Damage Analysis of Composite Sheet Under Thermal Load

The goal of this research is to carry out a 3-dimensional finite detail approach evaluation of a composite plate cracked under thermal loading. The results of the mechanical properties of the composite, the orientation angle of the fibers, the geometric form of the plate, the thermal loading and the crack length had been studied to show their influence on the variation of the integral J. It is concluded that the integral J increases with the increase of crack size, temperature variation and reduce in fiber orientation perspective (e). To complete the work a probabilistic analysis was carried out.

Influence of Miller cycle on thermal load of high-boosted diesel engine

With the increase of the engine intensified degree, mechanical load and thermal load become to the two main factors limiting the engine to intensify. Application of Miller cycle, which can be realized by late intake valve closing (LIVC) and deeper late intake valve closing (DLIVC), has the potential to reduce the effective CR, mechanical load, and thermal load. In this paper, the effects of LIVC and DLIVC on the mechanical load and thermal load of a boosted DI diesel are experimentally compared. Compared to the original base case, the average cylinder temperature of LIVC and DLIVC is reduced by 90 and 52 K. The exhaust temperature of LIVC and DLIVC decreased by 26 and 14 K, and the maximum combustion pressure of LIVC and DLIVC decreased by 1.6 and 9.7 bar. The pumping losses of LIVC and DLIVC are reduced by more than 25%, while the actual cycle power does not decrease due to the late closing of the inlet valve. The fuel consumption rate decreased from 250.1 g/kWh of base case to 240 g/kWh of LIVC, reduced by 4.0%. The indicated thermal efficiency increased from 41.9% of base case to 43.7% and 42.5% of LIVC and DLIVC. Miller loss is only 2.55% with Miller inlet phase.

Multi-Objective Techno-Economic Optimization of Design Parameters for Residential Buildings in Different Climate Zones

The comprehensive approach for a building envelope design involves building performance simulations, which are time-consuming and require knowledge of complicated processes. In addition, climate variation makes the selection of these parameters more complex. The paper aims to establish guidelines for determining a single-family household’s unique optimal passive design in various climate zones worldwide. For this purpose, a bi-objective optimization is performed for twenty-four locations in twenty climates by coupling TRNSYS and a non-dominated sorting genetic algorithm (NSGA-III) using the Python program. The optimization process generates Pareto fronts of thermal load and investment cost to identify the optimum design options for the insulation level of the envelope, window aperture for passive cooling, window-to-wall ratio (WWR), shading fraction, radiation-based shading control, and building orientation. The goal is to find a feasible trade-off between thermal energy demand and the cost of thermal insulation. This is achieved using multi-criteria decision making (MCDM) through criteria importance using intercriteria correlation (CRITIC) and the technique for order preference by similarity to ideal solution (TOPSIS). The results demonstrate that an optimal envelope design remarkably improves the thermal load compared to the base case of previous envelope design practices. However, the weather conditions strongly influence the design parameters. The research findings set a benchmark for energy-efficient household envelopes in the investigated climates. The optimal solution sets also provide a criterion for selecting the ranges of envelope design parameters according to the space heating and cooling demands of the climate zone.

Device cooling features in wiggler synchrotron workstations

Construction of the 4+ generation Siberian circular photon source (SKIF synchrotron) has started in Novosibirsk. It will initially be equipped with six research workstations. For two stations, synchrotron radiation is generated by superconducting wigglers, whose radiation power approaches 49 kW, and the power density on the axis is 92 kW/mrad2. Most of the optical devices of the stations operate in a vacuum. The high energy density of the synchrotron beamline and the requirements for the values of thermal deformations lead to difficult conditions for the thermal management of optical elements. The article provides an overview of the applied and promising cooling systems; an example of a 3D calculation of a thermal diamond filter of workstation 1-5 is given, the limit for the thermal load of the filter, at which the temperature of the diamond plate will not exceed 600 °C, is estimated.

Minimization of power and energy consumption of mechatronic drives in robotics and technological equipment

The maximum instantaneous power consumption of robot drives determines the requirements for the energy supply system and the dimensions of the machine. For numerous machines, there are no technological restrictions on the types of applied motion laws and their numerical characteristics i.e. maximum speeds and accelerations. The type of the motion law and especially its parameters are traditionally determined according to the preferences of the design engineer without any justification, though some-times restrictions on maximum accelerations or speeds are considered. The restrictions on maximum accelerations are related to ensuring the strength and accuracy of the drive, and the restrictions on maximum speeds are related to the safety of personnel in the workplace. The motor power is selected according to the maximum value of the instantaneous power and thermal load, which depends on the duration of switching on. The article analyzes the ways of minimizing of this maximum (peak) of instantaneous power inside the cycle for different laws and different loads. The main parameter by which the maximum (peak) power is minimized for all types of laws is the acceleration and braking times. On the example of the most common motion laws, the dependence of instantaneous power and energy consumption on accelerating time and braking time for various types of loads are studied. In this article, the dependence of instantaneous power and energy consumption on accelerating time and braking time for various types of loads are studied on the example of the most common motion laws. The research results are intended to create a design technique for drives of modern equipment.