bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the Flowfield Physics Within Compressible Turbulent Boundary Layers
Authors: Ferguson Frederick , Feng Dehua , Gao Yang 
Published: January 2020

Abstract
Predicting the velocity, the temperature and the heat transfer rates within compressible boundary layers remains a challenging problem. Under compressibility and high Reynolds conditions, the density variations become very significant, resulting in high heat transfer rates. The net result is an altering of the dynamics within the boundary layer that is significantly different from its laminar counterpart. Physical properties, such as the specific heat capacities, the viscosity and the thermal conductivity, which are often considered constant, now vary with respect to temperature, creating a strong coupling between the velocity and the temperature fields. Despite the progress made in this field of research, a common issue frequently expressed in the literature is the difficulty in acquiring high quality time-resolved velocity and temperature data in compressible flows, especially near the wall. The major objective of this study is to demonstrate the capabilities of the Integral-Differential Scheme (IDS) by solving the flow field challenges within compressible boundary layers. It was demonstrated that IDS have the capability of accurately solving the full Navier-Stokes equations under realistic conditions. In the case of the compressible boundary layer, the IDS capture the flow field physics. However, it was demonstrated that the IDS is highly sensitive to grid resolution as well as the prescribed boundary conditions.
Modified Nernst-Plank-Poisson Model for IPMC With Back-Relaxation Effects
Authors: Al-Allaq Aiman , Jaksic Nebojsa , Ansaf Bahaa , DePalma Jude , Duong Trung 
Published: January 2020

Abstract
The ionic polymer–metal composite (IPMC) is a new practical engineering material that, it has a wide range of capabilities in both dry and liquid environments. IPMC is a new candidate for diaphragms in micropump devices, micro and Nano robotic applications. IPMCs are regarded as a capable actuator for transportable applications, however, the unique combination of electrochemical and mechanical properties that they possess, such as back-relaxation, restraint their use in real-life applications. There have a lot of attempts to understand and model the IPMCs properties and build a whole prototype that can be used, with certainty, in different robotic, control, and medical applications, yet, till now, it seems that the dehydration and back-relaxation are still not modeled properly.
The Nernst-Plank-Poisson was chosen to be the base model for the IPMC behavior, we were able to create a new model that truly represent the back-relaxation effects that occur in IPMCs, we’ve called the new model as modified NPP model. The modification used captured data from our experimental work Our modified analytical NPP (Nernst-Plank-Poisson) model was the verified using MATLAB & Simulink, which showed that the model, and the controller design for it was able to first compensate the loss of position of the IPMC due to back-relaxation, and then track the desired position input signals with great accuracy. The model and designed controller can be utilized in verity of robotic applications.
Seamless Coupling of Peridynamics and Finite Element Method in Commercial Software of Finite Element to Solve Elasto-Dynamics Problems
Authors: Wang Xiaonan , Kulkarni Shank S. , Tabarraei Alireza 
Published: January 2020

Abstract
Peridynamics formulation provides a strong tool for modeling of crack propagation. Although its ability to handle crack propagation is impressive it suffers from the drawback of high computational cost. In order to reduce the computational cost, peridynamics can be coupled with the finite element method. In this approach, peridynamics is used in critical areas where crack growth can happen and finite element formulation is used everywhere else. We use an Arlequin based coupling method to couple both peridynamics and finite element domain and implement the coupling approach in an existing finite element package. Initially, the user meshes the whole domain using finite elements. The software converts finite element mesh in the critical areas into peridynamics points. The proposed approach automatically creates a seamless coupling between the two regions. An example of a bar hitting a fixed plate is solved and compared with pure finite element results to prove the robustness of the method. Also, a problem of crack propagation under mixed mode loading is solved.
CFD Study of Generation Process and Stability of a Fire Whirl in Large-Scale Fires
Authors: Satoh Koyu , Viegas Domingos , Pinto Claudia , Tu Ran 
Published: January 2020

Abstract
Large-scale urban and forest fires, especially earthquake-induced fires may produce huge fire whirls and cause serious damage, due to the involved tornado-like strong wind, together with radiation and swirling flame. If fire whirls are generated, the danger to firefighters increases extremely. Many small-scale experiments and CFD simulations on fire whirls have already been conducted and also our previous numerical studies examined the generation of a large fire whirl in an oil tank. However, details of large-scale fire whirls have not been clarified yet. In this study, developing the previous works, additional CFD simulations are conducted to examine the generation process and particularly the stability of fire whirls. Three schemes to generate fire whirls are employed, using the 15 × 15 PMMA fuel array in windy conditions and n-heptane burning in a steel pan placed centrally on the floor in a tall channel with staggered four corner gaps, also using a channel with a single corner gap. The numerical results showed that the relationship between the fire area and the wind blowing area is important on the fire whirl generation in the PMMA scheme and n-heptane fire burning scheme in a channel. In addition to the channel gap size to produce a maximum fire whirl, the effects of channel height and horizontal channel area upon the fire whirl are examined. The wall temperatures of the channel are important to keep the swirling motion stably, particularly the wall temperature at about 300°C can stabilize the fire whirl in a channel. Also multiple small fires placed surrounding the central swirling fire can increase the stability of the fire whirl, although too strong multiple fires may destroy the stability. These phenomena may be related to the real fire whirl generation in the natural environment.
Design and Control of a Variable Geometry Hybrid Wheel-Leg
Authors: Artates Jonivan , Bahr Behnam 
Published: January 2020

Abstract
Conventional wheeled platforms provide sufficient locomotion on smooth surfaces but are limited when contending with obstacles such as stairs, steep inclines, or rugged terrain. Legged robots, which are better suited in traversing such obstacles, require an increased number of actuators, and thereby expend more energy. This paper describes the Adaptive Wheel-Leg, AWL, that provides mobile robots with the benefits of both wheels and legs. AWL is a two degree-of-freedom, hybrid wheel-leg topology with instantaneous switching between modes. AWL provides two modes: 1) a single actuator rolling mode for smooth surfaces, and 2) a walking mode for rugged terrain. This paper presents the mechanism’s design and control methods. An experimental model and a simulation of an AWL equipped hexapod are also discussed.
An Investigation Into Structural-Induced Noise in an Electric Motor
Authors: Vuong Tung Xuan , Li Willow Yangliu , Al-Jumaily Ahmed , Pandey Neel 
Published: January 2020

Abstract
The paper presents an investigation into the noise generated by structural vibration of an electric motor used in appliance products using Computational Simulation Approach. In particular, a 3-D numerical simulation model is specifically developed to predict the frequency response of the stator under three different simulation conditions: radial force only, tangential force only and the combination of both forces. The obtained data is used to analyze the acoustic generation in the far-field. Experimental is used to validate the predicted results. It shows the predicted results are very close to experimental results.
Nuclear Fusion Detection Methods for Use With IEC Machines
Authors: Pasmann Sam , Farina Jordan , Dillon Heather 
Published: January 2020

Abstract
Despite the potential for limitless clean energy, nuclear fusion is seldom discussed in conjunction with other alternative energy sources. Nonetheless, there is a small but strong amateur community dedicated to the research of nuclear fusion. If grown, this community may help facilitate more conversation, interest, and eventual research into nuclear fusion.
An often-large barrier in independent fusion research is detection and quantification of reactions. This research outlines the common methods currently used for fusion detection in inertial electrostatic confinement (IEC) reactors and suggests an experiment to explore indirect methods of detection using Matlab code written for light emission analysis. Current indirect, or theoretical, methods of determining reaction rate are unreliable, as they do not consider all construction variables of the reactor. By measuring characteristics of the plasma to determine reaction rate, a more accurate indirect measurement method may be developed, allowing for a larger number of individuals to participate in nuclear fusion research.
Quantifying the Stiffness of Biceps Muscle Using Accelerometer
Authors: Salman Muhammad , Palmer Alan , Iqbal Sajid 
Published: January 2020

Abstract
With increasing awareness of health benefits from incorporating exercise for a more physically active lifestyle, a natural increase in injuries to connective tissues within the body is inevitable. Determining the condition of these tissues by current imaging techniques is expensive, difficult, and not entirely reliable. Using a Modally Hand Impact Hammer and 3D accelerometers, shear wave propagation from surface vibrations of superficial skeletal muscle was measured. The use of accelerometers in this technique contribute some advantages over other techniques. The ability to mount the accelerometers directly to subject area provides greater flexibility for the subject and the investigator. Utilizing this method provides low cost, non-invasive, reliable and repeatable measure of material characteristics. An increase in shear wave propagation and Modulus of Elasticity were observed in 10 subjects as the number of excited muscle fibers within the biceps brachii increased (muscular contraction) and decreased lower than initial resting values post muscular contraction. This technique may prove more practical in clinical settings for swift in-house or on-site assessments of muscle stiffness to help determine the condition. In a broader relationship, this process further demonstrates that techniques developed through mechanical engineering are beneficial to the health and biology fields.
Stabilizing Ship Motion With a Dual System Inertial Disk
Authors: Storaas Torstein R. , Virkesdal Kasper , S. Brekke Gitle , Rykkje Thorstein , Impelluso Thomas 
Published: January 2020

Abstract
Norwegian industries are constantly assessing new technologies and methods for more efficient and safer maintenance in the aqua cultural, renewable energy, and oil and gas industries. These Norwegian offshore industries share a common challenge: to install new equipment and transport personnel in a safe and controllable way between ships, farms and platforms. This paper deploys the Moving Frame Method (MFM) to analyze ship stability moderated by a dual gyroscopic inertial device. The MFM describes the dynamics of the system using modern mathematics. Lie group theory and Cartan’s moving frames are the foundation of this new approach to engineering dynamics. This, together with a restriction on the variation of the angular velocity used in Hamilton’s principle, enables an effective way of extracting the equations of motion. This project extends previous work. It accounts for the dual effect of two inertial disk devices, it accounts for the prescribed spin of the disks. It separates out the prescribed variables. This work displays the results in 3D on cell phones. It represents a prelude to testing in a wave tank.
Phenomenon of Fog Formation and Flow Characteristics of Droplet-Vapor-Gas Mixture in a Cooler-Condenser
Authors: Gu Hongfang , Guo Qiwei , Li Changsong , Zhou Qing 
Published: January 2020

Abstract
Fog formation occurs in the process of condensation in the presence of non-condensable gas if the bulk temperature is lower than its saturation temperature (supersaturated). The phenomena of fogging is the formation of small condensate particles mixing with the vapor/gas stream, which creates potential problems of the vapor/gas/condensate separation and environmental pollution. Therefore, understanding of fogging mechanism and prevention of fog droplet entrainment are one of technical concerns for design and operation of cooler-condensers in the process industry.
This paper presents the experimental study and numerical simulation of shell-side condensation with fog formation using a mixture of steam/non-condensable gas. The experimental data were collected on the two tube bundles (modified plastic tubes and stainless steel tubes). Using a high-speed photograph technique, the phenomenon of fog formation and flow characteristics of vapor/droplet transport were recorded over a wide range of test conditions. The numerical analysis of film and dropwise condensation, fog formation and droplet particle transport were simulated using different tube geometry and material, and flow velocity of air/droplet mixture. Based on simulation results, a new droplet trapping parameter is proposed to assess the optimal parameters of heat exchanger structural and operation conditions. Comparisons show that the numerical analysis results have a good agreement with experimental data and observations. These findings provide fundamental approach to account for the effect of fog formation, film and dropwise condensation, and droplet transport crossflow in cooler-condensers.
Dual Gyroscope Wave Energy Converter
Authors: Korsvik Håkon B. , Rognsvåg Even S. , Tomren Tore H. , Nyland Joakim F. , Impelluso Thomas J. 
Published: January 2020

Abstract
This research models the energy extracted by gyroscopic wave energy converters. The goal is to assess the use of such devices to provide supplementary power to fish farms and lighting on oilrigs. This project implements the Moving Frame Method (MFM) in dynamics to model the power generated from a gyroscopic wave energy converter. The MFM leverages Lie Group Theory, Cartan’s moving frames and a new notation from the discipline of geometrical physics. This research extends previous work by incorporating two inertial disks to counter the inducement of yaw, and it improves the numerical integration scheme. Furthermore, this work makes use of a coherent data structure founded in the Special Euclidean Group, and it defines the initial disk spin as a prescribed variable. It accounts for the prescribed variables by modifying the equations of motion. Finally, it conducts an analysis of the generator moments. After obtaining the suite of descriptive equations of motion, this project integrates them using the Runge-Kutta method. Finally, a simplified 3D simulation is made using the Web Graphics Library to improve the readers’ intuitive understanding of the device.
Modelling the Motion of a 2-Arm ROV
Authors: Saure Marius R. , Iversen Sondre H. , Snekkevik Andreas B. , Gebhardt Rose , Chen Zhiyang , Mignano Christopher , Luchtenburg Dirk , Impelluso Thomas J. 
Published: January 2020

Abstract
Norway conducts operations on a variety of structures in the North Sea; e.g. oilrigs, monopole windmills, subsea trees. These structures often require subsea installation, observation, and maintenance. A remotely operated vehicle (ROV) can assist in these operations. Automation of intended motion is the desired goal. This paper researches the motion of an ROV induced by the motion of the robotic manipulators, motor torques, and added mass of fluid. This project builds upon a previous project that had one robotic arm; this time, there are two, but the method is unchanged. Furthermore, this work explores both the patterns in addressing such challenges, and an improved integration scheme. This research uses the Moving Frame Method (MFM) to carry out this project. In fact, this paper demonstrates the ease with which the MFM is extensible. Notable is that this work represents an international collaboration between an engineering school in Norway and one in the US. This work invites further research into improved numerical methods, solid/fluid interaction and the design of Autonomous Underwater Vehicles (AUV). AUVs beckon an era of Artificial Intelligence when machines think, communicate and learn. Rapidly deployable software implementations will be essential to this task.
Evaluate the Mechanical and Thermal Behavioural Deformation of Auxetic Composite Nano-Carbon Fibers
Authors: Oudah E. Al-Harbi Mohammed , Saleh M. Almansour Mohammed , M. Alomair Yousef Ali , Nabat B. Altulohi Fahad , Osman M. , Alarifi Ibrahim M. 
Published: January 2020

Abstract
This study aims to identify the composition of the pyrolysis products obtained through pyrolysis in the structure of different auxetic designs. Two design specimens of auxetic nano-carbon fibers with different directional load were fabricated, solid carbon fibers and hexagonal auxetic carbon fibers. The deformation behavior is well-known and has been analyzed. 3D finite element (FE) models were used to investigate both structures. There was some impact on the specimens used, and the behavior of the strain and stress line was captured. The main purpose of the experiment was to define and test the auxetic structure’s use in industries that require nano-carbon fiber material that has excessively good mechanical and thermal properties. In order to prevent the deterioration of the properties caused by this phenomenon, sizing of the yarns and bundles was carried out. Moreover, to form a sizing coating on the elementary fibers, DMA tests have been conducted, and both the thermal and mechanical properties investigated. In this case, the sizing agent must be in a sufficiently softened state. The compositions can improve nano-carbon vs the adhesion of the polymer matrix for auxetic nano-carbon fibers, which allows the use of such fibers for the reinforcement of plastics without extra processing.
Patient-Specific Mitral Valve Replicas for Preoperative Planning of Mitral Valve Repair
Authors: Kruttschnitt Michael , Hassan Nouray N. , Tiemann Klaus , Hitschrich Niklas , Sodian Ralf , Lueth Tim C. 
Published: January 2020

