Hasil untuk "Descriptive and experimental mechanics"

Michael A. Hernández Lamberty, Carla Nathaly Villacís Núñez, Ulrich Scheven et al.

Introduction Articular cartilage (AC) defects of the patellofemoral joint (PFJ) are clinically challenging and mechanically demanding. Osteochondral allograft (OCA) transplantation is the standard treatment for large cartilage injuries; however, little is known about intra-tissue mechanics after transplantation. Computational models suggest that cartilage thickness mismatch concentrates stresses at donor–recipient interfaces in OCA-treated patella, but direct experimental evidence is scarce. Local cartilage strain is closely linked to tissue health; therefore, the goal of this work was to provide a preliminary, full volume assessment of patellar cartilage mechanics before and after OCA transplantation. Methods A displacement-encoded MRI sequence was used to quantify full volume displacement and strain fields in human patellar AC before and after OCA transplantation under controlled indentation. Intact cadaveric patellae (n = 4) were prepared, with three serving as recipients and one as donor. Samples were cyclically compressed in a custom-built rig using nominal displacements of 1 and 2 mm. The complex phase data were unwrapped and converted to displacements; the Green–Lagrange strain tensor was computed using a finite element framework in FEniCS. Minimum principal strain ( Emin ) and maximum shear strain ( Emaxshear ) were analyzed. Donor–recipient step-off distance, representing cartilage-level geometric mismatch, was measured at the graft interface. Results Global displacement fields were similar between intact and OCA samples, with spherical indentation exhibiting through-thickness compression and lateral displacement in longitudinal and transverse directions. Emin localized beneath the indenter, while Emaxshear concentrated near the articular surface. OCA-transplanted samples exhibited localized changes in strain distribution near portions of the graft rim, though these features varied across samples. Top-view percentile maps highlighted redistributed high-strain regions in some OCA samples. Exploratory step-off plots showed sample-specific directional trends between geometric mismatch and donor-recipient strain differences, though these trends were not consistent across all samples. Discussion This exploratory study provides the first experimental full volume displacement and strain distributions of patellar cartilage after OCA transplantation. The localized strain variations observed after transplantation should be interpreted descriptively, given the single-donor design and sub-physiological loading. These results establish an experimental foundation for validating computational models of the donor-recipient cartilage interaction and geometric mismatch following OCA transplantation and work investigating OCA mechanics under physiological loading.

Tom Proulx

Lennart Linden, K. Kalina, J. Brummund et al.

In this contribution, we present a novel consistent dual-stage approach for the automated generation of hyperelastic constitutive models which only requires experimentally measurable data. To generate input data for our approach, an experiment with full-field measurement has to be conducted to gather testing force and corresponding displacement field of the sample. Then, in the first step of the dual-stage framework, a new finite strain Data-Driven Identification (DDI) formulation is applied. This method enables to identify tuples consisting of stresses and strains by only prescribing the applied boundary conditions and the measured displacement field. In the second step, the data set is used to calibrate a Physics-Augmented Neural Network (PANN), which fulfills all common conditions of hyperelasticity by construction and is very flexible at the same time. We demonstrate the applicability of our approach by several descriptive examples. Two-dimensional synthetic data are exemplarily generated in virtual experiments by using a reference constitutive model. The calibrated PANN is then applied in 3D Finite Element simulations. In addition, a real experiment including noisy data is mimicked.

