Wyniki wyszukiwania - BazTech

1

Deficiency-surplus transition function (DeSuTra) in semi-empirical formulas for tumbling of freely falling card

Vorohobovs Vladimirs, Kleinhofs Martins

Composites Theory and Practice

|

2022

|

R. 22, nr 2

92--98

EN

A new phenomenological method for composing analytical formulae to describe dynamic systems using the DeSuTra function as a building block is introduced. Based on heuristic considerations, it is possible to write a correct formula with several unknown coefficients. Next, these coefficients are tuned such a way that the result coincides with the experimental data. To illustrate the viability of such a method, a simple but not trivial aerodynamic system was chosen: the autorotation of a rectangular piece of paper that falls in air. Three correction coefficients (diminishers) were introduced to calculate its rotation frequency Then a simple expression for the Magnus effect and drag force was used. All the obtained formulae were experimentally proved and the coefficients calculated. The conclusions drawn confirm the usefulness of the presented calculation procedure for the design of composites with chaotically distributed reinforcements.

2

Comparative Analysis of Effect of Wind Loads with Variation in Altitude and Angle of Inclination of Wind Direction on Solar Panels

Surendra Reddy P., Swapna K., Kiran Kumar G., Krishna Varma K. P. V.

Ecological Engineering & Environmental Technology

|

2021

|

Vol. 22, iss. 6

61--68

EN

Solar panels are used in wide range of applications like power generation, automobiles, electronic devices etc. They are trending devices which develop power from abundantly available solar energy. In spite of this advantage, they are affected by wind loads, which result in wind induced loading. Determining this is very essential because, the drag and lift forces applied on the solar panels due to the wind loads play a crucial role in the accomplishment of performance in the solar panels. In this work, an attempt was made to carry out a comparative analysis of the effect caused by the wind forces on different array sizes, altitudes, orientation of the solar panels at different wind speeds (5 m/s, 25 m/s) and at different inclination angles the wind (0°, 45°, 135° and 180°. The ultimate objective of this work was to analyze the effect caused by wind forces based on these combinations of the parameters. Different shapes of solar panels like rectangular and hexagonal shaped were analyzed for normal and optimized conditions. Moreover, wind load analysis was carried out for different altitudes like on the ground and on the roof top. The outcomes depict that the wind forces on front region of the conventional solar panels is higher when compared to the optimized solar panel.

3

Review of Selected Methods for Increasing the Aerodynamic Force of the Wing

Gnapowski Ernest

Advances in Science and Technology. Research Journal

|

2019

|

Vol. 13, no 1

60--67

EN

The manuscript presents the methods of increasing the aerodynamic force of the airfoil, currently used in aviation, and the directions of further research development. Currently, several methods are known and used to increase the aerodynamic force of the airfoil. The most widespread ones include wing mechanization systems, among others, flaps and slats. The non-mechanical elements of the wing construction that enable to increase the carrying force are used as well, among others; wing cuffs, vortilons, vortex generator. Research is being carried out on the introduction of mechanical elements that increase the lift force (Continuous Trailing Edge Flap, Morphing Wing), as well as non-mechanical elements such as plasma actuators. The manuscript describes the selected non-mechanical and mechanical elements currently used to increase the lift and the directions for the development of further research on increasing the aerodynamic force.

4

Plasma Actuator with Two Mesh Electrodes to Control the Flow Boundary Layer

Gnapowski Ernest

Advances in Science and Technology. Research Journal

|

2019

|

Vol. 13, no 2

31--37

EN

The manuscript presents selected designs of Dielectric Barrier Discharge (DBD) plasma actuators used to control the flow of the boundary layer on the surface of the wing. The principle of DBD plasma actuator operation and the process of the “ion wind” formation are presented. The manuscript presents the results of the tests carried out on the sash model with the SD 7003 profile and a DBD plasma actuator with two mesh electrodes, for which tests were carried out and tunnel images were recorded.

5

CFD analysis of the air flow around the blades of the vertical axis wind turbine

Gavgali M. M., Czyż Z., Czarnigowski J.

Journal of Technology and Exploitation in Mechanical Engineering

|

2017

|

Vol. 3, nr 1

1--7

EN

The paper presents the results of calculations of flow around the vertical axis wind turbine. Three-dimensional calculations were performed using ANSYS Fluent. They were made at steady-state conditions for a wind speed of 3 m/s for 4 angular settings of the three-bladed rotor. The purpose of the calculations was to determine the values of the aerodynamic forces acting on the individual blades and to present the pressure contours on the surface of turbine rotor blades. The calculations were made for 4 rotor angular settings.

