Numerical Approach of Symmetric Traveling Salesman Problem Using Simulated Annealing

The aim of this paper is to elaborate the performance of Simulated Annealing (SA) algorithm for solving traveling salesmen problems. In this paper, SA algorithm is modified by using the interaction between outer and inner loop of algorithm. This algorithm produces low standard deviation and fast computational time compared with benchmark algorithms from several research papers. Here SA uses a certain probability as indicator for finding the best and worse solution. Moreover, the strategy of SA as cooling to temperature ratio is still given. Thirteen benchmark cases and thirteen square grid symmetric TSP are used to see the performance of the SA algorithm. It is shown that the SA algorithm has promising results in finding the best solution of the benchmark cases and the squared grid TSP with relative error 0 - 7.06% and 0 – 3.31%, respectively. Further, the SA algorithm also has good performance compared with the well-known metaheuristic algorithms in references.

Irreversibility Analysis for Eyring–Powell Nanoliquid Flow Past Magnetized Riga Device with Nonlinear Thermal Radiation

The report contained in this article is based on entropy generation for a reactive Eyring–Powell nanoliquid transfer past a porous vertical Riga device. In the developed model, the impacts of viscous dissipation, thermophoresis alongside nonlinear heat radiation and varying heat conductivity are modelled into the heat equation. The dimensionless transport equations are analytically tackled via Homotopy analysis method while the computational values of chosen parameters are compared with the Galerkin weighted residual method. Graphical information of the various parameters that emerged from the model are obtained and deliberated effectively. The consequences of this study are that the temperature field expands with thermophoresis, Brownian motion and temperature ratio parameters as the modified Hartmann number compels a rise in the velocity profile. The entropy generation rises with an uplift in fluid material term as well as Biot and Eckert numbers whereas Bejan number lessens with Darcy and Eckert parameters.

Influences of Pressure ratio and Fluid Temperature on overall Cooling Performances of Ribbed Channel with Film Holes

The previous experiments of overall cooling performances were most conducted using simplified models and under the similar temperature ratio of mainstream to cooling air with real gas turbine operations, and ambient outlet pressure. To discuss the reliability of this type of experimental data, this paper exhibits two series of numerical simulations. Using a real E3 blade as model, which has two-pass rib-roughened channel with inclined film holes, numerical simulations are carried out at the same temperature ratio and pressure ratio, but different fluid temperatures including mainstream and cooling air, and different outlet pressure. The numerical results reveal two important conclusions: 1) At the same outlet pressure, the overall cooling effectiveness on PS is not sensitive to the fluid temperatures, but on SS in the region between two rows of film holes, a higher fluid temperature corresponds to a higher cooling effectiveness. 2) At the same pressure ratio of inlet to outlet, the overall cooling effectiveness on PS and SS is not sensitive to the outlet pressure and fluid temperature.

The Heat Transfer Coefficient Predictions in Engineering Applications

Most engineering applications have boundary layers; the convective transport of mass, momentum and heat normally occurs through a thin boundary layer close to the wall. It is essential to predict the boundary layer heat transfer phenomenon on the surface of various engineering machines through calculations. The experimental, analogy and numerical methods are the three main methods used to obtain convective heat transfer coefficient. The Reynolds analogy provides a useful method to estimate the heat transfer rate with known surface friction. In the Reynolds analogy, the heat transfer coefficient is independent of the temperature ratio between the wall and the fluid. Other methods also ignore the effect of the temperature ratio. This paper summarizes the methods of predicting heat transfer coefficients in engineering applications. The effects of the temperature ratio between the wall and the fluid on the heat transfer coefficient predictions are studied by summarizing the researches. Through the summary, it can be found that the heat transfer coefficients do show a dependence on the temperature ratio. And these effects are more obvious in turbulent flow and pointing out that the inaccuracy in the determination of the heat transfer coefficient and proposing that the conjugate heat transfer analysis is the future direction of development.

Inward and outward dust acoustic cylindrical and spherical waves interaction in four-component dusty plasma with nonthermal ions

A theoretical investigation by an all-inclusive adaptation of the PLK strategy is carried out in order to study the inward and outward interaction between two cylindrical and spherical dust acoustic solitary waves (DASWs) in an unmagnetized dusty plasma consisting of nonthermal distributed ions, negatively and positively charged dust grains along with electrons featuring Boltzmann’s distribution. The interactions and collisions between two cylindrical and spherical geometries at different time scales are studied. Also the combined effects of the nonthermality of ions, ion to electron temperature ratio as well as mass ratio of positive to negative dust grains have been studied in detail on the phase shifts raised due to collision. It has been seen that the properties of the cooperation of DASWs in cylindrical and spherical shaped are distinct.

