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AlainSat-1 is a remote sensing CubeSat carrying earth observation payloads developed by student teams from three international universities. Planned for launch in 2023 it is a direct result from the collaborative effort between the IEEE Geoscience and Remote Sensing Society (GRSS) and the National Space Science and Technology Center (NSSTC) at UAE University. CubeSats are popular among the research and academic communities as a space platform from which to perform related research and academic work connected to space technologies due to their compact size, shorter development time, and relatively low cost. However, because most CubeSats are built using off-the-shelf components, their capacity to resist the harsh environments of space must be proven. Aside from ensuring that structural criteria are met, thermal analysis is critical for ensuring that components or payloads stay functioning in extreme hot or cold environments. The thermal analysis results of AlainSat-1’s finite element model (FEM) functioning under the projected thermal environment associated to its mission are presented in this study. Preliminary results from the analysis using SIEMENS NX show that temperature measurements are within an acceptable range. However, more modification of the simulated environment and FEM in terms of mesh sizes and radiative and conductive thermal couplings is needed before conclusive results may be obtained. The approved simulated results and parameters will be tested experimentally in a Thermal Vacuum Chamber. In addition, challenges identified throughout the analysis and their remedies are discussed.

This paper presents the overall pros and cons of the effect of surface roughness elements over a NACA 4412 tapered, swept back half wing with a sweep angle of 30° and a dihedral angle of 5°. The tests were conducted at a Reynolds number of 4 × 105 in the IIUM Low Speed wind tunnel. Different roughness sizes and roughness locations were tested for a range of angle of attack. Lift, drag and pitching moment coefficients were measured for the smooth wing and with roughness elements. Surface roughness delays the stall angle and decreases the lift. The wing with the roughness elements located at 75% to 95% of mean chord from leading edge shows minimum drag and maximum lift compared to other locations. Significant increase in the pitching moment coefficient was found for flexible roughness elements. In case of rigid surface roughness, the effect on pitching moment is small

Directional stability characteristics explain the capabilities of a hybrid buoyant aircraft’s performance against the side wind, which induces flow separation that is chaotic in nature and may lead to oscillations of the aerodynamic surfaces. A numerical study is carried out to estimate the effect of side wind. The boundary conditions for the computational domain are set to velocity inlet and pressure outlet. Due to the incompressible flow at the cruise velocity, the density is taken to be constant. For these steady state simulations, the time is discretized in first order implicit and the SIMPLE scheme is employed for pressure velocity coupling alongwith k-ω SST model. Based on the results obtained so far, it is concluded that voluminous hybrid lifting fuselage is the major cause of directional.

Dorsal fin is used in swimming animals like shark for the generation of thrust as well as to meet the requirement of the lateral stability. In the case of aircraft, rudders are normally used for the said requirement. In the present work, this nature inspired idea is explored for its application to neutralize the unavoidable asymmetric thrust produced by the twin engines of a hybrid buoyant aircraft. First, the estimation of asymmetric thrust is obtained with the help of analytical techniques for maximum thrust condition at 4 degree angle of attack. The moment generated by it is utilized for the sizing of a dorsal fin which looks similar to a tapered wing and is placed aft of the center of gravity. Wind tunnel testing at subsonic speed is carried out to explore the design features of this rotatable dorsal fin. It is found that a small rotation of 5 degree can generate the required moment. However, such rotation requires a complete pneumatic/electro-mechanical system and an alternative of it is to use a cambered airfoil for the dorsal fin installed at fixed location. Such a flow controlling device can also be used as an antenna mast, which is commonly installed out the fuselage of the aircraft for communication purposes. Moreover, by incorporating this technique, a pilot doesn’t have to put an extra effort to make the aircraft stable in the presence of side wind.

Wing alone models are usually tested in wind tunnels for aerospace applications like aircraft and hybrid buoyant aircraft. Raw data obtained from such testing is subject to different corrections such as wall interference, blockage, offset in angle of attack, dynamic pressure and free stream velocity etc. Since the flow is constrained by wind tunnel walls, therefore special emphasis is required to deliberate the limitation of correction methods for blockage correction. In the present research work, different aspects of existing correction methods are explored with the help of an example of a straight semi-span wing. Based on the results of analytical relationships of standard methods, it was found that although multiple variables are involved in the standard methods for the estimation of blockage, they are based on linearized flow theory such as source sink method and potential flow assumption etc, which have intrinsic limitations. Based on the computed and estimated experimental results, it is recommended to obtain the corrections by adding the difference in results of solid walls and far-field condition in the wind tunnel data. Computational Fluid Dynamics technique is found to be useful to determine the correction factors for a wing installed at zero spacer height/gap, with and without the tunnel wall.

This paper reports the development and validation of a new questionnaire to assess students' perceptions of the online learning environment in Indonesia during the COVID-19 pandemic. In total, 669 participants (454 women, 215 men) from various universities were recruited online to complete a 25-item questionnaire. Item factor analysis verified a five-factor model, while multidimensional Rasch analysis showed that all items fit this model and have good reliability. The factors of Access, Interaction, Lecturer Support, Equity, and Investigation formed the valid and reliable Online Classroom Learning Environment Inventory (OCLEI). All aspects of online learning readiness were related to the five factors of the OCLEI, therefore supporting convergent validity. With these results, we concluded that the OCLEI is a novel measure that can be used in future educational research in Indonesia. Limitations and implications are noted.

The use and benefits of a strut-based wing on a transonic commercial transport airplane are compared with those of a conventional cantilever wing.

In this work, a study has been conducted to observe the influence of fuel weight distribution on the flutter characteristics of a high aspect ratio swept wing. In this paper, B777-200 wing model having a 34º sweptback angle is used as a baseline and two other models with the swept angles of 0º (straight wing) and 30º (forward swept) are considered in this study. Aeroelastic analysis is performed ranging from sea level up to 35,000 ft and the influence of in-flight fuel management in several flight altitudes is also investigated. There are four different fuel distribution model are investigated and it was found that some fuel distribution configuration are more critical which may lead to flutter. Moreover it was found that the flight altitude significantly affects the aeroelastic instability. [ABSTRACT FROM AUTHOR]

In the past decades, there has been a growing interest in unmanned aerial vehicles (UAVs) for educational, research, business, and military purposes. The most critical data for a flight system is the telemetry data from the GPS and wireless transmitter and also from the gyroscope and accelerometer. The objective of this paper is to develop a control system for UAV using long-range wireless communication and GPS. First, Matlab simulation was conducted to obtain an optimum PID gains controller. Then LoRa wireless was evaluated during clear and rainy days. Static and dynamic points measurement was conducted to validate and optimize GPS accuracy. GeoMapping in Matlab and Google GPS GeoPlanner were then used to analyze the traveled UAV flight path. [ABSTRACT FROM AUTHOR]