Wyniki wyszukiwania - BazTech

1

Biopolymer based stabilization of Indian desert soil against wind induced erosion

Dagliya Monika, Satyam Neelima, Garg Ankit

Acta Geophysica

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2023

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Vol. 71, no. 1

503--516

EN

Wind-induced soil erosion is a major global misfortune, which obliterates nearly one-third of worldwide soil. The windswept sand particles cover large areas including highways, and make the visibility vague. This results in accidents, damaged infrastructure, delayed fights, and various health issues. The erosive impact of the wind can be minimized by enhancing the intactness of the soil surface. There is a prerequisite to adopt viable measures to strengthen soil against wind erosion. There are certain nature-based solutions that can fortify soil against wind erosion and the application of biopolymers is one of them. The objective of this study is to examine the viability of non-toxic biopolymers for stabilizing desert sand by improving its erosion resistance property and strength. In the present experiment, three biopolymers, sodium alginate (SA), pectin (P), and acacia gum (AG), were used with 1, 2, and 3% concentrations for 1 and 0.75 PV as stabilizing agents. The treatment with biopolymers was performed either by surficial treatment (spraying or pouring of solution) or by mixing and compact method based on the viscosity of prepared biopolymer solutions. The biotreated sand samples were tested in a wind tunnel at varying wind speeds of 10, 20, and 30 m/s to assess sand erosion. Surface strengths were assessed by measuring compressive strength using a pocket penetrometer. Crust thickness measurement was performed to check the penetration depth of biopolymer solution and binding of sand particles. All three biopolymers with 1% concentration gave a feasible solution for erosion against wind and binding of particles through SEM analysis. SA and P could not be sprayed for 2 and 3% concentrations due to high viscosity. This solution is also not feasible for the field application. Simultaneously, AG with 2 and 3% concentration was highly soluble, less viscous, and gave more surface strength due to higher percentage of biopolymer concentration.

2

Experimental study on Ahmed’s body drag coefficient

Wysocki Dominik, Szymanek Arkadiusz

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2022

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nr 25(1)

87--105

EN

The work presents an experimental designation of the aerodynamic drag coefficient for two configurations of the Ahmed body model, with slant angle of 25° and with the inactive synthetic jet generator. When analyzing the aerodynamic drag of vehicles, most authors focus on higher Reynolds numbers, describing lower values only by designated trend lines. Which is why the main contribution of this experimental work was to designate the Ahmed’s body drag coefficient for low Reynolds numbers and to verify the obtained results with other authors experiments especially with the trend lines for Reynolds number in the range 0,35x105 – 1,8x105. For data taken from the literature, it can be seen that the value of the drag coefficient for the Ahmed body model decreases when the Reynolds number increases. The results obtained during the experiment show the opposite tendency.

3

Experimental Study of Air-Assisted Rocket System Models for Launching Payloads into a Low Earth Orbit

Frant Michał, Majcher Maciej, Omen Łukasz, Zalewski Piotr

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2022

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Vol. 13, Nr 3 (49)

67--82

EN

This paper presents the results of aerodynamic testing of air-launch rocket kit models for launching payloads into a low Earth orbit. The work was performed in a low-speed wind tunnel at the Military University of Technology (MUT, Warsaw, Poland)), using symmetrical airflow. Two carrier aircraft models were tested, i.e., Su-22 and MiG-29 aircraft without launched payloads and with these payloads at a dynamic pressure of q = 500 [Pa] and the range of angles of attack at α = -28° ÷ 28°. The values obtained related to the aerodynamic drag coefficient, aerodynamic lift coefficient, pitching moment coefficient and lift to drag ratio, and are given in tabular and graphic forms. The tests were primarily used to validate the numerical results obtained during implementation of the project “Air-assisted rocket system for launching payloads into low Earth orbit - feasibility study”.

PL

W pracy przedstawiono wyniki doświadczalnych badań aerodynamicznych modeli lotniczo-rakietowych zestawów do wynoszenia ładunków na niską orbitę okołoziemską. Badania wykonano w tunelu aerodynamicznym małych prędkości WAT w opływie symetrycznym. Zbadano dwa modele nosicieli – Su-22 oraz MiG-29 bez wynoszonych ładunków oraz z wynoszonymi ładunkami przy ciśnieniu dynamicznym q = 500 [Pa] w zakresie kątów natarcia α = -28° ÷ 28°. Uzyskane wartości współczynnika oporu aerodynamicznego, współczynnika siły nośnej, współczynnika momentu pochylającego oraz doskonałości aerodynamicznej przedstawiono w formie tabel i wykresów. Wykonane badania posłużyły przede wszystkim do walidacji wyników numerycznych, które były przeprowadzone w trakcie realizacji projektu „Lotniczo-rakietowy system wynoszenia ładunków na niską orbitę okołoziemską - studium realizowalności”.

4

Experimental Determination of the Effect of Floats on Aerodynamic Characteristics of the “OSA” Aircraft in Asymmetric Flow

Frant Michał, Wrzesień Stanisław, Majcher Maciej

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2022

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Vol. 13, Nr 1 (47)

27--44

EN

This study provides the results of experimental tests of the effect of floats on the aerodynamic characteristics of the “OSA” plane in an asymmetric flow. The tests were carried out in a low-speed wind tunnel owned by Institute of Aviation Technology, Faculty of Mechatronics, Armament and Aerospace (FMAA), Military University of Technology (MUT, Warsaw, Poland). The model of “OSA” was tested at dynamic pressure q = 500 Pa within the range of slip angles β = -28°÷28°. The tests were carried out for the plane model in the so-called “plain” configuration, i.e. at non-deflected control surfaces and wing mechanisation elements. The model was tested in two variants – with floats and without floats. The effect of deflection of the flaps, ailerons and rudder on the aerodynamic characteristics of the test model was also examined. The obtained values of drag coefficient, lateral force coefficient and yawing moment coefficient are presented in the form of tables and graphs. The tests showed that the floats had a significant impact on the curves of the characteristics. They result in a considerable increase of the value of the drag coefficient and in a deterioration of weathercock stability.

5

Pressure distribution on rectangular tall buildings in boundary layer flows

Lipecki Tomasz

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 2

art. no. e83, 1--17

EN

The paper discusses wind tunnel measurements performed on vertically placed rectangular prisms representing medium and high-rise buildings. The results concern mean wind velocity pressure coefficient. The influences of the angle of wind attack, boundary layer and dimensions of models are considered. Two rectangular models of side ratio D/B = 2 (0.5) and two models of side ratio D/B = 4 (0.25) and different aspect ratios are investigated. Four cases of boundary layer flows are simulated. The prisms are examined at a full range of wind angles that change every 15°. Spatial distributions of the mean wind velocity pressure are similar between models and boundary layers at all angles of wind attack but differ significantly in values, especially on windward and side walls. The boundary layer characteristics have slightly stronger influence on the mean pressure coefficient on windward walls than the change in side ratio and dimensions of models. From the other hand, the change in model geometry influences suction a little stronger on leeward and side walls than the change of boundary layer. The wind action on windward wide wall causes greater differences of pressure on this wall and smaller differences of suction on side and leeward walls than the wind action on windward narrow wall. The oblique angles of wind attack cause greater suction at top parts of the models near the roof due to forming conical vortices.

6

Experimental Determination of the Impact of Floats on the Aerodynamic Characteristics of an OSA Model in Symmetric Flow

Frant Michał, Wrzesień Stanisław, Majcher Maciej

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2021

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Vol. 12, Nr 1 (43)

41--58

EN

This paper presents the results of experimental determination of the impact of floats on the aerodynamic characteristics of an OSA model in symmetric flow. The studies have been performed in the low-speed wind tunnel at the Military University of Technology (MUT, Warsaw, Poland). The aircraft model was examined at the dynamic pressure q = 500 Pa in the following angle of attack range α = -28⁰÷28⁰. The investigations have been performed for an aircraft model under plain configuration with floats and without floats. The influence of elevator and flap inclination on the aerodynamic characteristics of the model has also been analysed. The obtained values of aerodynamic drag coefficient, lift coefficient, pitching moment coefficient and lift-to-drag ratio have been presented in the form of tables and graphs. The studies performed demonstrated that the use of floats causes the increase of aerodynamic drag coefficient ϹD, maximum lift coefficient Ϲ Lmax as well as critical angle of attack α cr. The decrease of lift-to-drag ratio has also been observed. Its value in the case of the model with floats was up to 20% lower than in the model without floats. The studies also showed that the model equipped with floats had a lower longitudinal static stability margin than the model without floats.

