Thermal Slip Coefficient

In his original derivation Brock used a value of % for Cs, the thermal slip coefficient. More recent data by Ivchenko and Yalamov (1971) have shown that Cs = 1.147 for complete thermal accommodation. In Brock s equation... 

Sharipov F, Kalempa D (2004) Velocity slip and temperature jump coefficients for gaseous mixtures. II. Thermal slip coefficient. Phys Fluid 16(3) 759-764... 

Thermal slip coefficient determines the tangential velocity of gas near a solid surface due to a longitudinal gradient of the surface temperature. 

Analogous to the slip velocity between gas and particle at Kn above the continuum flow range discussed in Section A above, a temperature discontinuity exists close to the surface at high Kn. Such a discontinuity represents an additional resistance to transfer. Hence, transfer rates are generally lowered by compressibility and noncontinuum effects. The temperature jump occurs over a distance 1.996kl 2 — a )/Fva k + 1) (K2, Sll) where is the thermal accommodation coefficient, interpreted as the extent to which the thermal energy of reflected molecules has adjusted to the surface temperature. 

Thus, we take advantage of the accuracy, robustness and efficiency of the direct problem solution, to tackle the associated inverse heat transfer problem analysis [26, 27] towards the simultaneous estimation of momentum and thermal accommodation coefficients in micro-channel flows with velocity slip and temperature jump. A Bayesian inference approach is adopted in the solution of the identification problem, based on the Monte Carlo Markov Chain method (MCMC) and the Metropolis-Hastings algorithm [28-30]. Only simulated temperature measurements at the external faces of the channel walls, obtained for instance via infrared thermography [30], are used in the inverse analysis in order to demonstrate the capabilities of the proposed approach. A sensitivity analysis allows for the inspection of the identification problem behavior when the external wall Biot number is also included among the parameters to be estimated. 

The thermal creep coefficient Gj is also obtained from the Navier-Stokes equation, but applying the thermal slip botmdary condition (9). It is verified that this coefficient does not depend on the type of the cross section in... 

Here Cs. "t, and x are microscopic constants Cs. >. and t are called the slip coefficient, the thermal creep coefficient, and the temperature jump distance, respectively. All four constants have the dimension of a length and their... 

Using the integral transform method, Yu and Ameel [4] solved for Nu for flow in a rectangular microchannel subject to the constant temperature and slip flow boundary conditions. They did not include viscous dissipation in the work, but they included variable thermal accommodation coefficients. Similar to [7], they concluded that Kn, Pr,... 

At high temperature, TTF TCNQ is metallic, with a(T) oc T-2 3 since TTF TCNQ has a fairly high coefficient of thermal expansion, a more meaningful quantity to consider is the conductivity at constant volume phonon scattering processes are dominant. A CDW starts at about 160K on the TCNQ stacks at 54 K, CDW s on different TCNQ chains couple at 49 K a CDW starts on the TTF stacks, and by 38 K a full Peierls transition is seen. At TP the TTF molecules slip by only about 0.034 A along their long molecular axis. 

---