J. M. Loor, Elisa Pérez Gracia, Jesús Conde Jiménez

Aim/Purpose: This study aims to design and validate an evaluation instrument for a didactic strategy based on gamification, specifically adapted to e-learning contexts in higher education. It addresses the ongoing challenge of enhancing student motivation, engagement, and retention in virtual learning environments. Background: With the sustained growth of online education, higher education institutions need to develop and evaluate coherent pedagogical strategies that promote active learning. Although gamification has shown the potential to increase student participation, there is a lack of validated instruments to measure its effectiveness. This study responds to that need by proposing a validated framework for evaluating a gamified instructional model. Methodology: A non-experimental, descriptive, cross-sectional design with a mixed-methods approach was used. The Delphi method was applied, involving 33 experts who evaluated the validity and reliability of the proposed strategy. Content validity was assessed using the Content Validity Coefficient (CVC), and reliability was confirmed through Cronbach’s alpha. Contribution: This study provides an empirically validated instrument for implementing and evaluating gamification-based strategies in e-learning environments. It offers a structured and reliable tool for enhancing instructional planning and student engagement in virtual settings. Findings: Experts showed high levels of agreement regarding the structure, clarity, and pedagogical coherence of the strategy’s components. The instrument demonstrated strong reliability and validity, confirming its suitability for evaluating gamified instructional models. The proposed framework is expected to inform future research and serve as a practical guide for educators integrating gamification into online learning. Recommendations for Practitioners: Educators and instructional designers should consider integrating gamification elements such as narratives, levels, and rewards to enhance student motivation and participation in e-learning environments. Recommendation for Researchers: Future research should explore the long-term effects of gamification on academic performance and assess its adaptability across different disciplines and educational levels. Impact on Society: The validated gamification strategy can improve online education accessibility and effectiveness, reduce dropout rates, and foster more engaging and interactive learning experiences. Future Research: Further studies should investigate how different game mechanics influence student engagement and learning outcomes in diverse cultural and academic settings.

Yota Abe, Aimi Tayama, Tomoki Iizuka et al.

<b>Background/Objectives:</b> This study aimed to provide preliminary normative data on intersegmental coordination patterns during heel rises at different knee joint positions and across various phases and periods. <b>Methods:</b> Twelve 21-year-old university students from the same cohort performed heel rises in knee-extended and knee-flexed conditions. Shank and foot kinematics were recorded using the VICON Oxford Foot Model, and intersegmental coordination was analyzed using a modified vector coding technique. <b>Results:</b> The results showed that coordination patterns varied significantly between the ascending and descending phases and across the early, middle, and late periods. In the early ascending phase, knee extension exhibited in-phase coordination (shank external rotation with hindfoot inversion), resembling propulsion-related coordination in gait, whereas knee flexion displayed greater anti-phase coordination between hindfoot plantar flexion and forefoot dorsiflexion. The middle and late periods demonstrated heel-rise-specific patterns, with coordination shifting from proximal to distal dominance. Knee flexion altered the coordination between the shank and hindfoot and between the hindfoot and forefoot in the sagittal plane compared to that during knee extension. <b>Conclusions:</b> These findings suggest that the knee position influences intersegmental coordination during heel rises, and the present results provide reference values that can enable future diagnostic validation and comparative studies in pathological populations.

Đorđe Brašanac, Marko Kapeleti, Igor Zlatović et al.

<b>Background:</b> Previous research has identified center of mass vertical oscillation and leg stiffness as the most common variables differentiating Natural and Groucho running techniques. The aim was to assess the inter-session reliability and inter-technique sensitivity of synchronized inertial measurement units and contact grids in quantifying kinematic and kinetic differences between Natural and Groucho running techniques. <b>Methods:</b> Eleven physically active and healthy males ran at a speed 50% higher than transition speed. Two sessions for Natural and two for Groucho running were performed, each lasting 1 min. <b>Results:</b> Most variables exhibited a similar inter-session reliability across running techniques, except contact time and center of mass vertical displacement, ranging from moderate to good (ICC = 0.538–0.897). A statistically significant difference between running techniques was found for all variables (<i>p</i> < 0.05), except for contact time and center of mass vertical oscillation (<i>p</i> > 0.05), likely due to inconsistency in reliability depending on the running technique, which may have covered the underlying differences. <b>Conclusions:</b> We can conclude that the combination of synchronized inertial measurement units and contact grids showed potentially acceptable reliability and sufficient sensitivity to recognize and differentiate between Natural and Groucho running techniques. The results may contribute to a broader understanding of the differences between these two running techniques and encourage the increased use of these devices within therapeutic, recreational, and sports running contexts.

Tri Hastiti Fiskawarni, E. Kurniawan, Andi Arie Andriani et al.