PL

W pracy przedstawiono wyniki badań doświadczalnych wpływu pływaków na charakterystyki aerodynamiczne modelu samolotu OSA w opływie symetrycznym. Badania wykonano w tunelu aerodynamicznym małych prędkości WAT. Model zbadano przy ciśnieniu dynamicznym q = 500 Pa w zakresie kątów natarcia α = -28⁰÷28⁰. Badania wykonano dla modelu samolotu w konfiguracji "gładkiej" w wersji z pływakami i bez pływaków. Zbadano również wpływ wychylenia usterzenia poziomego oraz klap na podstawowe charakterystyki aerodynamiczne badanego modelu. Uzyskane wartości współczynnika oporu aerodynamicznego, współczynnika siły nośnej, współczynnika momentu pochylającego oraz doskonałości aerodynamicznej przedstawiono w formie tabel i wykresów. Przeprowadzone badania wykazały, że zastosowanie pływaków powoduje wzrost wartości zarówno współczynnika siły oporu aerodynamicznego, maksymalnej wartości współczynnika siły nośnej jak i wartości krytycznego kąta natarcia α kr. Zauważalny jest także spadek wartości doskonałości aerodynamicznej która dla modelu z pływakami jest nawet o 20% mniejsza od doskonałości uzyskanej dla modelu bez pływaków. Badania pokazały również, że model wyposażony w pływaki ma mniejszy zapas stateczności statycznej podłużnej niż model bez pływaków.

7

Wind tunnel tests of hovering propellers in the transition state of Quad-Plane

Pobikrowska Katarzyna, Goetzendorf-Grabowski Tomasz

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 6

art. no. e138821

EN

The following paper presents wind tunnel investigation of aerodynamic characteristics of hovering propellers. This propulsion system may be applied on a lightweight Quad Plane VTOL (Vertical Take-Off and Landing) UAV (Unmanned Aerial Vehicle). A Quad Plane is a configuration consisting of a quadcopter design combined with a conventional twin-boom airplane. This kind of design should therefore incorporate the advantages of both types of vehicles in terms of agility and long endurance. However, those benefits may come with a cost of worse performance and higher energy consumption. The characteristics of a fixed-wing aircraft and propellers in axial inflow are well documented, less attention is put to non-axial flow cases. VTOL propellers of a hybrid UAV are subject to a multitude of conditions – various inflow speeds and angles, changing RPMs, interference between propellers and between nearby aerodynamic structures. The tested system presented in this article consists of four electric motors with two coaxial pairs of propellers mounted on one of the fuselage beams. Such a configuration is often chosen by designers of small and medium hybrid UAVs. There is a need for studies of clean, efficient ways of transporting, and this article can aid future designers of a new type of electric UAVs.

8

Open low speed wind tunnel – design and testing

Szwaba Ryszard, Hinc Krzysztof, Ochrymiuk Tomasz, Krzemianowski Zbigniew, Doerffer Piotr, Kurowski Marcin

Archives of Thermodynamics

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2021

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Vol. 42, no 1

57--70

EN

This paper presents the design method and the construction details of a subsonic low-speed wind tunnel, which has been designed to achieve the flow velocity of 35 m/s in the measurement section with expected uniform velocity field at its inlet. To achieve such objectives a very detailed design was performed using a theoretical 1D analysis and computational fluid dynamics simulations. This approach was applied to improve the flow quality along the wind tunnel sections. When the wind tunnel has been launched a direct comparison of the experimentally measured flow field in the test section and numerical simulation results was conducted. Such comparison of the simulation results with the experimental one is presented in this paper. The obtained results confirm that assumed wind tunnel design method was correct, i.e. the pressure drop in the wind tunnel has been predicted very well and drive system is effective and sufficient to accelerate the airflow to required values.

