Evaluation of nusselt number for a flow in a microtube with constant heat flux including axial conduction, viscous dissipation and second-order slip model

2010-09-28
Çetin, Barbaros
Bayer, Özgür
In this paper, the fully-developed temperature profile and corresponding Nusselt value is determined analytically for a gaseous flow in a microtube with a thermal boundary condition of constant wall heat flux. The flow assumed to be laminar, and hydrodynamically and thermally fully developed. The fluid is assumed to be constant property and incompressible. The effect of rarefaction, viscous dissipation and axial conduction, which are important at the microscale, are included in the analysis. Second-order model is used for the slip-flow and temperature jump boundary conditions for the implementation of the rarefaction effect. Closed form solutions for the temperature field and the fully-developed Nusselt number is derived as a function of Knudsen number, Brinkman number and Peclet number.

Suggestions

Critical behaviour of the dielectric constant for the smectic AC* transition under the electric field in ferroelectric liquid crystals
Yurtseven, Hasan Hamit (2012-01-01)
The temperature dependencies of the dielectric constant and the tilt angle (order parameter) are calculated under the electric field for the smectic A-smectic C* (AC*) transition in 4-(3-methyl-2-chlorobutanoyloxy)-4'-heptyloxybiphenyl (A7). The dielectric constant is fitted to the experimental data by using our mean field model with the biquadratic coupling between the spontaneous polarisation P and the tilt angle theta. Our results show that the mean field model with the P-2 theta(2) coupling describes sa...
Analytical solution of thermally developing microtube heat transfer including axial conduction, viscous dissipation, and rarefaction effects
Barışık, Murat; Yazıcıoğlu, Almıla Güvenç; Çetin, Barbaros; Kakaç, Sadık (Elsevier BV, 2015-10)
The solution of extended Graetz problem for micro-scale gas flows is performed by coupling of rarefaction, axial conduction and viscous dissipation at slip flow regime. The analytical coupling achieved by using Gram-Schmidt orthogonalization technique provides interrelated appearance of corresponding effects through the variation of non-dimensional numbers. The developing temperature field is determined by solving the energy equation locally together with the fully developed flow profile. Analytical solutio...
Calculation of the damping constant and the order parameter for the lattice mode in ferroelectric PbTiO3
Kiraci, A.; Yurtseven, Hasan Hamit (2013-07-25)
The temperature dependences of the damping constant and the order parameter are calculated for the lattice mode of E (1TO) in PbTiO3 using the experimental data by the pseudospin- phonon coupled model and the enrgy fluctuation model. Calculation of the damping constant of soft mode is performed in the temperature range of 400- 490 degrees C close to the ferroelectric- paraelectric transition (T-C= 493 degrees C) in PbTiO3. By relating the frequency to the order parameter, the temperature dependence of the R...
Calculation of the Damping Constant and the Relaxation Time for the Soft-Optic and Acoustic Mode in Hexagonal Barium Titanate
Yurtseven, Hasan Hamit (2012-01-01)
The temperature dependence of the damping constant is calculated below the transition temperature (T-0 = 222K) in the ferroelectric phase of hexagonal barium titanate. The damping constant of the coupled soft-optic and acoustic mode which causes an intense central peak in the light scattering spectra, is calculated using the soft mode-hard mode coupling model and the energy fluctuation model for barium titanate.
A numerical study of single-phase convective heat transfer in microtubes for slip flow
Sun, Wei; Kakac, Sadik; Yazicioglu, Almila G. (2007-11-01)
The steady-state convective heat transfer for laminar, two-dimensional, incompressible rarefied gas flow in the thermal entrance region of a tube under constant wall temperature, constant wall heat flux, and linear variation of wall temperature boundary conditions are investigated by the finite-volume finite difference scheme with slip flow and temperature jump conditions. Viscous heating is also included, and the solutions are compared with theoretical results where viscous heating has been neglected. For ...
Citation Formats
B. Çetin and Ö. Bayer, “Evaluation of nusselt number for a flow in a microtube with constant heat flux including axial conduction, viscous dissipation and second-order slip model,” Shangai, China, 2010, p. 1, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/74479.