Structural Characteristics of Ion Holes in Plasma

Ion holes refer to the phase-space structures where the trapped ion density is lower at the center than at the rim. These structures are commonly observed in collisionless plasmas, such as the Earth’s magnetosphere. This paper investigates the role of multiple parameters in the generation and structure of ion holes. We find that the ion-to-electron temperature ratio and the background plasma distribution function of the species play a pivotal role in determining the physical plausibility of ion holes. It is found that the range of width and amplitude that defines the existence of ion holes splits into two separate domains as the ion temperature exceeds that of the electrons. Additionally, the present study reveals that the ion holes formed in a plasma with ion temperature higher than that of the electrons have a hump at its center.

Compressor Maps and Coupling: Symmetry, Paradox, and Clarity

The most common compressor map framework, referred to here as the β-framework, will be shown to suffer from limitations that grow more troublesome in the multiple-map environment. When maps are coupled in series in the β-framework, it is very common to find operating points that are physically unrealizable, but these cannot generally be avoided without first generating them. A feasible situation is described in which the β-framework leads to an apparent physical paradox. In the proposed S-framework, the map itself is recast in terms of independent variables (corrected speed and exit corrected flow) and dependent variables (inlet corrected flow and temperature ratio). The propagation of information in map coupling is split into an upstream-marching corrected flow ‘flux’ and a downstream-marching temperature ‘flux’. Finding the equilibrium operating point requires only finding a simple intersection between curves. The S-framework is then developed further into a more compact S’-framework that exhibits a natural set of qualitative symmetries. The S- and S’-frameworks are shown to simplify compressor map expression, resolve the problems shown with the β-framework, and aid intuition with regard to off-design phenomena. The resolution of the paradox using the S’-framework is a new description of multistage compressor performance hysteresis.

Analisis Laju Aliran Udara dan Laju Aliran Massa Bahan Bakar Terhadap Beban Pembakaran Sampah pada Incinerator Berbahan Bakar Limbah Oli Bekas

<em>The amount of household waste and B3 from oil machine waste have been increasing along with the increasing of polulation and the number of vehicles.</em> <em>This waste can be used as a source of energy. The aim of this research was to analize the</em> <em>air flow rate and mass flow rate of fuel in the incinerator oil machine waste using a burner furnace by conducting several variations of the experiment with variations in air velocity of 10,4 m/s (B1), 13,4 m/s (B2) and 14,3 m/s (B3) and fuel flow rate of 0,00408 l/s (A1) and 0,00838 l/s (A2) with fuel valve openings 1/2 and 1/4. The test results showed that the highest temperature was 1021,5⁰C in the A2-B3 experiment with 45 minutes and the lowest temperature was obtained in the A1-B1 experiment which was 840,5⁰C at the same time. In the incinerator test, the burning of dry plastic waste weighing 12 kg of waste burns out in 34 minutes with a temperature ratio for the burner furnace which is 780,9⁰C and the incinerator chamber space is 480,7⁰C and the combustion rate is 21,42 kg/hour. the yield of residual combustion is 9,32% and the incinerator combustion eficiency is 90,68% and for dry leaf waste weighing 8 kg the waste is burnt out in 20 minutes with a burner furnace temperature ratio of 712,3⁰C and incinerator chamber space of 443, 2⁰C and the combustion rate of 24,24 kg / hour and the yield of combustion residue is 96,94%.</em>

The Measurement of Demographic Temperature Using the Sentiment Analysis of Data from the Social Network VKontakte

Social networks have a huge potential for the reflection of public opinion, values, and attitudes. In this study, the presented approach can allow to continuously measure how cold “the demographic temperature” is based on data taken from the Russian social network VKontakte. This is the first attempt to analyze the sentiment of Russian-language comments on social networks to determine the demographic temperature (ratio of positive and negative comments) in certain socio-demographic groups of social network users. The authors use generated data from the comments to posts from 314 pro-natalist groups (with child-born reproductive attitudes) and eight anti-natalist groups (with child-free reproductive attitudes) on the demographic topic, which have 9 million of users from all over Russia. The algorithm of the sentiment analysis for demographic tasks is presented in the article. In particularly, it was found that comments under posts are more suitable for analyzing the sentiment of statements than the texts of posts. Using the available data in two types of groups since 2014, we find an asynchronous structural shift in comments of the corpuses of pro-natalist and anti-natalist thematic groups. Interpretations of the evidences are offered in the discussion part of the article. An additional result of our work is two open Russian-language datasets of comments on social networks.