1778. Temperature measurement and internal flow heat transfer analysis for partially ionized argon

This work deals with the application of the Nelder-Mead simplex search method (SSM) to study a porous extended surface. At first, analytical expression for calculating the local temperature field has been derived using an implicit Runge-Kutta method. The heat transfer phenomenon is assumed to be governed by conductive, naturally convective and radiative heat transfer, whereas the diffusion of mass through the porous media is also taken into account. Then, using the SSM, critical parameters such as porosity, permeability, and thermal conductivities of the extended surface have been predicted for satisfying a prescribed temperature field. It is found that many alternative solutions can meet a given thermal requirement, which is proposed to offer the flexibility in selecting the material and regulating the thermal conditions. It is observed that the allowable error in the temperature measurement should be limited within 5%. It is also found that even with few temperature measurement points, very good reconstruction of the thermal field is possible using the SSM.

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Modal Inverse Frequency Response Heat Transfer Analysis for Estimation of Machine Tool Transient Thermal Loads

10.1115/imece2001/med-23332 ◽

2001 ◽

Author(s):

Youji Ma ◽

Jingxia Yuan ◽

Jun Ni

Keyword(s):

Heat Transfer ◽

Machine Tool ◽

Temperature Measurement ◽

Measurement Data ◽

Heat Transfer Analysis ◽

Thermal Loads ◽

Thermal Errors ◽

Machine Tool Structure ◽

Transient Thermal ◽

Modal Method

Abstract Thermal loads of internal and external sources cause thermal deformations of a machine tool structure and affect its accuracy. Software-based real-time error compensation method is an effective way to reduce the thermal errors. However, lack of knowledge of thermal loads impedes greater success. In this paper, a method of inverse heat transfer analysis is developed that, using temperature measurement data from multiple sensors mounted on a machine tool structure, the transient thermal loads of multiple heat sources can be estimated simultaneously. The method uses modal method and is carried out in frequency domain. The temperature measurement data are first transformed into frequency spectra through DFT. The modal method of inverse frequency response analysis is then used to obtain the thermal load spectra. Finally the thermal loads are recovered from their spectra through IDFT. The estimated thermal loads play crucial roles in estimating transient temperature fields and transient thermal errors of a machine tool structure. The issues of mode truncations and frequency truncations, and their effects on the efficiency and stability of the method are also discussed with simulation results. Finally, experimental results on a machining center column are presented.

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Flow/Heat Transfer Analysis and Shape Optimization of a Heat Exchanger with Internally Finned Tube

Transactions of the Korean Society of Mechanical Engineers B ◽

10.3795/ksme-b.2005.29.4.460 ◽

2005 ◽

Vol 29 (4) ◽

pp. 460-468 ◽

Cited By ~ 1

Author(s):

Juhee Lee ◽

Sanghwan Lee ◽

Hyo-Jae Lim ◽

Kyoungwoo Park

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Shape Optimization ◽

Finned Tube ◽

Heat Transfer Analysis ◽

Internally Finned Tube ◽

Flow Heat

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Literature Review of Single Phase Internal Flow Heat Transfer Correlations in Straight Circular Conduits

ASME/JSME 2011 8th Thermal Engineering Joint Conference ◽

10.1115/ajtec2011-44191 ◽

2011 ◽

Cited By ~ 1

Author(s):

Amanie N. Abdelmessih ◽

Erik C. McGuire

Keyword(s):

Heat Transfer ◽

Single Phase ◽

Internal Flow ◽

Closed Solution ◽

The Past ◽

Wide Range ◽

Flow Heat ◽

Heat Transfer Correlations ◽

Time Required ◽

Enormous Number

An enormous number of empirical and analytical closed solution, single phase, internal flow heat transfer correlations exist in the open literature. This article is a compilation of single phase internal convective heat transfer correlations in straight, circular conduits. These correlations cover convective internal flow of various Newtonian fluids under a wide range of heating conditions, and orientations for the different flow regimes. In the past some engineers extended the use of some correlations beyond their limits. The purpose of this article is to compile internal flow heat transfer correlations in one source, to alleviate time required by the practicing engineer to research the literature for correlations to meet specific conditions.

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Heat Transfer Predictions of Film Cooled Stationary Turbine Airfoils

Volume 4: Turbo Expo 2007, Parts A and B ◽

10.1115/gt2007-27497 ◽

2007 ◽

Cited By ~ 4

Author(s):

Gregory M. Laskowski ◽

Anil K. Tolpadi ◽

Michael C. Ostrowski

Keyword(s):

Heat Transfer ◽

Boundary Conditions ◽

Turbine Blade ◽

Film Cooling ◽

Internal Flow ◽

External Flow ◽

Heat Transfer Analysis ◽

Hot Gas ◽

Turbine Airfoils ◽

Film Cooling Holes

Conventional heat transfer design methods for high temperature gas turbine airfoils decouple the internal and external flow. Thermal boundary conditions from these decoupled analyses are applied to the blade surfaces to predict turbine life. Typically, the domain for the external flow includes the hot gas path and the film cooling holes while the domain for the internal flow includes the internal flow passages and film cooling holes. The solid blade itself couples the external and internal flow and heat transfer. Since film cooling flow physics can play a significant role on the overall turbine blade heat transfer, there has been increased interest in capturing these effects by including the hole geometry in the solution procedure. Ideally, the complete turbine blade heat transfer analysis would be provided by efficient CFD simulations for the coupled problem including the internal passages, film cooling holes and hot gas path. By prescribing both the external flow and internal flow inflow/outflow boundary conditions, the hole physics can be included in the solution. The current paper presents results obtained for coupled simulations of the NASA C3X vane and VKI rotor which models the internal passages, hole geometries and hot gas path. In both cases, cooling is achieved by rows of pressure-side, leading-edge and suction-side film cooling holes. The rows are independently fed by span-wise, constant area plenums. The former has a total of 152 cylindrical cooling holes whereas the later has a total of 110 cylindrical/shaped holes. In addition, the C3X vane consists of 10 internal radial cooling passages of cylindrical cross-section. The simulations were conducted with the Shear Stress Transport (SST) model on a grid that extended into the viscous sub-layer along all surfaces. The computed surface pressure and external heat transfer coefficient distributions at mid-span are compared to experimental data for both cases. Internal heat transfer predictions are also presented and discussed.

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