Interferometric Measurement of Heat Transfer above New Generation Foam Concrete

Abstract

The contribution is focused on investigating the heat transfer via natural convection which originated as an effect of changed air density by heating the horizontal sample in the area given. For this research we used samples of a new material made in the Russian Federation -the foam concrete which was reinforced by PET fibres. The samples were heated by an electric heating device from the bottom. The temperature fields originating above the horizontal sample surface were visualised by means of the holographic interferometric contactless method in real time. The holographic interferograms of the temperature field were analysed, and then the local heat transfer parameters were calculated: the heat transfer coefficient α, and the heat conductivity coefficient λ.

Influence of Different Strain Hardening Models on the Behavior of Materials in the Elastic–Plastic Regime under Cyclic Loading

“…The last relation shows that in the incremental theory of plasticity, the rate (increment) of plastic deformation is expressed as a function of instantaneous stress, strain rate and stress rate [ 40 , 41 , 42 , 43 , 44 , 45 ]: …”

“…The internal control variable is the kinematic stress tensor α which defines the actual position of the center of the plasticity area and it is related to the internal stress. Then, in purely kinematic hardening, the plasticity condition is expressed in the form of [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]: …”

“…p is expressed as a function of instantaneous stress, strain rate and stress rate [40][41][42][43][44][45]:…”

Theoretical Research of the Internal Gas Dynamics Processes of Measurements of Hot Air Curtain With Cross-Flow Fan

“…In this case methods of computation of gas dynamics widely used for aerodynamic flotation simulation in various technical devices are more preferable. Computational simulation is used both for studying the unsteady aerodynamics and heat exchange in operating (internal) spaces of devices [Khosrowpanah 1988, Kim 2008, Darmawan 2015, Sun 2015, Bako 2016, Baranov 2017, Sharfarets 2018, Pivarčiová 2019] and for calculation of shape and airstream axis course indoors after it is blown out of the air curtain [Diskin 2003, Menter 2003, Kruglova 2006, Frank 2014, Grigoriev 2016, Li 2016, Gilyazetdinov 2018, Diametrically 2019, Simulation 2019]. Computational studies of gas dynamic processes in an air curtain displacement volume are essential for device performance parameters estimation (air efficiency, noise level, narrowness and average temperature of exhausting flow, aerodynamics losses in air curtain flow channel) as well as for air curtain design optimization i.e.…”

Experimental assessment of the static stiffness of machine parts and structures by changing the magnitude of the hysteresis as a function of loading

“…Nowadays, not much attention is paid to the issue of stiffness. For example, with the production machines, the priority is given to the issue of thermal stability and the is-sue of component accuracy [1][2][3][4][5]. Of course, the stiffness is also an important property and it is investigated along with damping properties.…”