the specialized rake is feasible, and it can be used to guide the measurement of complex flow in unconventional inner flow channels of blended wing body aircraft.

scholarly journals Simulation and flight experiments of a quadrotor tail-sitter vertical take-off and landing unmanned aerial vehicle with wide flight envelope

2018 ◽  
Vol 10 (4) ◽  
pp. 303-317 ◽  
Author(s):  
Ximin Lyu ◽  
Haowei Gu ◽  
Jinni Zhou ◽  
Zexiang Li ◽  
Shaojie Shen ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Unmanned Aerial Vehicle ◽  
Wind Tunnel Test ◽  
Small Scale ◽  
Level Flight ◽  
Flight Envelope ◽  
Aerial Vehicle ◽  
Attitude Controller ◽  
And Control ◽  
Thrust And Torque

This paper presents the modeling, simulation, and control of a small-scale electric powered quadrotor tail-sitter vertical take-off and landing unmanned aerial vehicle. In the modeling part, a full attitude wind tunnel test is performed on the full-scale unmanned aerial vehicle to capture its aerodynamics over the flight envelope. To accurately capture the degradation of motor thrust and torque at the presence of the forward speed, a wind tunnel test on the motor and propeller is also carried out. The extensive wind tunnel tests, when combined with the unmanned aerial vehicle kinematics model, dynamics model and other practical constraints such as motor saturation and delay, lead to a complete flight simulator that can accurately reveal the actual aircraft dynamics as verified by actual flight experiments. Based on the developed model, a unified attitude controller and a stable transition controller are designed and verified. Both simulation and experiments show that the developed attitude controller can stabilize the unmanned aerial vehicle attitude over the entire flight envelope and the transition controller can successfully transit the unmanned aerial vehicle from vertical flight to level flight with negligible altitude dropping, a common and fundamental challenge for tail-sitter vertical take-off and landing aircrafts. Finally, when supplied with the designed controller, the tail-sitter unmanned aerial vehicle can achieve a wide flight speed envelope ranging from stationary hovering to fast level flight. This feature dramatically distinguishes our aircraft from conventional fixed-wing airplanes.

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