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Reducing the mass of supersonic aerodynamic surfaces is a critical challenge in the development of high-speed rockets to further their potential range. This study presents the redesign of a supersonic fin with the primary objective of reducing its thickness from 25 mm. Two designs are investigated, with thicknesses of 10 and 12 mm, respectively, to ensure structural integrity under extreme flight conditions. A comprehensive computational approach is employed, combining static structural analysis, modal analysis, and aeroelastic analysis. Modal analysis is validated through an experimental method using a hammer impulse test for modal frequencies. The 10 mm rocket fin cannot withstand the static load simulated under the flight condition of 15-degree angle of attack, maximum operational flight speed of Mach 3.27, and air density at sea level. The 12 mm thick fin meets the requirements and demonstrates a flutter speed of Mach 11, significantly exceeding the required flutter speed of Mach 3.99. This research highlights the feasibility of substantial weight reduction in supersonic fins without compromising stability, offering a pathway for future advancements in lightweight, high-speed control surfaces.

Fluidic oscillators are used to overcome fluid flow separation on the upper side of the airfoil. The AoA chosen is for stall conditions, namely 16°, 18° and 20°. The type of fluidic oscillator used is a two-feedback channel fluidic oscillator. The chosen element is a triangle because it is easy to implement in complex geometries such as fluidic oscillators. The algorithm used is PISO. The governing equation for solving problems is URANS. URANS is then combined with the k-omega SST turbulence model. A low Reynolds number of 48000 was chosen to simulate the NACA 0015 airfoil. This Reynolds number is calculated based on the chord length of the airfoil. Variations were also made to the fluidic oscillator velocity-inlet value. The velocity-inlet variations given are 25 m/s, 35 m/s, and 45 m/s. The increase in Cl will be more significant if the selected inlet velocity is higher. At an inlet velocity of 45 m/s, the average increase produced was 38.53%. Double FO experienced an increase of 21.99%. Drag reduction is another parameter used to assess the aerodynamic performance of an airfoil. The average drag reduction for a velocity-inlet of 45 m/s is 12.54%. Double FO produces an average drag reduction of 6.80%.

The increase in FO frequency due to the use of BFS is accompanied by an increase in pressure losses. The study was conducted using the URANS governing equation and the SST k-ω turbulence model. Double BFS exhibited the highest frequency, with an average increase of 25.78% over the prototype. In contrast, the average frequency increases of single and triple BFS were 20.29% and 19.6%, respectively. The frequency increase is influenced by the momentum of the backflow in the feedback channel. Double BFS had a lower pressure loss than the prototype model, with 4.54% reduction. The average pressure loss of the single BFS model was 24.9% higher than that of the prototype model, whereas the triple BFS model showed a 0.039% increase. The pressure loss is influenced by the recirculation bubble in the FO chamber. Nondimensional analysis using Strouhal and Euler numbers also showed that double BFS exhibited the best performance. The prototype model and single BFS had a velocity profile shape that is closer to a homogeneous shape. The double and triple BFS exhibited a velocity profile shape that is closer to the bifurcated jet shape. Bifurcated jets, which exhibit a wider spread, are characteristic of oscillatory flows. Thus, it can be concluded that the double BFS FO is more recommended.

The existing UPM low speed wind tunnel was usually occupied by students, who carried out their final year projects or postgraduate researches, so that there was hardly free time slot for any additional testing work. Due to this reason, a new wind tunnel project has been started recently. Some basic specifications of the new tunnel have been pre-selected before the project was started, which comprised the following design decisions: a tunnel speed of 50 m/s, a test section area of 1´1 m2, and a closed circuit tunnel type. It wouldn’t be difficult to perceive that this pre-selection was made based on some of the trade-off results among the project’s options and constraints. This paper is aimed to present a simple analysis on the design of the new tunnel, focusing only on its basic geometries. Some design decisions that have been made related to its basic geometries are analyzed and reported in this paper. This analysis may be considered as a design verification of the new tunnel or even perhaps be regarded as scientific justification for its existence.

In Malaysia, there exist wind tunnels operated by several universities and organizations. Most of them are actively used for a variety of experimental works that are needed by uncounted educational curricula and aerodynamics related researches. Lately, wind tunnels have even become increasingly accepted as one of common engineering tools in solving of unexpected and abundant wind engineering problems that are continually facing automotive industries, oil and gas companies, as well as governmental agencies and ministries. This paper is meant to present an overview of the existing wind tunnels, accompanied with information on some important technical data, and added, to a lesser extent, with complementary information about backgrounds and design philosophies. The emphasis is, however, given only to those with test section size of 1.0 square meter or larger. From the general point of view, some information about testing capabilities and trends in wind tunnel technology is also presented.