Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "drag coefficient" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 22
Tytuł:
Laboratory tests of the aerodynamic drag coefficient of the flag as a body with low stiffness
Autorzy:
Wilk, A.
Skuta, M.
Powiązania:
https://bibliotekanauki.pl/articles/1943232.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska
Tematy:
aerodynamic drag coefficient
flag
Opis:
The shape and drag of bodies with small stiffness may change during the airflow. This problem refers to such bodies as flags, bands, banners, flapping sails as well as blades and cables which vibrate due to the flow. Laboratory tests carried out to point out the aerodynamic drag coefficient of a flag are discussed in this article. The laboratory tests were carried out in an aerodynamic tunnel at different airflow velocities for flags with different dimensions made of fabrics of different roughness and stiffness. The drag coefficient value decreases with the increasing airflow velocity. The drag coefficient is higher for materials with higher roughness. The drag coefficient value is also influenced by the fabric stiffness and kind of edge. Great engineering importance to the stability of a structure (e.g. a flag mast) and the safety of nearby persons and buildings are attached to the analyzed problem.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2009, 13, 1-2; 5-14
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of GPS receiver to road tests of automobile
Autorzy:
Sar, H.
Pokorski, J.
Fundowicz, P.
Reński, A.
Powiązania:
https://bibliotekanauki.pl/articles/242475.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
automobile dynamics
air drag coefficient
rolling drag coefficient
ECE 13 Regulation
road transport
Opis:
The article presents the assessment of the possibilities of applying GPS receiver for the measurement and acquisition of the longitudinal velocity of automobile in the investigations of longitudinal dynamics of automobile. For many years for the measurement of the longitudinal velocity Correvit-L sensors are applied. Major simplification of the measurement of the velocity with the GPS receiver, compared with correlational-optical sensors Correvit-L is giving the possibility to faster prepare the automobile for examinations. The more so as only recently GPS receivers with 10 Hz sampling rate are available. In the paper is shortly described the software specially designed for the measurements that makes it possible to simultaneously measure both the longitudinal velocity signal from GPS receiver and from Correvit-L sensor in real time. Furthermore, the application of the measurement of the velocity is presented on the basis of such road tests as the attempt of accelerating through the following gears, the attempt of free deceleration and the attempt of braking according to ECE 13 Regulation. On the basis of the mentioned manoeuvers the characteristics of the vehicle’s acceleration and dynamic coefficient, rolling and air drag coefficient and the braking deceleration were determined. The paper shows also some problems connected with applying GPS receiver to measure longitudinal velocity of the automobile.
Źródło:
Journal of KONES; 2013, 20, 3; 359-366
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Aerodynamic Characteristics of the Rocket-Target for the „Stinger” System
Autorzy:
Fedaravičius, A.
Kilikevičius, S.
Survila, A.
Patašienė, L.
Powiązania:
https://bibliotekanauki.pl/articles/403737.pdf
Data publikacji:
2016
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
aerodynamics
drag force
drag coefficient
rocket-target
Opis:
This paper presents an analysis of aerodynamic characteristics of the rocket target for the final training of shooting at aerial targets by the „Stinger” system service staff. The governing equations of fluid dynamics are presented and the computational model of airflow around the rocket is developed. ANSYS CFX computational fluid dynamics software is used to compute airflow velocities, pressure, the drag force and the drag coefficient. A practical implementation of the research is presented. Taking into account the simulation results, the rocket-target was designed and manufactured.
Źródło:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa; 2016, 7, 1 (23); 7-16
2081-5891
Pojawia się w:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on Ahmed’s body drag coefficient
Autorzy:
Wysocki, Dominik
Szymanek, Arkadiusz
Powiązania:
https://bibliotekanauki.pl/articles/2133935.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
Ahmed body
aerodynamics
wind tunnel
drag coefficient
boundary layer
Opis:
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.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2022, 25(1); 87--105
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pomiar współczynnika oporu i czynnika kształtu cząstek typu flok
Measurement of drag coefficient and sphericity of floc particles
Autorzy:
Adamski, R.
Pakowski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2071258.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
cząstka typu flok
współczynnik kształtu
floc particles
drag coefficient
Opis:
W literaturze brak informacji nt. współczynnika oporu cząstek typu flok. W tej pracy zmierzono współczynnik oporu metodą stanu nieustalonego i metodą stanu ustalonego oraz porównano wyniki obu metod. Na podstawie współczynnika oporu zidentyfikowano sferyczność w oparciu o równanie Haidera, Levenspiela. Stwierdzono, że zastosowanie teorii przepuszczalności Brinkmana daje lepszy opis współczynnika oporu dla cząstek typu flok.