Abstract
Mitral valve regurgitation is one of the most common heart valve disorders and mitral valve repair is the favored therapy. For preoperative planning of the procedure, heart surgeons mentally interpret ultrasound images of the mitral valve. To improve preoperative understanding of the mitral valve and preoperative planning of the repair, we and other groups research patient-specific mitral valve replicas. The mitral valve is segmented from 3D ultrasound image data of the heart and a corresponding casting mold is designed and 3D printed. With it, the mitral valve replica is cast out of silicone. So far, segmentation and casting mold design are done manually. This makes the manufacturing of the mitral valve replicas laborious and complicates clinical application. We present patient-specific mitral valve replicas where the segmentation is semi-automatic and the casting mold design is completely automatic. We use an existing software that semi-automatically segments mitral valves from 3D ultrasound image data and developed an automatic casting mold design that automatically creates casting molds based on the segmented mitral valves. With this, patient-specific mitral valve replicas can be manufactured that may help heart surgeons to get a more precise understanding of the mitral valve preoperatively and to plan the most effective surgical repair technique. The automation should facilitate independent and mass clinical application. We equipped a heart clinic with our system and manufactured patient-specific mitral valve replicas for several patients. A heart surgeon planned mitral valve repair with them. We present one of the cases.
Design of a High Speed Internal Gear Pump to Increase the Power Density of Electro Hydraulic Actuators (EHA) in Mobile Applications
Authors: Pietrzyk Tobias , Roth David , Jacobs Georg , Katharina Schmitz 
Published: January 2020

Abstract
Increasing the rotational speed of the internal gear pump entails addressing topics such as cavitation, overheating and filling problems of the tooth spaces. Besides the development of a tooth geometry and flow optimization, using CFD simulation is necessary. This paper discusses the design of the newly developed high speed internal gear pump. This includes a detailed description of the different parts as well as the dimensioning of the pump by using CFD simulations. The geometry of the pressure build-up groove has a significant effect of pressure build up inside the pump. Therefore, three different geometries are investigated. The calculation of the journal bearings for the internal gear as well as for the driving shaft is shown. To avoid cavitation problems, the suction pressure of the pump will be increased up to 25 bar. This paper will show the technical arrangements to reach this high suction pressure level whilst still using a radial shaft seal ring. In order to determine the efficiency of the newly developed high speed pump, a test rig was built up. The test rig allows the measurement of the volumetric efficiency as well as the hydraulic-mechanical efficiency at different operation points up to 10 000 rpm and 250 bar.
A Lightweight Framework of R-LATs for Large-Scale Application
Authors: Jia Kang , He Ruihua , Fu Gang , Su Wenjun , Liu Zhigang 
Published: January 2020

Abstract
Rotate laser automatic theodolite system (R-LATs) is a distributed larger volume metrology system. With considering its excellent parallel measurement capability and the adaptive expansion of measureable space, R-LATs has a good prospect in large scale application, e.g. as a space measurement solution for an entire factory room to fix the spatial coordinate measurement, AGV navigation, and large component alignment etc. However, in large application scenario, where multiple theodolites are adopted, the photosensors suffer heavy working load in distinguishing the theodolite of each fan laser. It seriously restricts the real-time character, raises the probability of wrong signal generation, and degrades the work performance of R-LATs distinctly. To overcome this bottleneck, this paper proposed a lightweight framework for R-LATs to lighten the work load of photosensor in distinguishing the theodolites. Firstly, the working principle of R-LATs and the visibility of theodolite were introduced. Then, the whole frame work of R-LATs was designed in three aspects to relieve the work load of photosensor, i.e. topological network construction for entire R-LAT, data structure design for both compute terminal and photosensor, and the dynamic schedule of the data process unit for entire R-LATs. At last, by simulating AVG navigation in a large scale application of R-LATs, the effectiveness of this paper was proofed by comparing the computational loads with traditional configuration.