اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدThermal contact resistance between two nanoparticles
239
0
0.0
(
0
)
تأليف
Gilberto Domingues
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We compute the thermal conductance between two nanoparticles in contact based on the Molecular Dynamics technique. The contact is generated by letting both particles stick together under van der Waals attractions. The thermal conductance is derived from the fluctuation-dissipation theorem and the time fluctuations of the exchanged power. We show that the conductance is proportional to the atoms involved in the thermal interaction. In the case of silica, the atomic contribution to the thermal conductance is in the range of 0.5 to 3 nW.K-1. This result fits to theoretical predictions based on characteristic times of the temperature fluctuation. The order of magnitude of the contact conductance is 1 mu W.K-1 when the cross section ranges from 1 to 10nm2.
قيم البحث
اقرأ أيضاً
We analyze the heat transfer between two nanoparticles separated by a distance lying in the near-field domain in which energy interchange is due to Coulomb interactions. The thermal conductance is computed by assuming that the particles have charge d
istributions characterized by fluctuating multipole moments in equilibrium with heat baths at two different temperatures. This quantity follows from the fluctuation-dissipation theorem (FDT) for the fluctuations of the multipolar moments. We compare the behavior of the conductance as a function of the distance between the particles with the result obtained by means of molecular dynamics simulations. The formalism proposed enables us to provide a comprehensive explanation of the marked growth of the conductance when decreasing the distance between the nanoparticles.
We report on the first model of a thermal transistor to control heat flow. Like its electronic counterpart, our thermal transistor is a three-terminal device with the important feature that the current through the two terminals can be controlled by s
mall changes in the temperature or in the current through the third terminal. This control feature allows us to switch the device between off (insulating) and on (conducting) states or to amplify a small current. The thermal transistor model is possible because of the negative differential thermal resistance.
In this paper, we address the issue of the stability of the thermal equilibrium of large quantum systems with respect to variations of the thermal contact between them. We study the Schrodinger time evolution of a free bosonic field in two coupled on
e-dimensional cavities after a sudden change of the contact between the cavities. Though the coupling we consider is thermodynamically small, modifying it has a considerable impact on the two-point correlation functions of the system. We find that they do not return to equilibrium but essentially oscillate with a period proportional to the length of the cavities. We compare this coupled cavities system with the perfect gas which is described by similar expressions but behaves very differently.
We report on experimental investigation of thermal contact resistance of the noncuring graphene thermal interface materials with the surfaces characterized by different degree of roughness. It is found that the thermal contact resistance depends on t
he graphene loading non-monotonically, achieving its minimum at the loading fraction of ~15 wt.%. Increasing the surface roughness by ~1 micrometer results in approximately the factor of x2 increase in the thermal contact resistance for this graphene loading. The obtained dependences of the thermal conductivity, thermal contact resistance, and the total thermal resistance of the thermal interface material layer on the graphene loading and surface roughness indicate the need for optimization of the loading fraction for specific materials and roughness of the connecting surfaces. Our results are important for developing graphene technologies for thermal management of high-power-density electronics.
We study interface thermal resistance (ITR) in a system consisting of two dissimilar anharmonic lattices exemplified by Fermi-Pasta-Ulam (FPU) model and Frenkel-Kontorova (FK) model. It is found that the ITR is asymmetric, namely, it depends on how t
he temperature gradient is applied. The dependence of the ITR on the coupling constant, temperature, temperature difference, and system size are studied. Possible applications in nanoscale heat management and control are discussed.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
