Time-Periodic Heating in Boussinesq-Stokes Suspension with Three Diffusing Components

The effect of time-periodic heating in Boussinesq-Stokes suspension with three diffusing components has been carried out for the linear case. The correction Rayleigh number is obtained by applying the perturbation method to effectually control the convective flow by varying amplitude and frequency of modulation, and the eigenvalues are obtained by the Venezian approach. The time-periodic heating has been carried out for three cases: symmetric, asymmetric, and modulating only the lower boundary. It is found that the system is stable for smaller values whereas unstable for moderate values of frequency of modulation.

Periodic Temperature Responses in a Thermal System Under a Periodic Heating

In this paper, the periodic temperature responses of a thermal system under a periodic heating input are studied. Using the implicit mapping method, periodic temperature responses varying with excitation frequency are predicted for different input amplitudes. The corresponding stability of the periodic responses are discussed through eigenvalue analysis. The experimental and numerical results of the periodic response are presented for comparison to the analytical results.

DETERMINATION OF THE DEPENDENCE OF CHANGE OF EMPERATURE OF THE EXHAUST GAS SYSTEM AT REDUCED TEMPERATURES

The aim of the study is to determine the relationship between the duration of the operation of the vehicle's power plant in idle mode and the temperature of the surfaces of the exhaust system. During engine operation, the temperature of individual components of the exhaust system was measured by means of thermocouples. The results obtained demonstrate that the dynamics of changes in the degree of heating of various parts of the exhaust system remains similar at different air temperatures. The dependence of the surface temperature of the exhaust system elements on time is built. The revealed regularities can be taken into account when developing various methods of periodic heating of the exhaust system.

Development of Novel Thermal Diffusivity Analysis by Spot Periodic Heating and Infrared Radiation Thermometer Method

A spot periodic heating method is a highly accurate, non-contact method for the evaluation of anisotropy and relative thermophysical property distribution. However, accurately evaluating thermal diffusivity is difficult due to the influence of temperature wave reflection from the whole surface of the sample. This study proposes a method to derive thermal diffusivity using a parameter table based on heat transfer equations using the concept of optimum distance between heating-point and measurement point. This method considers finite sample size, sensitivity distribution of infrared ray detector, intensity distribution of heating laser and sample thickness. In these results, the obtained thermal diffusivity of pure copper corresponded well with previous literature values. In conclusion, this method is considered highly effective in evaluating the thermal diffusivity in the horizontal direction.

Habitable worlds of merging stars

It is shown that W UMa-type and SX Phe-type stellar populations are both perfectly and uniquely suited for maintaining hyper-effective biopolymer chain reactions (BCR) on their planets once the planet is in the stellar habitable zone. W UMa-type stars are known to be contact binaries, and SX Phe-type stars are presumably post-binaries, i.e., products of stellar mergers. In case of the contact binaries, the eclipse-driven periodic heating/cooling of planetary surfaces has period-amplitude parameters that perfectly satisfy stringent conditions for maintaining BCR-like reactions. In case of the post-binaries, the stars pulsate with periods and amplitudes also perfectly suited for maintaining the reactions. Therefore, the ‘W UMa – SX Phe’ metamorphosis (from a contact binary to a post-binary, via the merger) seems to provide a potential biosystem reboot on planets in these systems.