PL

W pracy przedstawiono wyniki obliczeń opływu wirnika turbiny wiatrowej o pionowej osi obrotu. Trójwymiarowe obliczenia wykonano za pomocą programu ANSYS Fluent. Obliczenia przeprowadzono w warunkach stacjonarnych dla prędkości wiatru równej 3 m/s dla 4 ustawień kątowych wirnika z trzema łopatami. Celem przeprowadzonych obliczeń było określenie wartości składowych siły aerodynamicznej działającej na poszczególne łopaty oraz przedstawienie konturów ciśnienia na powierzchni łopat wirnika turbiny. Obliczenia przeprowadzono dla 4 ustawień kątowych wirnika.

6

Air flow analysis around the autogyro fuselage

Czyż Z., Ilhan I., Akcay M., Czarnigowski J.

Journal of Technology and Exploitation in Mechanical Engineering

|

2017

|

Vol. 3, nr 1

13--20

EN

The paper presents the results of the simulation of the air flow around the gyroplane without the influence of the rotor and pusher propellers. Three-dimensional calculations were performed using ANSYS Fluent software. Based on the calculations, the values of the drag force and the lift force on each component of the rotorcraft were determined. Based on the results obtained, the effect of angle of attack on the aerodynamic forces was obtained.

PL

W pracy przedstawiono wyniki symulacji opływu modelu wiatrakowca bez wpływu wirnika nośnego oraz śmigła pchającego. Trójwymiarowe obliczenia wykonano za pomocą programu ANSYS Fluent. Na podstawie przeprowadzonych obliczeń wyznaczono wartości siły oporu oraz siły nośnej działające na poszczególne części składowe statku powietrznego. W oparciu o uzyskane wyniki otrzymano wpływ kąta natarcia na siły aerodynamiczne.

7

Experimental determination of aerodynamic characteristics of the plane's wing with the volume generators

Lemko O. L., Molodchyk A., Predachenko K.

Prace Instytutu Lotnictwa

|

2016

|

Nr 4 (245)

79--86

EN

This paper is devoted to the results of studies in a wind tunnel model aircraft mounted with the vortex generators on the wing leading edge. The article presents away to improve the aerodynamic characteristics with vortex generators on the leading edge in the direct flow. It is shown that the vortex generators increase the lift force and the critical angle of attack due to the impact of large-scale vortices on the flow separation. Experimental data of studies of the wing in the wind tunnel showed rationality of use of volume generators - there usage enlarges the range of flight angles of attack and significantly increases lift-to-drag ratio.

PL

Niniejsza praca poświęcona jest wynikom badań w tunelu aerodynamicznym modelu samolotu wyposażonemu w generatory wirów na krawędzi natarcia skrzydła. W artykule przedstawiono sposób na poprawę właściwości aerodynamicznych samolotu z generatorami wirów na krawędzi natarcia w bezpośrednim strumieniu powietrza. Wykazano, że generatory wirów prowadzą do zwiększenia siły nośnej i krytycznego kąta natarcia z powodu wpływu dużych wirów na rozdzielenie przepływu. Dane doświadczalne badania skrzydła w tunelu aerodynamicznym wykazały, racjonalność wykorzystania generatorów wirów. Wykorzystanie powiększa zakres kątów natarcia i znacznie zwiększa współczynnik siły nośnej.

8

FCFD analysis of the influence of winglets on the aerodynamic performance of the DA42 Diamond aircraft

Szczepaniak R., Pożoga Ł., Stabryn S., Stryczniewicz W.

Journal of KONES

|

2016

|

Vol. 23, No. 1

361--368

EN

The paper presents the application of Computer Aided Engineering software for an investigation of the aerodynamic performance of a small two-engine aircraft. In the presented study, the Computational Fluid Dynamics was applied in order to determine the influence of winglets on the aerodynamic performance of the DA42 Diamond aircraft. The numerical simulations were performed with the use of SolidWorks Flow Simulation software. In order to evaluate the influence of the winglets on the lift and drag force, two configurations of the selected aircraft were modelled: with and without winglets. The results of CFD simulations confirmed a reduction of induced drag caused by wingtips vortices dissipation introduced by winglets. The maximum reduction of the induced drag was achieved at high angles of attack. The authors visualized the structure of vortices in case of wings with and without winglets. A smaller volume of wingtip vortices in case of winglets application can be seen in the pressure distribution and streamline plots. The outcome of the presented work confirms the feasibility of Computer Aided Engineering for the assessment of aerodynamic performance of aircraft. The presented methodology can be used in the process of designing and optimisation of alternative configurations of aircraft. The results of work might prove useful for DA42 DIAMOND pilots and maintenance personnel as well as for educational purposes.