Editorial

The special issue “Emerging Aerospace Technologies in Aerodynamics, Propulsion, and Materials” is published which covers the aerospace domain covering aerodynamics, propulsion, and materials used for aeronautical and aerospace domains. In this issue, the authors have focused on the articles related to experimental and computational work related to aircraft performance, aircraft stability and control, materials, and some other important areas. Most of the papers are based on Project Based Learning which is one of the research-oriented teaching-learning processes recently introduced in National Education Policy 2020 by the Government of India

Advancements in UAVs-A review

ABSTRACT: Present decade has been observed that Unmanned Aerial Vehicles(UAVs) are occupying the sky to accomplish different missions. They became the popular area of interest due to their growing utility and relative cost. Increased demand of UAVs allowing the researchers for the optimized UAV as a major area of interest. They are providing new and better opportunities to cellular networks. UAV industry is undergoing a huge amount of advancements in it such as in navigation system, privacy and security ,mission management system, power system communication system etc. this article mainly focuses on the advancements regarding privacy and security of UAVs ,mission management system. The motivation behind the development of strategies for defending the breaches caused by data protection and public safety them are examined. This study gives an overview about past and how the present usage of UAVs is optimized by implementing the defense techniques. The major six criteria implemented to defend socio-technical concerns are explained. Few countries which adapted these regulations are discussed briefly .Ensuring security of the UAV system is studied considering physical security and cyber security as major aspects. The study also provides the techniques to defend these security threats. on Mission planning and mission management

FLOW ANALYSIS ON DELTA WING – A REVIEW

Many aircraft, like fighters and bombers, are delta-winged aircraft. These aircraft have the characteristics of producing a greater lift at very small angles of attack even at very low Reynold’s number. Highly swept-wing aircraft experience greater lift due to the generation of the leading-edge vortex at a high angle of attack flight. The phenomena of vortex breakdown are noticed which leads to the reduction of the vortex lift and leads to the instability of the aircraft. This paper deals with an analysis of the flow on the delta wing with the existing literature and compares its benefits over the conventional wings using experimental and computational methods. The critical angles, pressure, and velocity variations are observed along with chord and spanwise locations

Effect of Twin Vertical Stabilizers on Lateral Directional Static Stability of an Aircraft – A Computational Study

The advantages of twin vertical Stabilizers over a single vertical Stabilizer of an aero plane are the rationale for this study. For conventional aero planes, the use of double vertical Stabilizers is being considered. The contribution to lateral stability has been examined for this application. XFLR5 software was used to conduct the overall analysis. The analysis was conducted for a single vertical Stabilizer as well as twin vertical Stabilizers, and the findings were compiled and correlated. It is critical to be able to fully explain and evaluate the stability and control parameters. It is crucial to understand the relationship between the aerodynamics of the airframe and its stability characteristics in order to increase flight endurance and deployment effectiveness. The stability analysis based on the dynamic model of the twin boom vertical Stabilizer is presented in this paper. The lateral-directional stability of an aero plane with a single vertical tail is determined to be 20% more efficient than that with twin boom vertical Stabilizers. The trim condition is moderately satisfied by an aircraft with twin vertical Stabilizers

Detecting Human-Object Contact in Images

Humans constantly contact objects to move and perform tasks. Thus, detecting human-object contact is important for building human-centered artificial intelligence. However, there exists no robust method to detect contact between the body and the scene from an image, and there exists no dataset to learn such a detector. We fill this gap with HOT ("Human-Object conTact"), a new dataset of human-object contacts for images. To build HOT, we use two data sources: (1) We use the PROX dataset of 3D human meshes moving in 3D scenes, and automatically annotate 2D image areas for contact via 3D mesh proximity and projection. (2) We use the V-COCO, HAKE and Watch-n-Patch datasets, and ask trained annotators to draw polygons for the 2D image areas where contact takes place. We also annotate the involved body part of the human body. We use our HOT dataset to train a new contact detector, which takes a single color image as input, and outputs 2D contact heatmaps as well as the body-part labels that are in contact. This is a new and challenging task that extends current foot-ground or hand-object contact detectors to the full generality of the whole body. The detector uses a part-attention branch to guide contact estimation through the context of the surrounding body parts and scene. We evaluate our detector extensively, and quantitative results show that our model outperforms baselines, and that all components contribute to better performance. Results on images from an online repository show reasonable detections and generalizability

