PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 7

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  vertical cylinder
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote On gravity response over vertical cylinder: some notes
Roy Indrajit Ghosh
Acta Geophysica
|
2023
|
Vol. 71, no. 6
2663--2673
EN
The aspects of gravity modelling with a semi-infinite vertical line of mass as an approximation to the model of semi-infinite vertical cylinder is critically reviewed. The brief outline of the derivations of gravity response due to both type of models, such as the semi-infinite vertical line of mass and vertical right circular cylinder, is given. The model of semi-infinite vertical right circular cylinder provides no closed form formula to compute gravity response on a free horizontal surface, and the ensuing formulation is comprised of elliptic integrals of the first and second kinds. On the other hand, there exists closed form formula of computing gravity response due to semi-infinite vertical line of mass that approximates closely to the semi-infinite vertical thin rod. Assessment on the limitation of replacing vertical cylinder model by vertical line of mass both by rigorous theoretical discourse and numerical tests is made. It is shown via numerical experiment that if the radius of cross section of the vertical right circular cylinder is one-tenth of its depth of burial, then the approximation of line of mass model would provide reasonably accurate results in the order of 10-4.
2
Content available remote Stagnation point flow of Eyring Powell fluid in a vertical cylinder with heat transfer
Rehman A., Achakzai S., Nadeem S., Iqbal S.
Journal of Power Technologies
|
2016
|
Vol. 96, nr 1
57--62
EN
In this paper an analysis is carried out to examine the effects of natural convection heat transfer for steady boundary layer flow of an Eyring Powell fluid flowing through a vertical circular cylinder. The governing partial differential equations along with the boundary conditions are reduced to dimensionless form by using the boundary layer approximation and applying suitable similarity transformations. The resulting nonlinear coupled system of ordinary differential equations subject to the appropriate boundary conditions is solved using the analytic technique homotopy analysis method (HAM). The effects of the physical parameters on the flow and heat transfer characteristics are presented. The behavior of skinfriction coefficient and Nusselt numbers are also studied for different parameters.
3
Content available remote Modeling the natural convection heating of liquid in a vertical cylinder
Nowak K., Markowski M., Sztorc E.
Technical Sciences / University of Warmia and Mazury in Olsztyn
|
2010
|
nr 13
10-21
EN
Natural convection heating within a can of liquid food was simulated by solving the governing equations for continuity, momentum and energy conservation in an axisymmetric case using a commercial COMSOL Multiphysics software (Comsol). A physical experiment and computer simulations using four different models were studied. The results allowed to suggest a method of defining the properties of the material and the boundary conditions applied and to determine the usefulness of COMSOL Multiphysics package in modeling the natural convection heating of liquid food.
PL
W pracy przeprowadzono ocenę możliwości wykorzystania pakietu Comsol Multiphysics do modelowania konwekcyjnego ogrzewania cieczy w pionowym zbiorniku w kształcie cylindra. Opisano eksperyment fizyczny oraz symulacje komputerowe procesu oparte na czterech odmiennie zdefiniowanych modelach, zrealizowanych za pomocą pakietu Comsol. Otrzymane wyniki pozwoliły na określenie przydatności pakietu Comsol Multiphysics do modelowania zjawisk konwekcji naturalnej oraz definiowania właściwości modelowanej substancji oraz zastosowanych warunków brzegowych.
4
Content available Badanie konwekcji swobodnej z powierzchni pionowego walca w środowisku hiperbarycznym
Majchrzycka A.
Polish Hyperbaric Research
|
2010
|
nr 1(30)
13-24
PL
W pracy przedstawiono badania, dotyczące konwekcji swobodnej z powierzchni pionowego walca odwzorowującego sylwetkę nurka o zmiennym wydatku energetycznym. Badania wykonano w helu o ciśnieniu p = 0,5-5MPa, a wyniki przedstawiono postaci równania kryterialnego Nu = f(Ra) oraz korelacji, która umożliwia obliczenie współczynnika przejmowania ciepła w funkcji ciśnienia gazu i symulowanego wydatku energetycznego nurka.
EN
The paper reports experimental investigation of natural convection from vertical cylinder that simulates the diver’s body of the different activity level. Experiments were carried out in the hyperbaric helium at absolute pressure range of p=0,5-5 MPa. The results are given as the correlation Nu = f(Ra) and correlation between convective heat transfer coefficient from the outer surface of vertical cylinder, pressure and simulated activity level.
5
Content available remote Thermophoresis free convection from a vertical cylinder embedded in a porous medium
Chamkha A. J., Jaradat M., Pop I.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no 3
471-481
EN
This paper deals with the steady free convection over an isothermal vertical circular cylinder embedded in a fluid-saturated porous medium in the presence of the thermophoresis particle deposition effect. The governing partial differential equations are transformed into a set of non-similar equations, which are solved numerically using an implicit finite-difference method. Comparisons with the previously published work are performed and the results are found to be in excellent agreement. Many results are obtained and a representative set of these results is displayed graphically to illustrate the influence of the various physical parameters on the wall thermophoretic deposition velocity and concentration profiles.
6
Content available remote Free convection from a vertical cylinder embedded in a porous medium filled with cold water
Chamkha A. J., Bercea C., Pop I.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no 2
273-283
EN
A free convection boundary layer flow along a heated vertical cylinder embedded in a porous medium saturated with pure or saline water at low temperatures, up to 20oC, is considered. The boundary layer analysis is formulated in terms of Darcy's law and a new density equation of state, which is of very high accuracy and of simple form, is postulated. Numerical solutions are presented and the flow field characteristics are analysed in detail for both cases of downward and upward flows. A very good agreement between the present results and those reported for particular situations was found.
7
Free and forced convection from a vertical cylinder with constant surface heat flux. - Part I: An asymptotic solution
Scurtu N., Pop I., Postelnicu A.
Applied Mechanics and Engineering
|
2000
|
Vol. 5, no 2
451-469
EN
A theoretical study is conducted in this paper for the development of the steady three-dimensional boundary layer, which is induced by a horizontal forced convection flow past an infinitely long vertical cylinder. It is assumed that the cylinder is partially prescribed with a constant heat flux qw, while the other part of the cylinder is held at the ambient temperature T_. It is also assumed that the secondary flow is induced in the boundary layer by the buoyancy forces. A series solution method is used to solve the governing non-linear set of partial differential equations near the thermal leading edge. It is shown that the effect of the horizontal free stream on the boundary layer gradually increases as one moves upward away from the thermal leading edge along the cylinder. The solution has been obtained for different values of the Prandtl number, Pr, and it is shown that for Pr = 0.733 and Pr = 6.7 the present results are in excellent agreement with those known from the literature.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.