Drag coefficient of floe type particles is poorly described in literature. In this work drag coefficient was measured by two methods - unsteady state and steady state and the results were compared. On basis of drag coefficient the particle sphericity was identified using the Haider and Levenspiel formula. It was found that a better description of drag coefficient for floe particles was obtained using Brinkman's theory of permeability.
Źródło:
Inżynieria i Aparatura Chemiczna; 2010, 3; 15-16
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D simulation of incompressible flow around a rotating turbulator: Effect of rotational and direction speed
Autorzy:
Zoubai, Elhadi
Laidoudi, Houssem
Tlanbout, Ismail
Makinde, Oluwole Daniel
Powiązania:
https://bibliotekanauki.pl/articles/27312235.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
rotating
turbulator
straight tube
drag coefficient
power number
laminar
flow
Opis:
This paper presents new results for the dynamic behaviour of fluid around a rotating turbulator in a channel. The turbulator has a propeller form which is placed inside a flat channel. The research was carried out using 3D numerical simulation. The rationale of the experiment was as follows: we put a propeller-turbulator inside a flat channel, and then we insert a water flow inside the channel. The turbulator rotates at a constant and uniform speed. The main points studied here are the effect of the presence of turbulator and its rotational direction on the flow behaviour behind the turbulator. The results showed that the behaviour of flow behind the turbulator is mainly related to the direction of turbulator rotating. Also, the studied parameters affect coefficients of drag force and power number. For example, when the turbulator rotates in the positive direction, the drag coefficient decreases in terms of rotational speed of the turbulator, while the drag coefficient increases in terms of rotational speed when the turbulator rotates in the negative direction.
Źródło:
Archives of Thermodynamics; 2023, 44, 2; 139--157
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza porównawcza współczynników oporu naddźwiękowych pocisków moździerzowych
Comparison analysis of drag coefficients for supersonic mortar projectiles
Autorzy:
Magier, M.
Merda, T.
Powiązania:
https://bibliotekanauki.pl/articles/235903.pdf
Data publikacji:
2016
Wydawca:
Wojskowy Instytut Techniczny Uzbrojenia
Tematy:
mechanika
balistyka
pocisk moździerzowy
współczynnik oporu
mechanics
ballistics
mortar projectile
drag coefficient
Opis:
W artykule przedstawiono wyniki analizy porównawczej współczynników oporu uzyskanych na postawie wyników badań strzelaniem i symulacji numerycznych. Wyniki obliczeń numerycznych przeprowadzone metodą CFD z wykorzystaniem oprogramowania Ansys Fluent v16, posłużyły m.in. do opracowania wstępnych tabel strzelniczych dla nowoprojektowanych pocisków do moździerza RAK.
Results of comparison between drag coefficients established by the firing tests and numerical simulations are presented in the paper. The results of numerical calculations carried out by CFD method, exploiting Ansys Fluent v16 software, were used to develop initial firing tables for newly designed projectiles for RAK mortar.
Źródło:
Problemy Techniki Uzbrojenia; 2016, 45, 140; 21-28
1230-3801
Pojawia się w:
Problemy Techniki Uzbrojenia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of the drag coefficient of a motorcycle helmet
Autorzy:
Czyż, Z.
Karpiński, P.
Sevdim, T.
Powiązania:
https://bibliotekanauki.pl/articles/118113.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
numerical analysis
CFD
drag coefficient
motorcycle helmets
analiza numeryczna
współczynnik oporu
kaski motocyklowe
Opis:
The paper discusses a numerical investigation, using a CFD tool, ANSYS FLUENT, of drag acting on a motorcycle helmet. The simulations were performed on a model of a helmet downloaded from a free CAD model library. A solid model enabled us to generate a mesh, to define boundary conditions and to specify a model of turbulence. Accordingly, the values of forces acting on individual sections of the helmet were obtained and the coefficients of aerodynamic drag were calculated. The test results can be used to optimize the shape of the existing motorcycle helmet construction and to study the impact of generated drag forces on reaction forces affecting a motorcyclist’s body.
Źródło:
Applied Computer Science; 2018, 14, 1; 16-26
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and performance of the converging-diverging vortex flowmeter
Autorzy:
Sun, Z.
