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EN
This paper presents part of the investigation into aerodynamics of the vertical take-off and landing multirotor. There are described the technology to design a research object and the Particle Image Velocimetry (PIV) setup to measure airflow around the aircraft. The around-the-aircraft speed distribution was investigated for an angle of attack of 0o and for four different configurations. The results are presented in form of vector velocity field of airflow on the plane of symmetry of the test object. The results enabled the characteristics of speed vs. the distance from the fuselage. It was observed that the push propeller and the main rotor impact the speed field around the fuselage.
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Selecting appropriate materials is presently a complex task as material databases cover tens of thousands of different types of materials. Product designing proceeds in numerous stages and in most of them there are open questions with not only one correct solution but better and worse ones. This paper overviews the Diesel engine body construction materials mentioned in the literature and discusses a certain practical method to select materials for a cylinder head and a Diesel engine block as a prototype. The engine body, depending on its purpose, is most frequently iron or aluminum. If it is important to optimize parts to achieve low weight, aluminum alloys are usually applied, especially in the automotive and aviation industries. In the latter case, weight is even more important so new types of magnesium alloys which are even lighter than aluminum ones are developed and used. However, magnesium alloys are, for example, more flammable and not enough strong so, for safety reasons, this type of material is not used solely in engine bodies.
EN
The work presents a three-dimensional modeling of air flow around the research object. The purpose of this work was to perform numerical calculations to identify the magnitude of the aerodynamic drag force generated on individual elements of a high energy efficiency vehicle body. This vehicle, specially designed for the Shell Eco-marathon competition, needs to show the lowest possible fuel consumption while maintaining the prescribed speed. Minimizing the drag force at an early designing stage plays an important role here. The calculations were performed using the ANSYS Fluent calculation solver. The result of the conducted research is a description of the velocity and pressure distributions around the tested vehicle as well as an identification of the drag force on the external surfaces of the components and a description of the relationship between them. The work also discusses the dependence of the drag force as a function of speed in the range from 0 to 12 m/s. The influence of the ground on the drag force in the case when the object was immobilized in relation to the walls at the flowing medium, as in a wind tunnel, was investigated. On the basis of the calculations performed, no impact of the ground on the generated drag force magnitude was found.
EN
The aerodynamics of powerboats used in inshore powerboat racing has a significant impact on their performance. The aerodynamic drag forces generated on individual elements of this type of boats were tested. The solid model of the boat developed in the CAD software was used for the calculations. The computational grid was generated, as well as the boundary conditions and the turbulence model, were determined. On the basis of such assumptions, the numerical calculations were carried out using the CFD method. The results from the numerical simulations consist of a description of the velocity and pressure distribution around the tested object and identification of the drag force on the components of the powerboat with a description of the relationship between them. Additionally, the variation of the drag force as a function of speed in the range from 0 to 60 m/s was presented. The tests were performed for 5 values of the angle of attack of the boat to the surface of water in the range from 0° to 12°. The scope of the research allowed for the development of a drag force map depending on the defined parameters. The test results can be used to optimize the shape of the boat structure in order to reduce the aerodynamic drag generated on its individual elements.
EN
The study involved a numerical analysis of the water dropping process by fixed-wing aircraft. This method, also known as air attack, is used for aerial firefighting, primarily in green areas such as forests and meadows. The conducted calculations allowed for the analysis of the process over time. The calculations were performed based on a SolidWorks model of the M18B Dromader aircraft. After defining the computational domain and setting the boundary conditions, the simulations were carried out using the ANSYS Fluent software. The resulting water dropping area was used to analyze the intensity of water distribution. The volumetric distribution and airflow velocity distribution were analyzed for specified time steps. The boundary layer where air no longer mixes with water during the final phase of water dropping was also determined. The obtained results provide an important contribution to further analyses aimed at optimizing the water dropping process by fixed-wing aircraft.
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The paper presents the numerical analysis of the drag force generated on the body of a sports car, based on the CFD method in the Ansys Fluent program. The three-dimensional model of the vehicle was taken from an open CAD database. Based on this, a computational grid was developed, boundary conditions and a turbulence model were defined. As a result of the calculations, the pressure distribution on the individual body parts and the velocity distribution in selected cross sections were obtained. In the next part of the research, the simulation results are used to optimize the shape of the bodywork of different passenger vehicles in order to reduce the generated drag force.
EN
The paper presents the authors’ method and test rig for performing the deformation analysis of unmanned aircraft fuselages. To conduct the analysis, the DIC system was used, as well as a test rig designed and constructed by the authors, equipped with a dedicated control and load control system. The article presents a description of the research capabilities of the test rig developed for testing the deformation of unmanned aircraft fuselages. Due to the specific operating conditions of the designed fuselage,the test rig developed allows the simulation of loads corresponding to different flight conditions. In addition, it is possible to change the forces acting on the fuselage simultaneously for all servos or each of them separately. Finally, results showing the displacement of component control points for the considered fuselage versions are presented. The tests carried out using the developed test rig allowed the verification of the maximum deformations. The two versions of the composite fuselage of an aerial vehicle have been compared in the paper. The created measurement system and performed analyzes have enabled us to identify and quantitatively analyze the weaknesses of the construction. The results have enabled us to geometrically modify the constructionso the mass of the fuselage reduced by 19% and a coefficient of construction balance increased by 22%.
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