scholarly journals Hot-wire measurement in turbulent flow behind a parallel-line heat source

PAMM ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 493-494
Author(s):  
Pavel Antos ◽  
Vaclav Uruba
Keyword(s):  
Heat Source ◽  
Turbulent Flow ◽  
Parallel Line ◽  
Hot Wire ◽  
Line Heat Source

Thermodynamic behaviour of microstretch viscoelastic solids with internal heat source

2014 ◽  
Vol 92 (5) ◽  
pp. 425-434 ◽  
Author(s):  
Sunita Deswal ◽  
Renu Yadav
Keyword(s):  
Heat Source ◽  
Normal Mode Analysis ◽  
Generalized Thermoelasticity ◽  
Internal Heat ◽  
Internal Heat Source ◽  
Mode Analysis ◽  
Moving Heat Source ◽  
Line Heat Source ◽  
Epoxy Material ◽  
Mech Phys Solid

The dynamical interactions caused by a line heat source moving inside a homogeneous isotropic thermo-microstretch viscoelastic half space, whose surface is subjected to a thermal load, are investigated. The formulation is in the context of generalized thermoelasticity theories proposed by Lord and Shulman (J. Mech. Phys. Solid, 15, 299 (1967)) and Green and Lindsay (Thermoelasticity, J. Elasticity, 2, 1 (1972)). The surface is assumed to be traction free. The solutions in terms of displacement components, mechanical stresses, temperature, couple stress, and microstress distribution are procured by employing the normal mode analysis. The numerical estimates of the considered variables are obtained for an aluminium–epoxy material. The results obtained are demonstrated graphically to show the effect of moving heat source and viscosity on the displacement, stresses, and temperature distribution.

scholarly journals Estimation of thermal conductivity of short pastry biscuit at different baking stages

2014 ◽  
Vol 45 (2) ◽  
pp. 64 ◽  
Author(s):  
Chiara Cevoli ◽  
Angelo Fabbri ◽  
Simone Virginio Marai ◽  
Enrico Ferrari ◽  
Adriano Guarnieri
Keyword(s):  
Thermal Conductivity ◽  
Thermal Processing ◽  
Physical Property ◽  
Physical Models ◽  
Hot Wire ◽  
Line Heat Source ◽  
Food Material ◽  
Wire Method ◽  
Thermal Conductivity Probe

Thermal conductivity of a food material is an essential physical property in mathematical modelling and computer simulation of thermal processing. Effective thermal conductivity of non-homogeneous materials, such as food matrices, can be determined experimentally or mathematically. The aim of the following research was to compare the thermal conductivity of short pastry biscuits, at different baking stages (60-160 min), measured by a line heat source thermal conductivity probe and estimated through the use of thermo-physical models. The measures were carried out on whole biscuits and on powdered biscuits compressed into cylindrical cases. Thermal conductivity of the compacted material, at different baking times (and, consequently at different moisture content), was then used to feed parallel, series, Krischer and Maxwell-Eucken models. The results showed that the application of the hot wire method for the determination of thermal conductivity is not fully feasible if applied directly to whole materials due to mechanical changes applied to the structure and the high presence of fats. The method works best if applied to the biscuit component phases separately. The best model is the Krischer one for its adaptability. In this case the value of biscuit thermal conductivity, for high baking time, varies from 0.15 to 0.19 Wm<sup>–1</sup> K<sup>–1</sup>, while the minimum, for low baking time, varies from 0.11 to 0.12 Wm<sup>–1</sup> K<sup>–1</sup>. These values are close to that reported in literature for similar products.

Effects of Wire Length in Turbulence Investigations with a Hot-Wire Anemometer

1954 ◽  
Vol 5 (1) ◽  
pp. 1-24 ◽  
Author(s):  
F. N. Frenkiel
Keyword(s):  
Turbulent Flow ◽  
Correlation Coefficients ◽  
Random Processes ◽  
Mathematical Treatment ◽  
Wire Length ◽  
Hot Wire ◽  
The Wire

SummaryThe paper discusses the influence of wire length on the characteristics of a turbulent flow as measured with a hot-wire anemometer. Most of the mathematical treatment can be directly applied to other problems of length correction, such as may occur, for instance, in problems of astrophysical turbulence, as well as to some problems related to measurements of random processes. The discussion will, however, use the example of a hot-wire anemometer with particular attention to the influence of the length of the wire on the measurement of the intensity of turbulence, correlation coefficients, and scale and microscale of turbulence.

scholarly journals Development of a Heat Source Model for Narrow-gap Hot-wire Laser Welding

2013 ◽  
Vol 31 (4) ◽  
pp. 82s-85s ◽  
Author(s):  
Rittichai Phaonaim ◽  
Masayuki Yamamoto ◽  
Kenji Shinozaki ◽  
Motomichi Yamamoto ◽  
Kota Kadoi
Keyword(s):  
Heat Source ◽  
Laser Welding ◽  
Source Model ◽  
Narrow Gap ◽  
Hot Wire ◽  
Heat Source Model

Measurements with a pulsed-wire and a hot-wire anemometer in the highly turbulent wake of a normal flat plate

1976 ◽  
Vol 77 (3) ◽  
pp. 473-497 ◽  
Author(s):  
L. J. S. Bradbury
Keyword(s):  
Turbulent Flow ◽  
Flat Plate ◽  
Flow Direction ◽  
Operating Conditions ◽  
Turbulent Intensity ◽  
Hot Wire ◽  
Mean Flow ◽  
Mean Velocity ◽  
The Mean ◽  
Better Than

This paper describes an investigation into the response of both the pulsed-wire anemometer and the hot-wire anemometer in a highly turbulent flow. The first part of the paper is concerned with a theoretical study of some aspects of the response of these instruments in a highly turbulent flow. It is shown that, under normal operating conditions, the pulsed-wire anemometer should give mean velocity and longitudinal turbulent intensity estimates to an accuracy of better than 10% without any restriction on turbulence level. However, to attain this accuracy in measurements of turbulent intensities normal to the mean flow direction, there is a lower limit on the turbulent intensity of about 50%. An analysis is then carried out of the behaviour of the hot-wire anemometer in a highly turbulent flow. It is found that the large errors that are known to develop are very sensitive to the precise structure of the turbulence, so that even qualitative use of hot-wire data in such flows is not feasible. Some brief comments on the possibility of improving the accuracy of the hot-wire anemometer are then given.The second half of the paper describes some comparative measurements in the highly turbulent flow immediately downstream of a normal flat plate. It is shown that, although it is not possible to interpret the hot-wire results on their own, it is possible to calculate the hot-wire response with a surprising degree of accuracy using the results from the pulsed-wire anemometer. This provides a rather indirect but none the less welcome check on the accuracy of the pulsed-wire results, which, in this very highly turbulent flow, have a certain interest in their own right.

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