Physics learning in Indonesia is often experienced as abstract and disconnected from students’ daily cultural lives, which can weaken engagement and make key mechanics ideas harder to grasp. At the same time, many schools face the challenge of keeping local wisdom visible and meaningful within modern, standardized curricula. This study set out to identify physics concepts embedded in the traditional game congklak and to build a clear, classroom-ready mapping that links gameplay events to junior high school mechanics topics while also highlighting character values expressed through play. The research used a qualitative descriptive design with an ethnoscience perspective, combining a focused review of scholarly literature (2015–2025) with three recorded simulated congklak sessions (total 60 minutes) to document observable gameplay phenomena. Literature excerpts and observation logs were coded and synthesized through thematic analysis to develop an auditable concept–value framework. The results show that congklak repeatedly produces mechanics-relevant events that students can easily observe, such as short-range arc-like seed motion during placement, frequent contact interactions between seeds and the board that can be used to discuss interaction and momentum transfer qualitatively, and movement stopping that supports discussion of energy transfer and dissipation. The study also found that congklak naturally embeds local-wisdom values—patience, honesty in counting, fairness in turn-taking, cooperation, and strategic thinking—because these behaviors are required to play by the rules. The novelty of this work lies in providing a transparent workflow that bridges cultural practice and formal physics content while clearly treating gameplay observations as illustrative rather than experimental measurements. Overall, congklak offers a feasible, low-cost, and culturally meaningful way to contextualize introductory mechanics lessons and to open reflective conversations about values, contributing a replicable model for integrating local wisdom into science education.

Jorge Luis Mírez Tarrillo

The provision of food in pre-Inca/Inca cultures (1000 BC–≈1532 AD) in environments near Lake Titikaka (approximately 4000 m above sea level) was possible through an agricultural technique called “Waru-Waru”, which consists of filling the space (volume) between rows of land containing plants that are cultivated (a series of earth platforms surrounded by water canals) with water, using water as thermal energy storage to store energy during the day and to regulate the temperature of the soil and crop atmosphere at night. The problem is that these cultures left no evidence in written documents that have been preserved to this day indicating the mathematical models, the physics involved, and the experimental part they performed for the research, development, and innovation of the “Waru-Waru” technique. From a review of the existing literature, there is (1) bibliography that is devoted to descriptive research (about the geometry, dimensions, and shapes of the crop fields (and more based on archaeological remains that have survived to the present day) and (2) studies presenting complex mathematical models with many physical parameters measured only with recently developed instrumentation. The research objectives of this paper are as follows: (1) develop a mathematical model that uses finite differences in fluid mechanics, thermodynamics, and heat transfer to explain the experimental and theory principles of this pre-Inca/Inca technique; (2) the proposed mathematical model must be in accordance with the mathematical calculation tools available in pre-Inca/Inca cultures (yupana and quipu), which are mainly based on arithmetic operations such as addition, subtraction, and multiplication; (3) develop a mathematical model in a sequence of steps aimed at determining the best geometric form for thermal energy storage and plant cultivation and that has a simple design (easy to transmit between farmers); (4) consider the assumptions necessary for the development of the mathematical model from the point of view of research on the geometry of earth platforms and water channels and their implantation in each cultivation area; (5) transmit knowledge of the construction and maintenance of “Waru-Waru” agricultural technology to farmers who have cultivated these fields since pre-Hispanic times. The main conclusion is that, in the mathematical model developed, algebraic mathematical expressions based on addition and multiplication are obtained to predict and explain the evolution of soil and water temperatures in a specific crop field using crop field characterization parameters for which their values are experimentally determined in the crop area where a “Waru-Waru” is to be built. Therefore, the storage of thermal energy in water allows crops to survive nights with low temperatures, and indirectly, it allows the interpretation that the Inca culture possessed knowledge of mathematics (addition, subtraction, multiplication, finite differences, approximation methods, and the like), physics (fluids, thermodynamics, and heat transfer), and experimentation, with priority given to agricultural techniques (and in general, as observed in all archaeological evidence) that are in-depth, exact, practical, lasting, and easy to transmit. Understanding this sustainable energy storage technique can be useful in the current circumstances of global warming and climate change within the same growing areas and/or in similar climatic and environmental scenarios. This technique can help in reducing the use of fossil or traditional fuels and infrastructure (greenhouses) that generate heat, expanding the agricultural frontier.

