NUMERICAL AND EXPERIMENTAL ANALYSIS OF A CENTRIFUGAL PUMP WITH DIFFERENT ROTOR GEOMETRIES

The paper presents a comparative analysis of the operation of two variants of centrifugal pump rotors, a description of the main parameters, and the influence of the blade geometry on the performance characteristics obtained. Rotors have been designed using the arc and point method. Based on the developed 3D CAD models, the rotors were printed using the rapid prototyping method on a 3D printer in FFF (Fused Filament Fabrication) technology, in order to experimentally verify the performance, by placing them on the Armfield FM50 test stand. The analysis part of the CFD includes a fluid flow in Ansys Fluent. The process of creating a flow domain and generating a structural mesh was described, along with the definition of boundary conditions, the definition of physical conditions and the turbulence model. The distribution of pressures and velocities in the meridional sections is shown graphically. The chapter with the experimental analysis contains a description of the measuring stand and the methodology used. The results obtained made it possible to generate the characteristics, making it possible to compare the results received. The results allowed to note the influence of geometry on the behavior of the rotors during operation in the system and to indicate that the arc rotor gets a 7% higher head and 2% higher efficiency than the point method rotor, which gives the basis for its commercial use in industry

Comparative analysis of the friction coefficient of various airport pavements

Abstract: The parameter defined as the coefficient of friction is one of the basic parameters that are responsible for the characteristics of the surface on which vehicles (cars, aircraft) travel. The coefficient of friction is very important as it is responsible for the safety and relia- bility of the pavement. The paper below presents general issues concerning the friction force and its influence on the movement of aircraft on airport pavements. The requirements for the assessment of the friction coefficient were also discussed. Based on the results of tests carried out at four airports, an analysis of the decrease in the value of the friction coefficient was per- formed. Keywords: Friction; Runway; ASF

Analysis of flow through channel with mounted blades

Numerical analysis of parts of the installation for transporting the mixture. The mixture consists of sand, stones and water. The analysis concerns the possibility of reducing the flow velocity of the mixture in the installation by means of installing the blades. The article presents an analysis of 10 blades that have been simulated. Speed distributions are presented after passing through the blades and determined which slows the speed of the mixture to the best possible extent

Analysis of the Environmental Parameters of the GTM 400 Turbojet Engine During the Co-Combustion of JET A-1 Jet Oil with Hydrogen

The aim of the research was to determine the possibility of co-combustion of conventional aviation fuel (JET A-1 jet fuel) with hydrogen (H2). The tested miniature turbojet engine was adapted to co-combust of both fuels. The results obtained from the research provide a positive premise for the application and implementation of hydrogen co-combustion (or combustion) technology in aircraft turbojet engines, which has not yet found industrial application. Observations and research show that co-combustion of jet fuel with hydrogen helps reduce the carbon footprint of the use of turbojet aircraft engines and also reduces other harmful substances (e.g. carbon monoxide, nitrogen oxides or solid particles). During the tests, no deterioration of the engine's operating parameters was observed and the set operating parameters were maintained. To summarize, the technology of co-combustion or hydrogen combustion in miniature turbojet engines is an indicated direction in the development of pro-ecological aircraft engines

A control system that causes the check for obstruction of the ducts of seed metering

Even sowing of the seeds is very important because the quality of the crop depends on it. For this reason, the aim is to sow without a culvert caused by an obstruction of the seed hose. For this purpose, a patency control system has been developed for hoses that allow the seed to enter the ground. This allows to ensure the uniformity of seeding, which is very desirable nowadays. The developed method consists in mounting parallel sensors built into the head or on the output nozzles from the head and sensors in the coulters from which information will be transmitted to the monitoring system

Thermal Diffusivity of Concrete Samples Assessment Using a Solar Simulator

The thermal properties of pavement layers made of concrete with varying bulk densities are a particularly interesting topic in the context of development road technologies. If a hybrid layer system is used as a starting point, with thin asphalt layers (from 1 cm to 4 cm) laid on top of a foam concrete layer, thermal properties begin to play a crucial role. The main research problem was to create a test method enabling the assessment of the influence of solar heating on the thermal parameters of the building material, especially cement concrete. For this reason, this paper is concerned specifically with the assessment of a new methodology for testing and calculating the value of the thermal diffusivity coefficient of samples made of concrete varying bulk densities. In this case, using the proprietary concept the authors built a solar simulator using a multi-source lighting system. The analysis of the results of laboratory tests and numerical analyses allowed the authors to observe that there is a strong correlation between the bulk density of samples heated and the thermal diffusivity parameter, which appears in the unidirectional heat transfer equation. The strength of this relationship has been expressed with the coefficient of determination and amounts to 99%. The calculated values of the coefficient of thermal diffusivity for samples made of foam concrete range from 0.16×10−6m2s to 0.52×10−6m2s and are lower (from 2.5 to 8 times) than the value determined for samples made of typical cement concrete

Thermal Diffusivity of Concrete Samples Assessment Using a Solar Simulator

The thermal properties of pavement layers made of concrete with varying bulk densities are a particularly interesting topic in the context of development road technologies. If a hybrid layer system is used as a starting point, with thin asphalt layers (from 1 cm to 4 cm) laid on top of a foam concrete layer, thermal properties begin to play a crucial role. The main research problem was to create a test method enabling the assessment of the influence of solar heating on the thermal parameters of the building material, especially cement concrete. For this reason, this paper is concerned specifically with the assessment of a new methodology for testing and calculating the value of the thermal diffusivity coefficient of samples made of concrete varying bulk densities. In this case, using the proprietary concept the authors built a solar simulator using a multi-source lighting system. The analysis of the results of laboratory tests and numerical analyses allowed the authors to observe that there is a strong correlation between the bulk density of samples heated and the thermal diffusivity parameter, which appears in the unidirectional heat transfer equation. The strength of this relationship has been expressed with the coefficient of determination and amounts to 99%. The calculated values of the coefficient of thermal diffusivity for samples made of foam concrete range from 0.16×10−6m2s to 0.52×10−6m2s and are lower (from 2.5 to 8 times) than the value determined for samples made of typical cement concrete