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Wyświetlanie 1-8 z 8
Tytuł:
Analysis of heat transfer in a supersonic rocket head
Analiza wymiany ciepła w głowicy rakiety naddźwiękowej
Autorzy:
Rosłowicz, A.
Bednarczyk, P.
Powiązania:
https://bibliotekanauki.pl/articles/213478.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
rocket technology
computational fluid mechanics
unsteady heat transfer
ANSYS software
technika rakietowa
numeryczna mechanika płynów
nieustalona wymiana ciepła
oprogramowanie ANSYS
Opis:
Design of supersonic HI rocket by the Rocketry Group of Students' Space Association (SR SKA) requires an analysis of thermal phenomena occurring in the elements particularly exposed to the high temperature gas. This paper contains a description of the methodology and the results of numerical simulation of heat transfer in the elements of the rocket head. The starting points were the flight conditions (3 characteristic points defined by altitude and Mach number) and independently calculated adiabatic temperature field of the gas. ANSYS Fluent code was used to determine the temperature field on the surface of the rocket. Computed cases were viscous and inviscid flow (for comparison). Based on the results formulated for the viscous case heat transfer boundary conditions, the numerical model and the thermophysical properties of materials were defined. The model was limited to a brass top part of the head and a part of a composite dome. Analytical and empirical method of "intermediate enthalpy" determined distribution of the heat transfer coefficient on the rocket surface. Then the transient heat transfer was calculated with the ANSYS system. It included the range from the rocket launch, moment of maximum Mach number to sufficient structure cooling. The results of the analyses were conclusions relevant to the further development work. Excessive heating of composite structures during the flight has been shown.
Niniejszy artykuł zawiera opis metody oraz wyniki numerycznej symulacji wymiany ciepła w elementach głowicy rakiety. Punkt wyjścia stanowiły założone warunki lotu (3 punkty charakterystyczne określone przez wysokość i liczbę Macha) i wyznaczone niezależnie adiabatyczne pole temperatury gazu. Do wyznaczenia pola temperatur na powierzchni rakiety użyty został system ANSYS Fluent. Zostały' obliczone przypadki przepływał lepkiego i nielepkiego (dla porównania). Na podstawie wyników* dla przypadku lepkiego sformułowano warunki brzegowe wymiany ciepła, założenia modelu numerycznego. Model ograniczono do mosiężnej części noskowej i fragmentu kompozytowej kopułki. Metodą analityczno-empiryczną „średniej entalpii" (intermediate enthalpy) wyznaczono rozkład współczynnika przejmowania ciepła na powierzchni rakiety. Następnie dokonano obliczenia nieustalonej wymiany ciepła z wykorzystaniem systemu ANSYS. Obejmowały one zakres od startu rakiety, poprzez moment osiągnięcia maksymalnej liczby Macha, do wystarczającego schłodzenia konstrukcji. Efektem pracy było sformułowanie wniosków istotnych z punktu widzenia dalszych prac konstrukcyjnych, wykazano nadmierne ogrzewanie elementów kompozytowych w trakcie lotu.
Źródło:
Prace Instytutu Lotnictwa; 2017, 1 (246); 79-94
0509-6669
2300-5408
Pojawia się w:
Prace Instytutu Lotnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MHD two-layered unsteady fluid flow and heat transfer through a horizontal channel between
Autorzy:
Linga Raju, T.
Nagavalli, M.
Powiązania:
https://bibliotekanauki.pl/articles/955179.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
magnetohydrodynamika
przepływ niestacjonarny
transfer ciepła
magnetohydrodynamics
immiscible fluids
rotating fluid
unsteady flow
heat transfer
Opis:
An unsteady magnetohydrodynamic (MHD) two-layered fluids flow and heat transfer in a horizontal channel between two parallel plates in the presence of an applied magnetic and electric field is investigated, when the whole system is rotated about an axis perpendicular to the flow. The flow is driven by a constant uniform pressure gradient in the channel bounded by two parallel insulating plates, when both fluids are considered as electrically conducting, incompressible with variable properties, viz. different viscosities, thermal and electrical conductivities. The transport properties of the two fluids are taken to be constant and the bounding plates are maintained at constant and equal temperatures. The governing partial differential equations are then reduced to the ordinary linear differential equations using two-term series. Closed form solutions for primary and secondary velocity, also temperature distributions are obtained in both the fluid regions of the channel. Profiles of these solutions are plotted to discuss the effects of the flow and heat transfer characteristics, and their dependence on the governing parameters involved, such as the Hartmann number, rotation parameter, ratios of the viscosities, heights, electrical and thermal conductivities.
