MATHEMATICAL MODEL OF DETERMINATION AND ANALYSIS OF HEAT EXCHANGE IN ELEMENTS OF DIGITAL TECHNOLOGY DEVICES

V.I. Havrysh

Èlektron. model. 2021, 43(4):37-50
https://doi.org/10.15407/emodel.43.04.037

ABSTRACT

A mathematical model of heat exchange analysis between an isotropic two-layer plate heated by a point heat source concentrated on the conjugation surfaces of layers and the environment has been developed. To do this, using the theory of generalized functions, the coefficient of thermal conductivity of the materials of the plate layers is shown as a whole for the whole system. Given this, instead of two equations of thermal conductivity for each of the plate layers and the conditions of ideal thermal contact, one equation of thermal conductivity in generalized derivatives with singular coefficients is obtained between them. To solve the boundary value problem of thermal conductivity containing this equation and boundary conditions on the boundary surfaces of the plate, the integral Fourier transform was used and as a result an analytical solution of the problem in images was obtained. An inverse integral Fourier transform was applied to this solution, which made it possible to obtain the final analytical solution of the original problem. The obtained analytical solution is presented in the form of an improper convergent integral. According to Simpson's method, numerical values  of this integral are obtained with a certain accuracy for given values  of layer  thickness, spatial coordinates, specific power of a point heat source, thermal conductivity of structural materials of the plate and heat transfer coefficient from the boundary surfaces of the plate. The material of the first layer of the plate is copper, and the second is aluminum. Computational programs have been developed to determine the numerical values of temperature in the given structure, as well as to analyze the heat exchange between the plate and the environment due to different temperature regimes due to heating the plate by a point heat source concentrated on the conjugation surfaces.  Using these programs, graphs are shown that show the behavior of curves constructed using numerical values of the temperature distribution depending on the spatial coordinates. The obtained numerical values of temperature indicate the correspondence of the developed mathematical model of heat exchange analysis between a two-layer plate with a point heat source focused on the conjugation surfaces of the layersand the environment, the real physical process.

KEYWORDS

heat transfer, isotropic two-layer plate, thermal conductivity, temperature field, heat-insulated surface, perfect thermal contact.

REFERENCES

  1. Carpinteri, A. and Paggi, M. (2008), “Thermoelastic mismatch in nonhomogeneous beams”, Eng. Math., Vol. 61, no 2–4, pp. 371–384.
    https://doi.org/10.1007/s10665-008-9212-8
  2. Havrysh, V.I. and Fedasjuk, D.V. (2012), Modelling of temperature regimes in piecewise-homogeneous structures, Publishing house of Lviv Politechnic National University.
  3. Otao, Y., Tanigawa, O. and Ishimaru, O. (2000), “Optimization of material composition of functionality graded plate for thermal stress relaxation using a genetic algorith”, Therm. Stresses, Vol. 23, pp. 257–271.
    https://doi.org/10.1080/014957300280434
  4. Havrysh, V.I., Kolyasa, L.I. and Ukhanka, O.M. (2019), “Determination of temperature field in thermally sensitive layered medium with inclusions”, Scientific Bulletin of the National Chemical University, 1, pp. 94–100.
    https://doi.org/10.29202/nvngu/2019-1/5
  5. Kikoin, I.K. (1976), Tablitsy fizicheskikh velichin [Tables of physical quantities], Atomizdat, Moscow, USSR.
  6. Koliano, Iu.M. (1992). Metody teploprovodnosti i termouprugosti neodnorodnogo tela [Methods of thermal conductivity and thermoelasticity of an inhomogeneous body], Naukova Dumka, Kyiv, Ukraine.
  7. Korn, G. and Korn, T. (1977), Spravochnik po matematike dlia nauchnykh rabotnikov i inzhenerov [A guide to mathematics for scientists and engineers], Nauka, Moscow, USSR.
  8. Nemirovskii, Iu.V. and Iankovskii, A.P. (2007), “Asymptotic analysis of the problem of unsteady heat conduction of layered anisotropic inhomogeneous plates under boundary conditions of the first and third kind on the front surfaces”, Matematychni metody ta fizyko-mekhanichni polya, 50, no 2, pp. 160–175.
  9. Noda, N. (1991), “Thermal stresses in materials with temperature-dependent properties”, Applied Mechanics Reviews, 44, pp. 383–397.
    https://doi.org/10.1115/1.3119511
  10. Havrysh, V.I., Baranetskiy, Ya.O. and Kolyasa, L.I. (2018), “Investigation of temperature modes in thermosensitive non-uniform elements of radioelectronic devices”, Radio electronics, computer science, management, 3, no 46, pp. 7–15.
    https://doi.org/10.15588/1607-3274-2018-3-1
  11. Podstrigach, Ia.S., Lomakin, V.A. and Koliano, Iu.M. (1984), Termouprugost tel neodnorodnoi struktury [Thermoelasticity of bodies of inhomogeneous structure], Nauka, Moscow, USSR.
  12. Tanigawa, Y. and Otao, Y. (2002), “Transient thermoelastic analysis of functionally gra­ded plate with temperature-dependent material properties taking into account the thermal radiation”, Nihon Kikai Gakkai Nenji Taikai Koen Ronbunshu, Vol. 2, pp. 133–134.
    https://doi.org/10.1299/jsmemecjo.2002.2.0_133
  13. Tanigawa, Y., Akai, T. and Kawamura, R. (1996), “Transient heat conduction and thermal stress problems of a nonhomogeneous plate with temperature-dependent material properties”, Therm. Stresses, Vol. 19, no 1, pp. 77–102.
    https://doi.org/10.1080/01495739608946161
  14. Turii, O. (2008), “Nonlinear contact-edge thermomechanics problem for an irradiated two-layer plate connected by an intermediate layer”, Fizyko-matematychne modeliuvannia ta informatsiini tekhnolohii, 8, pp. 118–132.
  15. Yangian, Xu. and Daihui, Tu. (2009), “Analysis of steady thermal stress in a ZrO2/FGM/ Ti-6Al-4V composite ECBF plate with temperature-dependent material properties by NFEM”, 2009-WASE Int. Conf. on Informa. Eng., Vol. 2–2, pp. 433–436.
    https://doi.org/10.1109/ICICTA.2009.842

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