Powiązania:
https://bibliotekanauki.pl/articles/221011.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
vortex flowmeter
converging-diverging structure
lower limit of measurement
Strouhal number
drag coefficient
Opis:
The converging-diverging structure is introduced to extend the lower limit of measurement of vortex flowmeters. As a compact device, the converging-diverging vortex flowmeter is proposed and designed, and its performance is studied experimentally. It is found that, first of all, an up to 51% extension of the lower measurement limit can be realized through the converging-diverging structure, compared with conventional vortex flowmeters; second, the converging-diverging vortex flowmeter with a trapezoidal bluff body has a larger Strouhal number and smaller pressure loss. The results suggest that the converging-diverging vortex flowmeter provides an alternative device especially suitable for the measurement of low-velocity fluids.
Źródło:
Metrology and Measurement Systems; 2011, 18, 1; 129-136
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An experimental and numerical study of supercavitating flows around axisymmetric cavitators
Autorzy:
Javadpour, S. M.
Farahat, S.
Ajam, H.
Salari, M.
Nezhad, A. H.
Powiązania:
https://bibliotekanauki.pl/articles/949307.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
natural cavitation
mass transfer
water tunnel
finite element method
drag coefficient
axisymmetric cavitators
Opis:
It has been shown that developing a supercavitating flow around under-water projectiles has a significant effect on their drag reduction. As such, it has been a subject of growing attention in the recent decades. In this paper, a numerical and experimental study of supercavitating flows around axisymmetric cavitators is presented. The experiments are conducted in a semi-open loop water tunnel. According to the Reynolds-Averaged Navier-Stokes equations and mass transfer model, a three-component cavitation model is proposed to simulate the cavitating flow. The corresponding governing equations are solved using the finite element method and the mixture Rayleigh-Plesset model. The main objective of this research is to study the effects of some important parameters of these flows such as the cavitation number, Reynolds number and conic angle of the cavitators on the drag coefficient as well as the dimensions of cavities developed around the submerged bodies. A comparison of the numerical and experimental results shows that the numerical method is able to predict accurately the shape parameters of the natural cavitation phenomena such as cavity length, cavity diameter and cavity shape. The results also indicate that the cavitation number declines from 0.32 to 0.25 leading to a 28 percent decrease in the drag coefficient for a 30° cone cavitator. By increasing the Reynolds number, the cavity length is extended up to 322% for a 60° cone cavitator.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 3; 795-810
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ruch pęcherzyka w cieczach i fizykochemiczna metoda detekcji zanieczyszczeń powierzchniowo-aktywnych w wodzie
Bubble motion in liquids and physocochemcal method of detection of surface-active pollutants in water
Autorzy:
Zawała, Jan
Kosior, Dominik
Małysa, kazimierz
Powiązania:
https://bibliotekanauki.pl/articles/1853755.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
surfaktanty
micelizacja
krytyczne stężenie micelarne
ultrafiltracja micelarna
bubble
velocity
surfactant
drag coefficient
dynamic adsorption layer
Opis:
Motion of gas bubbles in aqueous phase (either clean water or solutions of surface-active substances) is a phenomenon of great practical importance. Gas/liquid contacting is one of the most common operations in the chemical and petrochemical industry and mineral processing In particular in mineral industry, for all kind of flotation processes it is the main act responsible for the success of the entire technology As a result, properties of the liquid/gas interfaces are considered as a one of the most important parameters, determining the outcome of industrial applications and engineering processes. These properties can be modified by surfactants which adsorption (molecules accumulation) at the interfaces leads to the decrease in the interfacial tension and modification of the hydrodynamic boundary conditions. Description of a single bubble motion in wide range of flow magnitude (Reynolds numbers) is not trivial and many attempts have been undertaken to quantify a bubble behavior in liquids. This paper presents a short overview of the current “state of arts” on physics of the bubble motion in liquids and the elaborated models, describing motion of the bubble formed in liquid phase. The comparison of the theoretical models predictions with the available experimental data is presented. It is shown, moreover, that the bubble velocity can be used as a very sensitive tool for detection of organic contaminations in environmental water samples.