Źródło:
International Journal of Applied Mechanics and Engineering; 2014, 19, 1; 97-121
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Open-Source CFD analysis of multi-domain unsteady heating with natural convection
Autorzy:
Sosnowski, P.
Pozorski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1943189.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska
Tematy:
CFD
open source software
unsteady heating
natural convection
multi-domain heat transfer
Opis:
The paper presents the capabilities of open-source programs used for numerical simulation of fluid flow and heat transfer phenomena. These tools are applied for unsteady problems with natural convection and, in particular, the heating of an automotive headlight. To perform these studies, a solver was created using an open-source C++ library OpenFOAM. The implementation problems encountered were, inter alia, dealing with multi-domain computation and coupling of sub-domains. The presented simulation results clearly show that open-source software can readily be applied also to engineering problems and can compete with commercial packages.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2009, 13, 4; 403-414
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MHD heat transfer in two-layered flow of conducting fluids through a channel bounded by two parallel porous plates in a rotating system
Autorzy:
Linga Raju, T.
Neela Rao, B.
Powiązania:
https://bibliotekanauki.pl/articles/264768.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
magnetohydrodynamika
przenikanie ciepła
porowatość
MHD
two-layered fluids/immiscible fluids
unsteady flow
heat transfer
rigid rotation
porous boundaries
Opis:
The paper aims to analyze the heat transfer aspects of a two-layered fluid flow in a horizontal channel under the action of an applied magnetic and electric fields, when the whole system is rotated about an axis perpendicular to the flow. The flow is driven by a common constant pressure gradient in the channel bounded by two parallel porous insulating plates, one being stationary and the other one oscillatory. The fluids in the two regions are considered electrically conducting, and are assumed to be incompressible with variable properties, namely, different densities, viscosities, thermal and electrical conductivities. The transport properties of the two fluids are taken to be constant and the bounding plates are maintained at constant and equal temperature. The governing partial differential equations are then reduced to the ordinary linear differential equations by using a two-term series. The temperature distributions in both fluid regions of the channel are derived analytically. The results are presented graphically to discuss the effect on the heat transfer characteristics and their dependence on the governing parameters, i.e., the Hartmann number, Taylor number, porous parameter, and ratios of the viscosities, heights, electrical and thermal conductivities. It is observed that, as the Coriolis forces become stronger, i.e., as the Taylor number increases, the temperature decreases in the two fluid regions. It is also seen that an increase in porous parameter diminishes the temperature distribution in both the regions.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 3; 623-648
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Hall effect on MHD 2-fluid unsteady heat transfer flow of plasma in a rotating system via a straight channel between conducting plates
Autorzy:
Raju, T. Linga
Rao, B. Venkata
Powiązania:
https://bibliotekanauki.pl/articles/2174207.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
wymiana ciepła
efekt Halla
plazma
unsteady flow
MHD
immiscible flow
heat transfer
Hall effect
plasma
rotating frame
conducting plate
Opis:
Hall currents are used to investigate MHD unsteady two fluid flows and heat transport of plasma along a straight channel of conducting plates. In the two liquid zones, the velocity and temperature fields for the case of conducting side plates are obtained by solving the governing equations using a two-term series under the specified conditions. The distribution profiles are graphically resolved and examined. The distributions are thought to be dependent on the electron-to-total pressure ratio. The flow and heat transfer factors are also influenced by other parameters such as the Hartmann number, Hall parameter, rotation parameter, thermal conductivity and viscosity ratio.
Źródło:
International Journal of Applied Mechanics and Engineering; 2022, 27, 3; 137--162
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Convective heat transfer in a micropolar fluid over an unsteady stretching surface
Autorzy:
Prasad, K. V.