9

Analysis of aerodynamic phenomena in selected quarter of building development in warsaw downtown with reference to air pollution

Chudzińska Agnieszka, Poćwierz Marta, Pisula Maciej

Architecturae et Artibus

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2021

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Vol. 13, no. 3

1--18

EN

Air pollution, both gaseous and in the form of dust, is a problem that affects numerous densely built-up areas of modern cities. Based on this assumption, the authors of the following paper have examined an exemplary part of urban space with various building developments located in Warsaw downtown. Both experimental and numerical studies were conducted for the two prevailing wind directions observed in this area, that is the west wind and the south-west wind. Experimental research was conducted with the application of two known laboratory techniques, i.e., the oil visualization method and the sand erosion technique. The studies were conducted in an open-circuit wind tunnel. Commercial ANSYS Fluent program was used for numerical simulations. The k-e realizable turbulence model, often applied for this type of tasks, was used in the calculations. As a result, distributions of the velocity amplification coefficient were obtained in the area under consideration, as well as images that present the averaged airflow direction. On basis thereof, potential zones where contamination accumulation may occur were determined. The impact that introduction of a hypothetical high-rise building into the area would exert on wind conditions in its vicinity was also tested. High-rise buildings tend to intensify airflow in their immediate vicinity. Thus, they can improve ventilation conditions of nearby streets. However, in this particular case, the research prompted the conclusion that the proposed building causes turbulence and increased velocity gradients in the majority of elevation planes. On the other hand, in the ground-level zone, the building blocks rather than intensifies the airflow.

10

Use of Wind Tunnel Measurements Data in Cold Launched Missile Flight Simulations

Ożóg Rafał, Jacewicz Mariusz, Głębocki Robert

Pomiary Automatyka Robotyka

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2020

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R. 24, nr 1

49--60

EN

This article presents the results of wind tunnel testing of a model of a missile intended for a vertical cold launch system. The objective of this work was to obtain nondimensional aerodynamic coefficients to build a lookup table database for a six-degree-of-freedom numerical simulation of the missile launch phase. The material model of the full-scale missile was designed in UG/NX Siemens software and manufactured. Low speed measurements were conducted at the Warsaw University of Technology and as a result, static forces and moments characteristics were obtained using six component internal balance for a wide range of angles of attack and sideslip with a 1° interval. Finally, 200 Monte-Carlo simulations in MATLAB/Simulink were evaluated to investigate the missile behavior in the launch phase with the measured results. It was observed that the rolling moment resulting, i.a. from fin cant angles misalignments in the initial roll rate of the missile significantly affects the trajectories.

PL

Niniejszy artykuł przedstawia wyniki testów w tunelu aerodynamicznym modelu rakiety dedykowanej dla pionowego zimnego startu. Celem pracy było uzyskanie bezwymiarowych współczynników aerodynamicznych potrzebnych do opracowania bazy w postaci tablic dla numerycznej symulacji lotu o sześciu stopniach swobody. Model materialny pełnowymiarowej rakiety został zaprojektowany przy wykorzystaniu programu Siemens UG/NX. Testy zostały przeprowadzone na Politechnice Warszawskiej przy niskiej prędkości przepływu a charakterystyki statycznych sił i momentów uzyskano za pomocą sześcioskładnikowej wagi wewnętrznej dla szerokiego zakresu kątów natarcia i ślizgu z krokiem 1°. Ostatecznie, przeprowadzono 200 symulacji Monte-Carlo w programie MATLAB/Simulink w celu zbadania zachowania pocisku w fazie startu z użyciem zmierzonych wartości. Zostało zaobserwowane, że moment przechylający wynikający m.in. z niedokładności montażowych stabilizatorów wpływa znacząco na uzyskiwane trajektorie.

11

Analysis of fan blade vibration with a non-contact method

Porco Pierluigi, Przysowa Radosław, Botto Daniele

Journal of KONBiN

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2020

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Vol. 50, iss. 1

341--357

EN

Composite fan blades are more and more common both in aviation and ground applications. This work aims to characterize the vibration parameters of plastic blades installed in a wind tunnel fan by a non-contact method, namely blade tip timing (BTT). Blade dynamics was predicted with finite element modelling (FEM) and confirmed experimentally by tip timing measurements and analysis of data. BTT results were acquired and compared in two different configurations. A good agreement between predicted and measured frequency values was obtained for the fundamental mode. Significant differences were observed for the second and third modes due to material anisotropy and contact effects which could not be modelled because necessary material data were unavailable.

12

Wind Tunnel Research on the Unmanned Aerial Vehicle Rotor Blade Setting Angle

Siadkowska Ksenia

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 4

104--114

EN

The recommended optimal twist angles were determined for particular sections of the prototype rotor blade dedicated to an unmanned helicopter. The main rotor blade was tested in the GUNT HM 170 tunnel for four different air flow velocities and variable angles of attack. The blade model was divided into sections, each of them was made in the 3D printing technology. For all the sections, the maximum lift and drag forces were determined and then converted to dimensionless values. The aerodynamic characteristics were calculated for each section and different air flow velocities in the wind tunnel. Due to the division of the blade into sections, it was possible to define the most favorable angles of attack along the rotor radius. Aerodynamic excellence was identified for each blade section and air flow velocities.