Aerodynamic characteristics of owl like airfoil at low reynolds number

The computational investigation of aerodynamic characteristics and flow fields of a smooth owl-like airfoil without serrations and velvet structures.The bioinspired airfoil design is planned to serve as the main-wing for low-reynolds number aircrafts such as (MAV)micro air vechiles.The dependency of reynolds number on aerodynamics could be obtained at low reynolds numbers.The result of this experiment shows the owl-like airfoil is having high lift performance at very low speeds and in various wind conditions.One of the unique feature of owl airfoil is a separation bubble on the pressure side at low angle of attack.The separation bubble changes location from the pressure side to suction side as the AOA (angle of attack) increases. The reynolds number dependancy on the lift curve is insignificant,although there’s difference in drag curve at high angle of attacks.Eventually, we get the geometric features of the owl like airfoil to increase aerodynamic performance at low reynolds numbers

EXPERIMENTAL ANALYSIS OF DOUBLE BOX WING UAV.

ABSTRACT In an attempt to reduce the induced drag on a wing, Prandtl found that induced drag reduced significantly by highly increasing the number of vertically offset wings. The same result could be obtained by joining the wingtips of two vertically offset wings. This helped increase payload capacity and also reduced fuel consumption and emissions. Such a wing configuration came to be known as Prandtl’s box wing. In this work, the design and analysis of a box wing aircraft model has been carried out. The preliminary analysis is performed using XFLR5, and the computational analysis is done with the help of ANSYS 18.2. The values of experiments are computed with the help of MATLab R2017. The box wing model has shown a nearly 53.74% reduction in drag as compared with conventional wing models. The computational results of drag have been compared and validated with the results of analytical and the experimental results from the wind tunnel and found to be within 10% of the computational result. Since the drag of the box wing is significantly lesser than the conventional wings the box wing is a feasible configuration which can be used to design various aircrafts including Unmanned Aerial Vehicles and Commercial Planes

Three-Dimensional Flow Analysis over Canard Configuration in Turbulence Model

The canard has been seen as an ominous aerodynamic object for ages this paper is to shed some more light on the effects of canard configuration on the aircraft’s wings. This flow-field analysis is thus being done using a turbulence model solution to take into the effects of a real-time environment where the vortices from the canard are captured more accurately. The analysis has been done meticulously and made to be as error-free as possible under the guidance of Dr. Yagya Dutta Dwivedi

EFFECT OF VARIABLE CANT ANGLE ON SWEEPBACK WING

Winglets are commonly used drag-reduction and fuel-saving technologies in today’s aviation. The primary purpose of the winglets is to reduce the lift-induced drag, therefore improving fuel efficiency and aircraft performance. Traditional winglets are designed as fixed devices attached at the tips of the wings. However, because they are fixed surfaces, they give their best lift-induced drag reduction at a single design point. In this work, we propose the use of variable cant angle winglets which could potentially allow aircraft to get the best all-around performance (in terms of lift-induced drag reduction), at different angle-of-attack values. This paper describes a XFLR 3-dimensional winglets analysis that was performed on a wing of NACA2412 cross sectional airfoil. The wing has span 2.40 m, root chord 0.180 m, tip chord 0.110 m, sweep angle 5 degree and taper ratio 0.556 and for a winglet NACA 0024 cross-sectional airfoil was considered of max thickness 24 percent at 30 percent chord, max camber 0 percent at 0 percent chord. The present study shows effects of wing without winglet, wing with winglet at cant angle 30, 60, 90. The results obtained from the analysis demonstrate that by carefully adjusting the cant angle, the aerodynamic performance can be improved

Effect of Ground Proximity on Aerodynamic Characteristics of NACA 4412 Airfoil

Ground effect plays a vital role in modulating the flow behavior over any streamlined body. The most widely used wing-in ground effect (WIG) aircrafts and seaplanes utilize this phenomenon in order to enhance the aerodynamic performance during the landing and take-off phases of flight. This paper investigates the aerodynamics of ground effect on a NACA 4412 rectangular wing without end plates. The experiment was conducted in a low-speed wind tunnel at Re=2×105 for the ground clearance of 1 and 0.5 of the chord, measured from the maximum thickness position on the airfoil. The pressure distribution over the chord length was recorded for α=3° and 6° to verify the effect of ground clearance during takeoffs. The results have shown to be in good accordance with the literature, as the coefficient of lift augmented with increase in ground proximity and the induced drag was minimized