Effect of vortex flows at surface with hollow-type relief on heat transfer coefficients and equilibrium temperature in supersonic flow

Leontiev, A. I.; Vinogradov, Yu. A.; Bednov, S. M.; Golikov, A. N.; Yermolaev, I.K; Dilevskaya, E.V.; Стронгин, М. М.

doi:10.1016/s0894-1777(02)00157-7

Cited by 18 publications

(10 citation statements)

References 1 publication

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“…From the analysis of the temperature distribution on the surface with cavities it was found out (similar to the studies [10,32]) that the largest temperature drop on the surface occurs immediately after the cavity at a distance approximately equal to half the diameter of the cavity. In the centre of the cavity the temperature is practically equal to that of a smooth surface.…”

Section: Expe Ri Mental R Esultssupporting

confidence: 70%

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Experimental study of parameters of surfaces coated with regular relief

Burtsev¹,

Vasil'ev²,

Vinogradov³

et al. 2013

S&E BMSTU

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In trod uctionRecently, in connection with constantly growing prices of energy resources vital importance is imparted to the efficiency of production and consumption of the energy, as well as to energy saving techniques. A most frequent solution in this sphere is the installation of heat exchange skids (utilizer boilers, recuperators, waste gas heaters). Naturally, the requirements to the heat exchange equipment are similar to those of the main equipment: they are high efficiency and reliability, failure freedom etc.For fluid heat exchangers the power consumption for overcoming of friction and resistance (circulation flow energy) occuring during the fuid flow through the heat exchanger are generally negligible as compared with the respective calorific transfer. Accordingly, the influence of the consumed power for compensation of friction and resistance are rarely a crucial factor. But as for gaseous media heat exchangers the consumption of the mechanical energy for friction overcoming can rather easily reach values comparable with the value of the calorific transfer. Thereby it is necessary to remember that in the majority of industrial plants the mechanical energy "costs" are by several times (usually 3-5) more "expensive" than the equivalent thermal energy. 10.7463/0113.0532996 2It is easy to demonstrate that for the majority of channel shapes used to construct heat exchange surfaces the specific thermal load of the surface can be increased by the velocity increase of the coolant and the thermal load change is proportional to the velocity change raised to power close to 1.The energy input for the overcoming friction is also increased along with the growth of the flow velocity but it is generally changed proportionally to second power of the velocity. This is the characteristic feature of the correlation of the parameters of the calorific load and the friction (power for coolant pumping) which determines many features of heat exchangers of different classes. To compare surfaces with various ways of the heat exchange intensification a correlation is introduced between the efficiency growth of the heat transfer (correlation of Nusselt number on a surface with heat transfer intensifiers with Nusselt number on a smooth surface) and the resistance growth with the introduction of transfer intensifiers. This correlation is called Reynolds analogy with the following

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Section: Expe Ri Mental R Esultssupporting

confidence: 70%

“…In particular it is the case when vortices are generated at washing of a relief in the shape of hemispherical cavities (dimples) and projections (see, e.g. papers [7,8,9,10]). …”

Section: Reynolds Analogymentioning

confidence: 99%

Experimental study of parameters of surfaces coated with regular relief

Burtsev¹,

Vasil'ev²,

Vinogradov³

et al. 2013

S&E BMSTU

View full text Add to dashboard Cite

show abstract

“…Studies of the flow in channels with intensifiers in the form of concavities were considered in the researches [2][3][4], where it was experimentally established that heat exchange surfaces with spherical concavities significantly (1.5-4.5 times) increase heat exchange with a moderate increase of hydraulic resistance.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of heat exchange in discrete-rough channels at flow superimposed oscillations

Dzelzītis

Sidenko

2019

Engineering for Rural Development

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At present great attention is given to a problem of research of hydrodynamics and heat exchange in pulsating flows. Experimental studies for the flow in smooth channels show that pulsation of fluid flow significantly affects heat transferring and can be accompanied by both reduction and increasing in the intensity of heat exchange. However, at the present day, there is little reliable information about the effect of a pulsating flow on heat transferring in channels with discrete roughness. Thus, detection of regularities in heat exchanging processes of such flows in discretely rough channels is an actual problem for today. In this paper the results of numerical simulation of heat exchange in smooth and discrete-rough channels with a pulsating motion of fluid in them are presented. It is revealed that in the pulsating flow the instantaneous values of the heat exchange coefficient change with the change in the instantaneous values of the Reynolds numbers. Three zones of influence of the pulsing flow on the heat exchange in the channels are established. In the first area, with the Strouhal numbers 0 < Sh < 2, increasing in the average value of heat exchange in 10-15 % is observed. In the second area 2 < Sh < 4.3, its decreasing in 10-15 %. In the third area, 4.3 < Sh < 6, the average value of the heat exchanging value becomes almost the same as for the case of a stationary flow.

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“…This relation was experimentally proven for air in and around Pr=0.7. At the same time some researchers consider influence of recovery factor from Reynolds, Mach and Prandtl numbers, injection/suction into/from the boundary layer, shape and relief of streamlined surface [5][6][7][8][9][10][11]. These results show that recovery factor can significantly differ from the mentioned approximation.…”

Section: Introductionmentioning

confidence: 99%

Adiabatic wall temperature and heat transfer coefficient influenced by separated supersonic flow

et al. 2017

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Abstract. Investigations of supersonic air flow around plane surface behind a rib perpendicular to the flow direction are performed. Research was carried out for free stream Mach number 2.25 and turbulent flow regime -Rex>2·10 7 . Rib height was varied in range from 2 to 8 mm while boundary layer thickness at the nozzle exit section was about 6 mm. As a result adiabatic wall temperature and heat transfer coefficient are obtained for flow around plane surface behind a rib in contrast with the flow around plane surface without any disturbances.

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Effect of vortex flows at surface with hollow-type relief on heat transfer coefficients and equilibrium temperature in supersonic flow

Cited by 18 publications

References 1 publication

Experimental study of parameters of surfaces coated with regular relief

Experimental study of parameters of surfaces coated with regular relief

Numerical simulation of heat exchange in discrete-rough channels at flow superimposed oscillations

Adiabatic wall temperature and heat transfer coefficient influenced by separated supersonic flow

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