Among nanotechnology-based thermal insulation materials thermodynamic performance of nano-ceramic coatings generates intensive discussions. Complete agreement has not been found yet about the mechanism of their insulating effect. In the Laboratory of Building Materials and Building Physics at Széchenyi István University (Győr, Hungary) heat transfer resistance experiments have been performed in order to describe thermodynamic processes inside nano-ceramic coatings. Previous studies finding after new measurements conducted in 2016-2017 also supported the former assumption that in case of nano-ceramic coatings convective heat transfer coefficient might be taken into account in a different way. Results also showed that thermal insulating effect of nano-ceramic coatings could be caused by a relatively high surface heat transfer resistance.
From nanotechnology-based thermal insulation materials nano-ceramic thermal insulation coatings are generally considered to be the most critical because of contradictory technical data that could be founded in special literature. Complete agreement had not been already found about the mechanism how does their insulating effect take. In the Laboratory of Building Materials and Building Physics at Széchenyi István University (Győr, Hungary) several thermodynamic tests were made in order to find out thermodynamic process inside this material. Several building structures with different order of layers were tested with heat flow meter. Results showed that convective heat transfer coefficient cannot be taken account in usual way using this material as thermal insulation.
predicated on Griffith’s fracture theory [ 15 ] which, consistent with the first law of thermodynamics, postulates that the reduction in strain energy because of crack propagation is employed to form new crack surfaces. This hypothesis is valid for brittle
Authors:Evgeniy V. Kulish, Marat M. Abashev, Anna Ivannikova, and Alexey Schenyatsky
Numerical-analytical methods based on variation approach to the tasks of mechanics of deformable solid, liquid, gas, hydro- and thermodynamics, multilinked contact and on analytical decisions of loosely-coupled tasks are presented in this paper. The suggested numerical-analytical method allows investigating on high technological level the high-strength joints with guaranteed interference (pressed, hydropressed, thermal, multilayered, autofrettaged, multi-contact (polyjoints)) at various stages of life cycle, except for recycling. Method allow: to determine mode of deformation, joint loading capacity in view of technology factor influence; to calculate parameters of technological processes with the diverse contact effects proceeding in joints, assembled by various methods.