Investigation of the Physical and Mechanical Properties of ABS Plastic for the Additive FDM Process in the Manufacture of Models for Experiments in Wind Tunnels

Work has been carried out to determine the physical and mechanical properties of ABS plastics for the manufacture of aerodynamic models using the additive technology of layer-by-layer synthesis FDM for testing in wind tunnels. The samples were tested at normal and negative temperatures. The features of the structure of the samples and the features of their destruction are revealed. The possibility of using ABS plastic for the manufacture of various models used in experiments in wind tunnels is evaluated.

A Novel Method that uses Light to Test Aerodynamics

Aerodynamics is a very important topic which has uses in a wide array of fields and is involved in things that range from bridges to spacecrafts. Despite this, most aerodynamic tests are performed only one of two ways, using extremely expensive wind tunnels or by using CFD (computational fluid dynamics) simulation. Both of these preexisting methods have flaws however, with wind tunnels costing gargantuan amounts of money and CFD methods consuming large amounts of energy. These flaws have prompted scientist and engineers to actively seek new solutions and methods that will help to address the cost and energy issues associated with the other two methods. This search has been to no avail so far as new novel methods have not been found until now. I have found a new method that concerns the use of light in order to test the aerodynamics of objects. To prove the feasibility, I have experimented using this method and have found it to accurately simulate aerodynamics behavior in all cases tested by me. This discovery is rather significant as it would lead to a substantial shift in the field of testing aerodynamics.

Methodology for calculating the efficiency of the rudders of the tandem aircraft

As of recent rapid development in the field of UAVs, unusual aerodynamic practices can be used, for example, the tandem scheme. In early planning stages, it’s important to evaluate aerodynamic characteristics of the chosen scheme and to approximate its balancing losses, as it impacts the stability and controllability of the craft. The most effective way of aerodynamic characteristics analysis is done using wind tunnels. However, it requires considerable investments in both financial terms and time, when designing the model, conducting the experiment and processing the results. Because of that, it’s worthwhile to consider the simple CFD calculations (XFOIL). This paper calculates aerodynamic characteristics of a tandem-scheme based “A-8” aircraft using XFLR5 analysis tool with the results compared to a real wind tunnel experiment. The overall conclusion of the paper is a recommendation to consider XFLR5 for early planning stages for advanced balancing losses calculation approximation.

Software complex for aircraft characteristics calculation

The article describes the method of calculating the aerodynamic loads of the aircraft, which can be programmed within the graphic user interface. The method uses statistical data of typical aerodynamic profiles flow in wind tunnels and mathematical expressions that describe the known laws of aerohydromechanics. The graphic user interface is tested by a model of the famous Ukrainian aircraft A32 that manufactured by Aeropract company. A surface model of the aircraft for modeling consists of the theoretical surface for the wing and the fuselage. A comparison of the formula’s calculation in the graphical interface and finite element calculations is given. The software interface is built in C #.

CRITICAL REVIEW OF MODERN NUMERICAL MODELLING OF SNOW ACCUMULATION ON ROOFS WITH ARBITRARY GEOMETRY

The calculation of snow loads on roofs of buildings and structures with arbitrary geometry is a complex problem, solving which requires simulating snow accumulation with acceptable engineering accuracy. Experiments in wind tunnels, although widely used in recent years, do not allow to reproduce the real full-scale effects of all snow transport subprocesses, since it is impossible to satisfy all the similarity conditions. This situation, coupled with the continuous improvement of mathematical models, numerical methods, computer technologies and related software, makes the development and future implementation of numerical modelling in real construction practice and regulatory documents inevitable. This paper reviews currently existing mathematical models and numerical methods used to calculate the forms of snow deposits. And, although the lack of significant progress in the field of modelling snow accumulation still remains one of the major problems in CFD, use of existing models, supported by field observations and experimental data, allows to reproduce reasonably accurate snow distributions. The importance of the “symbiosis” between classical experimental methods and modern numerical models is specifically emphasized in the paper, as well as the fact that only the joint use of approaches can comprehensively describe modelling of snow accumulation and snow transport and provide better solutions to a wider range of problems.

AERODYNAMIC STABILITY OF BRIDGES WITH VARIOUS LEVELS OF STRUCTURAL DAMPING

Introduction: Structural damping is one of the most important parameters affecting the aerodynamic stability of bridge structures. Purpose of the study: We aimed to assess the effect that structural damping of a bridge structure has on its stability in a wind current. Methods: In the course of the study, we performed experimental studies of the aerodynamic stability in typical girder bridge structures (with two and four main girders) with different levels of structural damping, facilitated by a unique experimental unit: Large Research Gradient Wind Tunnel, courtesy of the National Research Moscow State University of Civil Engineering (NRU MGSU). Results: The results of the experimental studies show that, despite the general trend towards the decrease in the amplitude of bridge span structure oscillations as the structural damping level increases, the dependence between these parameters is nonlinear. When providing R&D support in the design of real-life structures, in case it is necessary to increase the aerodynamic stability of the superstructure by increasing the level of structural damping (changing the type of joints in structural elements, using mechanical damping devices), it is recommended to conduct experimental studies in wind tunnels to assess the effectiveness of a given solution.

Transonic industrial wind tunnel testing in the 2020s

Wind tunnels remain an essential element in the design and development of flight vehicles. However, graduates in aerospace engineering tend to have had little exposure to the demands of industrial experimental work, particularly at high speed, a situation exacerbated by a lack of up-to-date reference material. In an attempt to fill this gap, this paper presents an overview of the current and near-term status and usage of transonic industrial wind tunnels. The review is aimed at recent entrants to the field, with the aim of helping them make the step from research projects in small university facilities to commercial projects in large industrial facilities. In addition, a picture has emerged from the review that contradicts received wisdom that the wind tunnel is in decline. Globally, the industrial transonic wind tunnel is undergoing somewhat of a renaissance. Numbers are increasing, investment levels are rising, capabilities are being enhanced, and facilities are busy.