Turbulent Heat Transfer in a Revolving Square-Sectioned Tube:
01 Apr 1980-Archive: Journal of Mechanical Engineering Science 1959-1982 (vols 1-23) (SAGE Publications)-Vol. 22, Iss: 2, pp 95-101
TL;DR: In this paper, it is demonstrated that rotation about a parallel axis enhances the forced convection heat transfer, and a correlating equation for assessing this effect is proposed, and the results have application for the assessment of heat transfer in certain gas-cooled electrical machine rotors.
Abstract: An investigation of turbulent heat transfer in a revolving square-sectioned tube is reported in this paper. It is demonstrated that rotation about a parallel axis enhances the customary forced convection heat transfer, and a correlating equation for assessing this effect is proposed. The range of parameters covered in the experiments permit the results to have application for the assessment of heat transfer in certain gas-cooled electrical machine rotors.
Citations
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TL;DR: In this article, the effect of motion of the orbiting scroll on the convective heat transfer in the scroll wraps was investigated and quantitatively analyzed and applied to the simulation of compression process in scroll compressor.
Abstract: This paper describes an experimental study on the convective heat transfer inside the scroll compressor. An experimental refrigeration system is composed with extensive instrumentations in the compressor that is operated at variable speeds. The 13 thermocouples installed inside the compressor monitor the temperatures of the scroll wrap during compression process of refrigerant. The temperature and the pressure of refrigerant at suction, and the pressure at discharge ports are measured, and applied to the numerical simulation as the operating condition parameters. The temperature measured at the discharge port is used to verify the simulation result with relevant heat transfer coefficient. This paper describes the effect of motion of the orbiting scroll on the convective heat transfer in the scroll wraps. Separate experiments are performed to investigate the heat transfer in such a peculiar physical condition. With this experimental result, the effect of the oscillation of the wall on the heat transfer is quantitatively analyzed and applied to the simulation of compression process in scroll compressor. The whole consecutive compression processes in the scroll compressor is simulated in detail by solving equations of mass and energy balance for the refrigerant. The modified heat transfer coefficient correlation considering the effect of motion of the orbiting scroll predicts the discharge temperature better than other typical heat transfer coefficients.
60 citations
TL;DR: In this article, the combined heat transfer of convection and radiation in rectangular ducts rotating in a parallel mode was investigated numerically in detail, and the coupled momentum and energy equations were solved by the DuFort-Frankel numerical scheme to examine the interactions of the convection with radiation.
23 citations
TL;DR: In this article, rotation-induced secondary flow and mixed convection heat transfer in the entrance region of rectangular ducts rotating about a parallel axis are investigated. And the authors show that the rotational effect in an iso-flux duct is more significant than that in an isothermal flux, while the effect vanishes in isothermal ducts.
21 citations
01 Jan 1989
TL;DR: A generalized one-dimensional computer code for analyzing the flow and heat transfer in the turbomachinery cooling passages was developed in this paper, which is capable of handling rotating cooling passages with turbulators, 180 degree turns, pin fins, finned passages, bypass flows, tip cap impingement flows, and flow branching.
Abstract: A generalized one-dimensional computer code for analyzing the flow and heat transfer in the turbomachinery cooling passages was developed. This code is capable of handling rotating cooling passages with turbulators, 180 degree turns, pin fins, finned passages, by-pass flows, tip cap impingement flows, and flow branching. The code is an extension of a one-dimensional code developed by P. Meitner. In the subject code, correlations for both heat transfer coefficient and pressure loss computations were developed to model each of the above mentioned type of coolant passages. The code has the capability of independently computing the friction factor and heat transfer coefficient on each side of a rectangular passage. Either the mass flow at the inlet to the channel or the exit plane pressure can be specified. For a specified inlet total temperature, inlet total pressure, and exit static pressure, the code computers the flow rates through the main branch and the subbranches, flow through tip cap for impingement cooling, in addition to computing the coolant pressure, temperature, and heat transfer coefficient distribution in each coolant flow branch. Predictions from the subject code for both nonrotating and rotating passages agree well with experimental data. The code was used to analyze the cooling passage of a research cooled radial rotor.
16 citations
References
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01 Jun 1979
TL;DR: In this paper, the combined influence of Coriolis acceleration and centripetal buoyancy on heat transfer in a cylindrical tube which rotates about an axis orthogonal to its axis of symmetry was investigated.
Abstract: This paper reports the results of an experimental study of the combined influence of Coriolis acceleration and centripetal buoyancy on heat transfer in a cylindrical tube which rotates about an axis orthogonal to its axis of symmetry. It is demonstrated that for a radially outward flow, Coriolis acceleration tends to improve heat transfer. However the Coriolis-induced improvement to heat transfer may be nullified and reversed due to centripetal buoyancy and this is demonstrated. Proposals are made which permit an overall assessment of these two interacting effects to be made. The implications of the results reported in relation to the design of conventionally cooled turbine rotor blades are discussed.
62 citations
TL;DR: In this paper, the influence of rotation on the laminar asymptotic velocity and temperature profiles obtained when fluid flows through a vertical tube which rotates about a parallel axis with uniform angular velocity, and which is subjected to a uniform temperature gradient.
Abstract: This paper presents an investigation into the influence of rotation on the laminar asymptotic velocity and temperature profiles obtained when fluid flows through a vertical tube which rotates about a parallel axis with uniform angular velocity, and which is subjected to a uniform temperature gradient. Rotation induces secondary free convection flow in the plane perpendicular to the axis resulting in non-symmetrical axial-velocity and temperature profiles which modify the solved using a series expansion in ascending powers of the rotational Rayleigh number, the resulting solution being approximate and valid only for low rates of heating.
35 citations
TL;DR: In this paper, a forced convective heat transfer in a straight pipe rotating around a parallel axis with a large angular velocity has been studied by assuming an effective secondary flow due to buoyancy.
34 citations
TL;DR: The local and mean heat transfer characteristics have been studied experimentally for air flowing turbulently in the entrance region of a circular duct revolving about a horizontal axis parallel to the duct axis.
31 citations
TL;DR: In this paper, the authors analyzed the effect of secondary flow on the resistance coefficient and the Nusselt number in terms of Re and Δ (Re = Reynoldsnumber, Δ = inertiaforce/bodyforce).
24 citations