13

Sprawdzenie stosowalności cyfrowej anemometrii obrazowej do badania opływu ruchomych obiektów w przewodzie zamkniętym

Gawor M., Sobczyk J., Wodziak W., Gnatowska R.

Prace Instytutu Mechaniki Górotworu PAN

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2018

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T. 20, nr 3

231--238

PL

Wykonano badania przepływu powietrza wokół poruszającego się obiektu w tunelu aerodynamicznym. Układ pomiarowy składał się z dwóch prętów o przekroju kwadratowym. Pierwszy z prętów został umieszczony na stałe w pobliżu wlotu do komory pomiarowej, natomiast drugi z prętów oddalał się od lub zbliżał do pierwszego z określoną prędkością. Pomiary przy użyciu cyfrowej anemometrii obrazowej przeprowadzono dla prędkości napływu wynoszącej 1.55 m/s oraz prędkości poruszania się pręta 0.01 m/s. Zarejestrowano zmiany struktury przepływu pomiędzy prętami w zależności od odległości między nimi oraz od zwrotu prędkości pręta. Podjęto próbę obiektywnego wyznaczenia odległości pomiędzy prętami przy której następuje zmiana struktury przepływu.

EN

Investigations of airflow past moveable object were carried out in a wind tunnel. Experimental setup consisted of two squares cylinders in the inline configuration. The first of them was permanently attached close to the measuring chamber inlet. The second cylinder was moving forth and back with velocity Vc = 0,01 m/s. Particle Image Velocimetry measurements were performed for the free stream velocity V∞ = 1,55 m/s. Observed flow patterns were changing depending on the distance between cylinders and direction of motion of the cylinder. An attempt was made to objectively determine the distance between cylinders at which the flow patterns used to change.

14

Turbina wiatrowa VAWT – pomiar sił naporu łopaty w tunelu aerodynamicznym

Fedak W., Gancarski W., Anweiler S., Niesłony A., Ulbrich R.

Napędy i Sterowanie

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2018

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R. 20, nr 5

97--101

PL

Artykuł przedstawia badania łopaty turbiny wiatrowej VAWT typu karuzelowego w tunelu aerodynamicznym. Przedstawia rodzaj i budowę tunelu, sposób pomiaru, a także układ pomiarowy do pomiaru siły naporu hydrodynamicznego. Zamieszczono również wyniki pomiarów sił działających na łopatę turbiny wiatrowej. Kluczowym aspektem jest przełożenie sił współrzędnych układu pomiarowego na siły powodujące obrót turbiny, czyli siły styczne i normalne turbiny.

EN

The article presents research on a wind turbine blade VAWT in a wind tunnel. It presents the type and construction of the tunnel, the measurement method as well as the measuring system for measuring the hydrodynamic thrust force. It also presents the results of measurements of forces acting on the wind turbine blade. The key aspect is the transfer of the coordinate forces of the measurement system to the forces that cause the turbine to turn, that is, tangential and normal forces of the turbine.

15

Turbina wiatrowa VAWT – komputerowe badania symulacyjne

Fedak W., Gancarski W., Anweiler S., Niesłony A., Ulbrich R.

Napędy i Sterowanie

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2018

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R. 20, nr 7/8

124--128

PL

Artykuł przedstawia sposób wyznaczania wartości i przebiegu mocy dla pojedynczej łopaty oraz całej turbiny o pionowej osi obrotu w zależności od ilości użytych łopat. W obliczeniach wykorzystano dane z pomiarów współczynnika oporu od kąta ustawienia profilu łopaty anemometru względem kierunku wiatru oraz pomiary sił działających na łopatę turbiny karuzelowej.

EN

The article presents the method of determining the value and the power course for a single blade and the whole turbines with a VAWT, depending on the number of blades used. The calculations used data from coefficient of resistance measurements from the angle of the anemometer blade profile to the wind direction, and measurements of forces acting on the rotor blade.