Źródło:
Wiadomości Chemiczne; 2021, 75, 9-10; 1317-1342
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Environmental Monitoring and Simulation of Infrasound Generating Mechanism of Traffic Flow
Autorzy:
Grafkina, Marina Vladimirovna
Nyunin, Boris Nikolaevich
Sviridova, Evgeniya Yurevna
Powiązania:
https://bibliotekanauki.pl/articles/124397.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
infrasound
ground vehicles
environmental monitoring
infrasound pressure
shedding
vortices
drag coefficient
wheel harmonics
driving speed
Opis:
Ground vehicles are the main sources of noise and infrasounds in residential areas. Numerous published works are devoted to the studies of audible sound, its sources in vehicle, and development of measures to its reduction. The authors believe that the problem of infrasound occurrence and propagation in residential areas and – hence – its negative impact on humans and ambient environment is underestimated. Development of predictions and experimental methods of studying the infrasound generating mechanism and environmental monitoring of this negative factor are an urgent issue. A significant portion of acoustic emission from a vehicle comprises infrasound and low frequency range. Internal and external infrasound of vehicle were measured. A prediction model was proposed and the influence of vehicle design features on the infrasound level was estimated. Predictions of the external infrasound generating the mechanism of vehicles reveal that its frequency and level depend on driving speed, drag coefficient, vehicle body length, and Strouhal number Wheels, which execute rotation and progressive movement in airstream, are important sources of vehicle infrasound. Five wheel harmonics were calculated for motor vehicles at various driving speeds, the existing dependences are detected. It was demonstrated that the regulatory levels of infrasound can be exceeded only in residential areas adjacent to traffic flow with driving speeds higher than 80 km/h. The results of field studies of infrasound level on the streets of Moscow were presented. Recommendations on the development of environmental monitoring and main approaches to reduce infrasound in urban environment were given.
Źródło:
Journal of Ecological Engineering; 2019, 20, 7; 90-97
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
35 mm ammunition’s trajectory model identification based on firing tables
Autorzy:
Baranowski, L.
Gadomski, B.
Majewski, P.
Szymonik, J.
Powiązania:
https://bibliotekanauki.pl/articles/200598.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
identification
exterior ballistics
equations of projectile motion
curve fitting
drag coefficient
identyfikacja
ruch pocisku
współczynnik oporu
Opis:
The article presents a procedure designed for identification of projectile’s trajectory model through aerodynamic coefficients estimation. The identification process is based on firing tables artificially prepared (firing tables prepared using mathematical flight model for the projectile instead of trajectories recorded on field tests) with the use of modified point–mass and rigid body trajectory models. All the necessary data, including physical parameters of the projectile and its aerodynamic characteristics are provided. The detailed results of estimation of chosen aerodynamic coefficients are presented in both visual and tabular form. The main purpose of this paper is to establish the minimum number of trajectories (as characterized in firing tables), and the permissible error of initial parameters being passed to the mathematical model that would allow the correct identification of projectile’s trajectory model.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 5; 635-643
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of computational domain discretization on CFD results concerning aerodynamics of a vehicle
Autorzy:
Sosnowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/122297.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
computational domain discretization
fluid dynamics
aerodynamics
AHMED body
drag coefficient
dyskretyzacja domeny obliczeniowej
dynamika płynów
aerodynamika
współczynnik oporu
Opis:
The paper presents research concerning the influence of computational domain discretization on the results of CFD analysis. Tetrahedral and polyhedral numerical mesh types are analyzed and the mesh convergence index is calculated. The obtained results are compared to the experimental measurements concerning the estimation of drag coefficient of the vehicle model. The research carried out indicates the great influence of pre-processing on the reliability of the obtained results. Moreover, the advantages of polyhedral mesh over tetrahedral mesh are pointed out in the paper.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2018, 17, 1; 79-88
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Granice oporów ruchu w pojazdach : opór aerodynamiczny
Limitations of vehicle movement resistances : aerodynamic resistance
Autorzy:
Wrzecioniarz, A.
Ambroszko, W.
Pindel, A.
Powiązania:
https://bibliotekanauki.pl/articles/317290.pdf
Data publikacji:
2018
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
opór aerodynamiczny
współczynnik oporu aerodynamicznego
samochody osobowe
samochody ciężarowe
pociągi
Hyperloop
aerodynamic resistance
aerodynamic drag coefficient
cars
trucks
trains
Opis:
W artykule omówione zostały granice oraz przykładowe metody minimalizacji oporu aerodynamicznego.
In the paper limitations and exemplary methods of aerodynamic drag force minimization in different kinds of vehicles are described. Changes of value of aerodynamic drag coefficient during years are presented. Conclusions about future possible new solutions in different kinds of vehicles are formulated.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2018, 19, 12; 252-255
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 22

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies