bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model-based simulation design for the students’ conceptual understanding of introductory thermodynamics
Authors: Meli Kalliopi , Koliopoulos Dimitrios 
Published: August 2019

Abstract
The present study refers to the design principles of an educational simulation for the introductory physics level and their application on a recently developed simulation (IGasES: Ideal Gas Educational Simulation) for classical thermodynamics and specifically for the First Law of Thermodynamics. These principles rely on three modeling aspects (physics teaching, learning and educational simulations) and their convergence for the construction of a model-based educational simulation. The study also reviews some of the issues that commonly used simulations encounter for the teaching and learning of this topic. For addressing these issues, we choose the energy chain model as a proper representation of a thermodynamic system for mediating between the phenomenology and the mathematical expression of the First Law. In conclusion, this study draws attention on the characteristics of the educational software rather than the way they are put in use and also to the modeling procedures than can facilitate the student’s conceptual understanding.
Towards a teacher dashboard design for interactive simulations
Authors: López Tavares D , Perkins K , Kauzmann M , Aguirre Velez C 
Published: August 2019

Abstract
The use of interactive simulations (sims) in physics education is increasing. Aside from direct observation, teachers currently lack options for gaining useful insights into how their students are using these sims. A teacher dashboard to analyze and visualize student interaction with sims holds promise for responding to teacher needs and providing opportunities for improved classroom implementation of such sims. In this work we present progress in the design and development of a teacher dashboard that analyzes and visualizes student interaction with sims. A survey of over 800 teachers was conducted to identify the types of information teachers’ perceive as useful and how they would use that information to guide instruction. Teacher report valuing information that helps them to review student performance, to improve the design of sim-centered activities, and to plan lessons. A prototype dashboard design informed by this survey is also presented, including data collected from student sim use during a college homework activity. Finally, we describe how this dashboard design can address teacher needs related to insights around sim-based activities. Future work will evaluate teacher opinions regarding their interpretation of the data visualizations and the dashboard design in general.
pml – a language for authoring and editing physics text
Authors: Lawrence Ian 
Published: August 2019

Abstract
Expressing physics on a web page with the fruitful precision required in order to best support learning tends to be a demanding technical task for authors and content curators. That is as a result of the need to adhere to various conventions, such as the spacing between numbers and units, and ensure that unhelpful distributions of words do not detract from meaning, such as splitting equations over lines, or placing number and unit on different lines, whatever the display device. In short, there is a lot to get right. Current standards in markup languages such as html do not lend much support to avoiding of these kinds of mis-steps. Some current techniques suggest a mixture of technologies, such as embedding LATeX via MathJax to represent equations, but this is inelegant, introduces dissipative friction into the authoring and editing systems, and results in extra difficulties in separating content from display technologies whilst ensuring representational consistency across the different technologies deployed. A system using this physics markup language can be implemented using standard web technologies (generating clean, standards-compliant and mobile-friendly html, with hooks for CSS, and relying only on JavaScript) and authoring can be in any text editor.
Learning Physics with Interactive Videos – Possibilities, Perception, and Challenges
Authors: Richtberg Stefan , Girwidz Raimund 
Published: August 2019

Abstract
Videos on YouTube are very popular among students and therefor the number of educational videos is growing. In general, such videos are a learning opportunity with unique features like visual highlighting or multiple representations and can be watched as often as you like. Moreover, videos can be used in many different ways: to repeat things, to learn something new, or for entertainment. Here the paper presents a study among n=260 German students to determine how often and why students are watching educational videos in Physics, Chemistry, and Biology. Furthermore, the study shows unfortunately that students often just watch learning videos passively; whereas, learning needs an active processing. So making already available online videos more interactive with tasks, questions, and quizzes can foster an active processing and students should perceive interactive videos as more helpful when learning online. To do so the paper presents the free and open source tool H5P, which can be easily used by every teacher to enrich learning videos with tasks, feedback, summaries, or additional information.
The Augmented Laboratory – a mixed reality setup for physics education
Authors: Rosi T , Onorato P , Oss S 
Published: August 2019

Abstract
We discuss an educational project, The Augmented Laboratory, aimed to bring innovation in educational physics laboratories in formal and informal contexts. It is based on the capability of obtaining 3D reconstructions of the physical world which can be visualized both live as the data is acquired and later on as interactive playbacks. The setup allows to obtain 3D tracking of multiple objects, to project data of interest directly on and around the objects used in a real experiment, and to introduce the new concept of “augmented experiments”. The setup was tested with a group of university students and as a scientific exhibit for hands-on activities.
Newton’s Law - A Theory of motion or force?
Authors: Goren Ehud , Galili Igal 
Published: August 2019

Abstract
Regular disciplinary instruction of introductory physics at high school often misses a holistic perspective of the subject matter, its structure and hierarchy. We have considered the domain of mechanics and provided such a perspective in a summative lecture by framing mechanics contents in discipline-culture framework. In the experimental teaching, we focused on Newton’s laws of motion as the nucleus of classical mechanics. Considering mechanics as a culture, that is, addressing the debate with periphery conceptions, caused students to appreciate the fact that mechanics is about theory of motion, while forces present only a certain conception to account for it.
Phenomenon-based learning and model-based teaching: Do they match?
Authors: Grusche Sascha 
Published: August 2019

Abstract
The goal of physics teaching is to guide students from their everyday conceptions and activities to scientific models and practices. In essence, there are two different ways toward that goal: Phenomenon-based instruction and model-based instruction. Phenomenon-based instruction has been characterised by subjectivity, affectivity, mediation, exploration, and restrained model use. By definition, model-based instruction must be described by diametrically opposed characteristics: objectivity, rationality, confrontation, hypothesis testing, and extensive model use. Thus, the physics teacher may think that the two methods of teaching and learning do not match. However, we will see that both methods can be combined to guide students stepwise from phenomena to models.
A Rapid 3D-Modeling Method for Impeller of Wind Turbine
Authors: Wu Weimin , Zhou Chuande , Liu Jingcheng , Wang Xiaomei , Yang Yonggang 
Published: August 2019

Abstract
It is a very important fundamental work that 3D-model of impeller for wind turbine can be achieved precisely, in order to enhance the credibility of CFD analysis in subsequent calculations. However, the current studies do not emphasize closely on the modeling with time-saving and high efficient. Therefore, one high efficient approach for geometric modeling of wind turbine impeller is proposed by this study, and the validity of logical framework and pseudo-code of each part correspondingly is confirmed through several applications upon modeling of impeller, with time-efficient to shape in the process-designed. Moreover, the validity concerning CFD solution is verified by CFD computations of wake of a wind turbine. Additionally, the high efficient approach is also suit for a wider spectrum in fluid machinery for the modeling of relevant entities, and especially for performing such optimal modeling associated with high efficiency, in terms of concise readjustment to grammar and related modeling operations in the logical framework proposed by this paper.
Study on Thermal Performance of Single-layer and Multi-layer Stone Aluminum Honeycomb Composite Panels
Authors: Wu Miaomiao , Liu Jiahao 
Published: August 2019

Abstract
The stone aluminum honeycomb composite panel is light in weight and large in ductility. It is a sustainable building thermal insulation material. It can be used as an insulation wall for ordinary buildings and prefabricated buildings, so that the exterior walls of the building can be light, high-strength and heat-insulated. However, the current application of stone aluminum honeycomb composite panels is still rare in practice, because the reasonable core size and number of layers with the best structural optimization, the least heat transfer, and the strongest applicability are difficult to determine. In this paper, the three basic heat transfer mechanisms of heat conduction, thermal convection and heat radiation of stone aluminum honeycomb composite panel structure are systematically analyzed. Under the premise of convective heat transfer of gas in honeycomb core cavity, the surface radiation exchange of honeycomb core cavity is established. The heat and the heat transfer of the cavity and the air in the cavity play a leading role in the heat transfer mechanism. The effects of parameters such as honeycomb core layer, core size, core height and core wall thickness on heat transfer performance under steady-state heat transfer conditions were studied by experimental methods. Stone aluminum honeycomb composite panels were tested under different temperature conditions. The equivalent thermal conductivity of the structure. Based on the ANSYS finite element analysis software, based on the experiment, the fluid-solid coupling heat transfer model of stone aluminum honeycomb composite board was established to simulate the steady-state heat transfer performance of composite sheets under single-layer and multi-layer honeycomb core materials, and to study the core body. The variation of the effective thermal conductivity under different boundary conditions and different geometric parameters, the simulation results are basically consistent with the experimental results, and the results of the empirical formula are also consistent. The results show that under the condition of satisfying the feasibility of the construction process within the fixed height, the height of the honeycomb core layer, the size of the core, and the height of the core can be appropriately reduced to reduce the thermal conductivity.
Numerical Simulation of Large Crude Oil Storage Tank Fire under Various Wind Speeds
Authors: Zhou Feng 
Published: August 2019

Abstract
In order to analyse the influence of the wind speed on the fire characteristics and hazards of large crude oil storage tanks, this paper used the fire dynamics simulation software FDS to simulate the fire of a large crude oil storage tank under various wind speeds. The fire characteristics such as flame, smoke and temperature distributions of the tank under different wind speeds were studied. The thermal effects on the adjacent tank and the way that the firefighters cool the hazardous area were discussed. The results show that with the increase of the wind speed, the flame, smoke and temperature distributions shift and spread downwind. When tank fire occurs, the firefighters should set up movable firefighting water gun near the dangerous area and lay fire water hose to the burning tank and its neighbours, which provides a good preparation for the subsequent firefighting operation near the burning tank.
Coupled CFD-DEM Simulation of Tea Particles in a Cylinder Fixation Equipment
Authors: Luo Jie , Liu Yunwen 
Published: August 2019

Abstract
This paper presents a coupled CFD-DEM approach to simulate the process of tea fixation in a cylinder fixation equipment. We have carried out quantitative assessments of process conditions, such as rotation speed, number and height of lifter and drum tilt. The temperature and movement charatertristic of particles in the drum are obtained and analyzed. We assess the performance of our framework by employing temperature rising rate, which presents the efficiency of heat transfer between hot air and particles. An orthogonal experiment with four factors and three levels was designed, and the results show that the rotation speed and drum tilt have great influence on the temperature rising rate of tea particles, and the number and the height of lifter had little influence on the temperature rising rate. Finally, we have identified a lifter of 14 pieces and 70 cm height, a rotation speed of 20 r/min and a drum tilt of 3 degrees as a set of optimal operating conditions.
Numerical Simulation of Erosion of Valve Sealing Surface by High Speed Water Flow Based on ALE Method
Authors: Wang Dongdong , Yu Xinhai 
Published: August 2019

Abstract
With the development of modern industry, more and more valves need to be serviced under severe working conditions. Due to the high-speed flushing of working media, the failure of valve sealing surfaces is not uncommon. Based on the ALE (Arbitrary Lagrange-Euler) algorithm, LS-DYNA is used to simulate the erosion of the valve sealing surface material Stellite21 by high-speed water flow, and the damage degree of grid unit is judged by the damage parameter D. At the same time, the parameters of Stellite21 in the Johnson-Cook material model were first calibrated. In this paper, the impact dynamics simulations of different impact angles and different impact velocities were carried out and the material behaviour under different operation parameters of water jet is studied. It is found that with the increase of impact velocity, the erosion rate of materials has a significant increase. As impact angle increases, the erosion damage rate increases first and then decreases, and material has the maximum erosion damage rate at the impact angle of about 40°.
Design optimization and analysis of a vaned diffuser based on the one-dimensional impeller-diffuser throat area model
Authors: Hong Enyu , Ban Haibo , Qi Mingxu 
Published: August 2019

Abstract
The paper presents a design optimization method for a type of centrifugal compressor’s vaned diffuser with using a one-dimensional (1D) mathematical model to determine the best throat area ratio of the impeller to the diffuser. The research aims to verify of the 1D throat area mathematical model and to study the influence of vaned diffuser structure on the impeller-diffuser matching and the stage performance. The results of CFD analysis and experiments have proved that 1D throat area model can predict the throat area ratio of the impeller to the vaned diffuser accurately for the same choking mass flow at the required rotating speed. After optimization, the compressor performances and the matching between impeller and vane diffuser are considerably improved as well. The results and conclusions indicate that quick geometry modification of vaned diffusers can achieve excellent performance optimization and provide the theoretical basis for the selection of variable vaned diffusers.
Motion response analysis of mining vessel based on ANSYS/AQWA
Authors: Xu Hailiang , Neng Peng , Yang Fangqiong 
Published: August 2019

Abstract
To analyse the motion response of mining vessel under complex sea conditions and provide theoretical support for the design of heave compensation system, the hydrodynamic analysis software AQWA of three-dimensional potential flow theory was used to analyse the time-frequency response characteristics of mining vessel under the coupling of wind, wave and flow. The response amplitude operator (RAO) of the hull at different wave angles and the six-degree-of-freedom motion response of the hull at different currents were obtained. The results show that the wave angle has an influence on the Rao in the six degrees of freedom, but the frequency corresponding to the Rao peak is relatively close; the time domain analysis results show that the hull roll motion response is larger than the pitch; the maximum response angle of the roll is up to 4°; the effect of sea current velocity on swing, sway, and heave direction is different; the statistical average of wave force in different degrees of freedom is also affected by the wave angle. The simulation results in this paper can provide theoretical guidance for the design of multi-dimensional wave compensation system in mining system. Therefore, when designing wave compensation system, it is necessary to consider the influence of different situations.
Comparative Analysis of Hydrodynamic Performance of Propeller Under Different Turbulence Models
Authors: Zhou Xiaoming , Pan Huachen , Tian Xiaoqing , Zhu Zefei 
Published: August 2019