Fariha Auliya Putri Prihardini

This study aims to determine the effectiveness of the digital platform Wakelet in improving students' analytical exposition writing performance by evaluating the overall improvement in students’ written work and identifying the writing component with the highest gain. The research employed a quantitative approach with a pre-experimental design involving one group of eleventh-grade students at a public senior high school in Surabaya. Students received treatment through the use of Wakelet as a writing learning medium, which facilitated the visual process of collecting, organizing, and structuring ideas. Data were obtained through pre-tests and post-tests and analyzed using descriptive statistics, paired sample t-tests, and effect size calculation. The results revealed a significant difference between the pre-test and post-test scores (p = 0.037) with a moderate effect size of 0.400. Among the five assessed components, students showed the greatest improvement in organization (1.96), followed by vocabulary (1.18), content (0.47), mechanics (0.09), and language use (0.04). These findings indicate that Wakelet can serve as an engaging and effective digital platform to help students develop critical thinking and more structured analytical exposition writing skills. Therefore, integrating Wakelet into English language teaching is considered beneficial in the EFL context.

Putu Santi Oktarina, Ni Wayan Satri Adnyani, Ni Luh Putu Gayatri

Writing is one of the most challenging language skills for learners of English as a Foreign Language, particularly at the secondary school level, where limited instructional time and large class sizes often hinder the provision of effective individualized feedback. This condition creates a need for alternative feedback strategies that are both efficient and pedagogically sound. This study aimed to analyze and compare the effectiveness of automated written corrective feedback based on artificial intelligence. The study employed a quantitative approach using a quasi-experimental non-equivalent control group pretest–posttest design. The participants consisted of 82 eighth-grade students divided into two intact classes, with 40 students assigned to the control group and 42 students to the experimental group. Data were collected through recount text writing tests administered as pretests and posttests, using an analytic scoring rubric covering content, organization, vocabulary, grammar, and mechanics. Data analysis was conducted using descriptive statistics and an independent samples t-test at a significance level of 0.05. The results indicated no statistically significant difference in recount text writing ability between students who received Automated Written Corrective Feedback and those who received teacher-provided Written Corrective Feedback. These findings suggest that both types of feedback are relatively equivalent in supporting the development of students’ writing skills. Overall, the study concludes that both AWCF and WCF can be flexibly implemented in writing instruction, with the implication that AI-based feedback technologies represent a viable alternative in contexts characterized by limited instructional resources.

Camilla Zilianti, Erfan Bashar, Anna Kyriakoudi et al.

Large animals are increasingly used as experimental models of respiratory diseases. Precise characterization of respiratory mechanics requires dedicated equipment with specific characteristics which are difficult to find together in the same commercial device. In this work, we describe building and validation of a computer-controlled ventilator able to perform rapid airways occlusions during constant flow inflations followed by a prolonged inspiratory hold. A constant airflow is provided by a high pressure source (5 atm) connected to the breathing circuit by three proportional valves. The combined action of three 2-way valves produces the phases of the breath. During non-inspiratory breath phases, airflow is diverted to a flowmeter for precise feedback regulation of the proportional valves. A computer interface enables the user to change the breathing pattern, trigger test breaths or run predetermined breaths sequences. A respiratory system model was used to test the ability of the ventilator to correctly estimate interrupter resistance. The ventilator was able to produce a wide range of constant flows (0.1–1.6 L/s) with the selected timing. Errors in the measurement of interrupter resistance were small (1 ± 5% of the reference value). The device described reliably estimated interrupter resistance and can be useful as a measuring tool in large animal research.

David W Middleton, Olivia Dolan

Abstract The accuracy of clinical communication in referrals to dermatology has not been fully explored. Baseline analysis of inpatient ward referral to a dermatology service revealed that only 37% of referrals used accurate descriptive terminology. Theme analysis of individual descriptive terms used was performed to assess knowledge deficits and develop a novel intervention to improve descriptive accuracy. A descriptive algorithm was developed to act as a scaffolding resource for the use of descriptive terms. The Belfast Dermatology Descriptive Algorithm was developed as a tool to determine primary and secondary morphological features of eruptions, and to highlight common clinical pitfalls. It was designed to adhere to principles of adult learning. Assessment was completed following the introduction of the algorithm. The accuracy of descriptions used was increased to 70% with the introduction of the resource. This outcome reflects how educational interventions, in the format of an accessible resource tool, can be used as a unique intervention to improve education in clinical practice.