Vaidya, H.
Vajravelu, K.
Powiązania:
https://bibliotekanauki.pl/articles/266164.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przepływ niestacjonarny
wymiana ciepła
tarcie
metoda Keller-box
unsteady flow
microrotation
heat transfer
skin friction
Nusselt number
Keller-box method
Opis:
An unsteady boundary layer free convective flow and heat transfer of a viscous incompressible, microploar fluid over a vertical stretching sheet is investigated. The stretching velocity is assumed to vary linearly with the distance along the sheet. Two equal and opposite forces are impulsively applied along the x-axis so that the sheet is stretched, keeping the origin fixed in the micropolar fluid. The transformed highly non-linear boundary layer equations are solved numerically by an implicit finite difference scheme for the transient, state from the initial to the final steady-state. To validate the numerical method, comparisons are made with the available results in the literature for some special cases and the results are found to be in good agreement. The obtained numerical results are analyzed graphically for the velocity, the microrotation, and the temperature distribution; whereas the skin friction, the couple stress coefficient and the Nusselt number are tabulated for different values of the pertinent parameters. Results exhibit a drag reduction and an increase in the surface heat transfer rate in the micropolar fluid flow compared to the Newtonian fluid flow.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 2; 407-422
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady electro-magneto hydrodynamic flow and heat transfer of two ionized fluids in a rotating system with Hall currents
Autorzy:
Raju, T. Linga
Rao, B. Venkat
Powiązania:
https://bibliotekanauki.pl/articles/2174167.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
transfer ciepła
przepływ nieustalony
plazma
pole magnetyczne
pole elektryczne
unsteady flow
magnetic field
electric field
immiscible flow
plasma
Hall effect
rotating frame
heat transfer
insulating plate
Opis:
An unsteady flow and heat transmission of ionized gases via a horizontal channel enclosed by non-conducting plates in a rotating framework with Hall currents is examined using electro-magnetohydrodynamic (EMHD) two-fluid heat flow. The Hall current impact is taken into account by assuming that the gases are totally ionized, the applied transverse magnetic field is very strong. For temperature and velocity distributions in two-fluid flow regions, the governing equations are solved analytically. For numerous physical parameters such as the Hartmann number, Hall parameter, rotation parameter, viscosity ratio, and so on, numerical solutions are visually displayed. It was discovered that an increase in temperature in the two regions is caused by the thermal conductivity ratio. It was also realized that an increase in rate of heat transfer coefficient at the plates is caused by either the Hartman number or the Hall parameter.
Źródło:
International Journal of Applied Mechanics and Engineering; 2022, 27, 1; 125--145
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady two-layered fluid flow and heat transfer of conducting fluids in a channel between parallel porous plates under transverse magnetic field
Autorzy:
Linga Raju, T.
Nagavalli, M.
Powiązania:
https://bibliotekanauki.pl/articles/264466.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
magnetohydrodynamika
mieszanie płynów
przepływ niestacjonarny
ruch oscylacyjny
przenikanie ciepła
magnetohydrodynamics
two-layered fluid flow/immiscible fluids
unsteady flow
oscillatory motion
heat transfer
porous plate
Opis:
The unsteady magnetohydrodynamic flow of two immiscible fluids in a horizontal channel bounded by two parallel porous isothermal plates in the presence of an applied magnetic and electric field is investigated. The flow is driven by a constant uniform pressure gradient in the channel bounded by two parallel insulating plates, one being stationary and the other oscillating, when both fluids are considered as electrically conducting. Also, both fluids are assumed to be incompressible with variable properties, viz. different viscosities, thermal and electrical conductivities. The transport properties of the two fluids are taken to be constant and the bounding plates are maintained at constant and equal temperatures. The governing equations are partial in nature, which are then reduced to the ordinary linear differential equations using two-term series. Closed form solutions for velocity and temperature distributions are obtained in both fluid regions of the channel. Profiles of these solutions are plotted to discuss the effect on the flow and heat transfer characteristics, and their dependence on the governing parameters involved, such as the Hartmann number, porous parameter, ratios of the viscosities, heights, electrical and thermal conductivities.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 699-726
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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