Abstract
In order to study the applicability of different turbulence models in the prediction of propeller hydrodynamic performance, computational fluid dynamics software CFX was used to simulate the thrust coefficient, torque coefficient and efficiency of VP1304 propeller under specific viscous flow field conditions by using k - ε models, k - ω models, SST models and RSM models respectively. The prediction results from the four turbulence models are compared with the experimental data of controlled pitch propeller VP1304 published by SVA Potsdam. It is concluded that the simulation prediction of performance due to the RSM model is the most accurate, Merits and demerits of RSM model is analyzed.
Analysis on Mechanical Properties of Single Conductor Considering Flexural Stiffness under Wind Load
Authors: Wang Xinxin , Zhao Jianpin , Zhao Puzhi , Zheng Yi , Yu Guoqing 
Published: August 2019

Abstract
In order to study the effect of flexural stiffness on the mechanical properties of single conductor under wind load, a configuration function of the conductor considering stiffness is established in this paper. Based on the configuration function, the finite element model is established, and the effects of suspension point angle, span on the mechanical properties of down lead conductor under wind load are studied. The results show that, compared with the catenary model, the model in this paper is more consistent with the experimental fitting formula. The angle of the suspension point has obvious influence on the tension of down lead conductor. With the increase of the angle of the suspension point from 0°to 80°, the tension decreases by nearly one third. The bending moment is affected by the alignment, and the reverse sign appears with the increase of suspension point angle. When the redundancy rate is the same, the span increases from 2 m to 4 m, and the tension of the conductor decreases by 18%.
Prediction of hydrodynamic characteristics of combined propellers based on CFD method
Authors: Su Shichuan , Wang Shengsen , Cao Jiabin , Feng Desheng 
Published: August 2019

Abstract
In recent years, with the concept of “green ship” put forward, it has been a major task for ship workers to improve ship propulsion efficiency and save fuel consumption. Combined propellers show higher propulsion efficiency and better energy saving effect, so they are favored by ship workers. This article using the computational fluid dynamics (CFD) software to the single propeller, tandem propellers and contra-rotating propellers was simulated in different speed coefficient, and forecast the propeller hydrodynamic performance, comparing single propeller, tandem propellers and contra-rotating propellers open water efficiency shows: the contra-rotating propellers and tandem propellers rear blade absorbing front blade axial velocity and trailing vortex energy, increase propeller thrust, to improve the efficiency of the propeller propulsion, energy conservation and emission reduction has important significance, also conforms to the concept of “green design” of the ship.
Temperature field modeling of the plate during hot rolling based on inverse heat conduction problem
Authors: Liu Wenhong , Guo Siying , Zhang Siyu 
Published: August 2019

Abstract
In the established temperature field model of plate hot rolling process, the heat transfer coefficients of each stage are solved by empirical formula, but due to the complexity of the production environment, temperature field models tend to be less accurate. In order to solve this problem, this paper designs a rolling experiment, collects the actual temperature data, and combines with genetic algorithm, simulated annealing algorithm and particle swarm optimization algorithm to correct the heat transfer coefficients of air-cooling zone, and the three algorithms are compared. Finally, the particle swarm algorithm is selected to establish the temperature field model of the hot rolling process. The average error of the final temperature field model calculation is within 14°C.
Vortex Shedding Mechanism of Post Cyclone-Bluff Body Stabilized Combustion
Authors: Wu Yunke , Li Zhiqiang , Zhang Zhihong , Liu Lifang , Wang Yuruo 
Published: August 2019

Abstract
V-gutter is one of the typical bluff bodies that often used for flame stabilization in the afterburning chamber of present turbine engine. For its small range of lean/rich fuel limits, weak anti disturbance capability and low combustion efficiency which may cause the flame in combustion chamber easily to be extinguished, the V-gutter still needs to improve performance. In this paper, a new method that adding a cyclone behind the bluff body to enhance the flame stabilization by the interaction of shedding vortex of bluffs body and this cyclone is proposed. Vortex shedding mechanism of the flow around V-gutter with post cyclone is studied. The numerical result shows that the post cyclone has an important impact on the vortex shedding mechanism of the flow around V-gutter. The flow resistance and fluctuation are reduced and the length of the recirculation zone is increased, which can lead to the improvement of the flame stabilization. On the contrary, the flow resistance and fluctuation increase, and the recirculation zone become shorter when the post cyclone source is outside, which is negative to the flame stabilization. The influence of the post cyclone diameter cannot be ignored either. The flow resistance is increased, the fluctuating characteristic is strengthened, the recirculation zone is shortened and the vortex shedding frequency is decreased when the cyclone diameter is increased.