16

Experimental study of flow control over an Ahmed body using plasma actuator

Shadmani S., Mousavi Nainiyan S. M, Ghasemiasl R., Mirzaei M., Pouryoussefi S. G.

Mechanics and Mechanical Engineering

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2018

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Vol. 22, nr 1

239--251

EN

Ahmed Body is a standard and simplified shape of a road vehicle that’s rear part has an important role in flow structure and it’s drag force. In this paper flow control around the Ahmed body with the rear slant angle of 25° studied by using the plasma actuator system situated in middle of the rear slant surface. Experiments conducted in a wind tunnel in two free stream velocities of U = 10 m/s and U = 20 m/s using steady and unsteady excitations. Pressure distribution and total drag force was measured and smoke flow visualization carried out in this study. The results showed that at U = 10 m/s using plasma actuator suppress the separated flow over the rear slant slightly and be effective on pressure distribution. Also total drag force reduces in steady and unsteady excitations for 3.65% and 2.44%, respectively. At U = 20 m/s, using plasma actuator had no serious effect on the pressure distribution and total drag force.

17

Experimental study of flow control over a standard road vehicle using plasma actuator

Shadmani S., Mousavi Nainiyan S. M., Ghasemiasl R., Mirzaei M., Pouryoussefi S. G.

Mechanics and Mechanical Engineering

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2018

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Vol. 22, nr 4

1047--1059

EN

Ahmed Body is a standard and simplified shape of a road vehicle that's rear part has an important role in flow structure and it's drag force. In this paper flow control around the Ahmed body with the rear slant angle of 25˚ studied by using the plasma actuator system situated in middle of the rear slant surface. Experiments conducted in a wind tunnel in two free stream velocities of U = 10m/s and U = 20m/s using steady and unsteady excitations. Pressure distribution and total drag force were measured and smoke flow visualization carried out in this study. The results showed that at U = 10m/s using plasma actuator suppress the separated flow over the rear slant slightly and be effective on pressure distribution. Also, total drag force reduces in steady and unsteady excitations for 3.65% and 2.44%, respectively. At U = 20m/s, using plasma actuator had no serious effect on the pressure distribution and total drag force.

18

The initial analysis of the aerodynamic characteristics of a 3D printed model of an aircraft

Lusiak T., Babel R.

Journal of KONES

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2018

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Vol. 25, No. 4

255--262

EN

The aerodynamic research into models of an aircraft aims at creating the main characteristics of aerodynamic forces and moments and the aerodynamic characteristics of coefficients of aerodynamic forces and moments, based on real dimensions. The method of 3D printing was used to create a model of an aircraft. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The printing parameters were corrected in the next printing sessions so the surfaces of the components were good enough and grinding was unnecessary. Some excess material was removed in each of the printed components, and the slots were cleaned. Then, the individual models were put together. The article describes the technique of creating a model of an aircraft to map its exact geometry for experimental wind tunnel research. 3D printing enables us to experimentally investigate a created geometry, in particular to investigate further prior to releasing an aircraft to service. The 3D model employs the model created in line with the previous CFD analysis.

19

Badania modelowe oddziaływania wiatru na membrany i ramy nośne hal namiotowych

Kłaput R., Kocoń A., Flaga A.

Inżynieria i Budownictwo

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2018

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R. 74, nr 10

527--532

PL

Podano wyniki badań rozkładu współczynników ciśnienia wiatru na dachach czterech różnych hal namiotowych. W tunelu aerodynamicznym Politechniki Krakowskiej przebadano cztery tego rodzaju hale różnych kształtów. Na podstawie tych pomiarów określono schematy rozkładu współczynników ciśnienia wiatru. Otrzymane wyniki oddziaływań wiatru na membrany i ramy nośne badanych hal namiotowych oraz ich analizy i porównania mają duże znaczenie z punktu widzenia projektowania tego rodzaju konstrukcji.

EN

This paper concerns measurements of wind pressure distributions on the roofs of four different tent hall models. Four tent halls of different shapes and constructions were investigated in the boundary layer wind tunnel at Cracow University of Technology, Poland. On the basis of these measurements, different schemes of wind pressure coefficient distributions on membranes and bearing frames for these structures were determined. The obtained results, their analyses and comparisons are of great importance from a structural design point of view for such types of structures.

20

Investigation of aerodynamic interference in a multirotor by PIV method

Czyż Zbigniew, Stryczniewicz Wit

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 1

106--114

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.