Koji Hasegawa, Yuya Kishimoto

The interfacial instability of a complex fluid in a multiphase flow system is ubiquitous in both nature and industry. We experimentally investigated the spreading and interfacial instability dynamics of a binary droplet (a water and 2-propanol (IPA) mixture) on an immiscible (sunflower oil) pool. For droplets of 40 wt% IPA solution on sunflower oil, fingering instability occurred at the spreading liquid front. To reveal the interfacial characteristics of the spreading and fingering processes, we analyzed the interplay among the speed, diameter, and number of fingers on the spreading front. Based on our observations, the finger length, wavelength between the fingers, head length, and neck length were quantified. Our experimental results clearly demonstrate that fingering instability can be driven by the capillary effect for a liquid–liquid system as well as the Plateau–Rayleigh instability. We hope that our results will inspire further experimental and numerical investigations to provide deeper insights into the interfacial dynamics of multicomponent droplets in a liquid pool.

Hannah R. Freeman, Harish Chander, Sachini N. K. Kodithuwakku Arachchige et al.

Background: Taking inspiration from the classical 1974, “moving room experiment” by Lee and Aronson, a “virtual moving room paradigm (Vroom)” was designed using virtual reality (VR) to assess postural control behavior. Methods: Thirty healthy adults (age: 21 ± 1 years; height: 166.5 ± 7.3 cm; mass: 71.7 ± 16.2 kg) were tested for postural stability in a virtual moving room paradigm (Vroom). The Vroom consisted of randomized virtual and visual perturbations of the virtual room moving toward and away from the individual, during both unexpected and expected trials. Objective postural sway variables and subjective experiences to VR using the simulator sickness questionnaire as well as balance confidence scale were also assessed and analyzed using a two way (2 × 2 [2 moving room direction (Toward vs. Away) and 2 knowledge of moving room (unexpected vs. expected)] repeated measures analysis of variance (ANOVA), and a one-way repeated measures ANOVA and paired sample <i>t</i>-test, respectively at an alpha level of 0.05. Results: Significantly greater postural sway was observed when the virtual room moved toward the participant than when moving away, and when it moved unexpectedly, compared with the expected moving room. Significantly improved balance confidence with realistic immersion and without simulator sickness was also observed. Conclusions: Our findings provide evidence indicating that the virtual moving room induces postural perturbations that challenge the postural control system, especially when the moving room is unexpected and moves toward the individual. Additionally, increased balance confidence and realistic immersion in the virtual environment with no adverse effects of simulator sickness were observed, providing evidence for the beneficial effects of the Vroom. Thus, the Vroom can be an easy and cost-effective method to expose individuals to realistic, virtual, and visual perturbations that challenge the postural control system and increase balance confidence, with realistic immersion and without adverse effects.

Yupeng Sun, Hafiz Muhammad Adeel Hassan, Joe Alexandersen

Stacked plate heat exchangers are widely used in thermal energy storage systems and a comprehensive and accurate analysis is necessary for their application and optimization. The fluid flow distribution between the plates is important to ensure even and full usage of the thermal energy storage potential. However, due to the complex topography of the plate surface, it would be computationally expensive to simulate the flow distribution in the multiple channels using a full three-dimensional model, so this work applies a reduced-dimensional model to significantly reduce the computational cost of the simulation and provides a comprehensive analysis of the effect of the internal structure on the internal flow distribution. The work extends a previously presented model to consider transient flow and a multichannel height distribution strategy to allow for simulating multiple channels between stacks of plates. Based on fully-developed flow assumptions, the three-dimensional model is reduced to a planar model, thus obtaining simulation results with satisfactory accuracy at a significantly lower computational cost. The model is verified by a three-dimensional simulation of a sliced two-channel model representing the considered system. The reduced-dimensional model gives similar results to the three-dimensional model for different geometrical and physical parameters. Lastly, the extended reduced-dimensional model is used to simulate the flow of a full two-channel model and the influence of the plate topography on the internal flow distribution is investigated through a comprehensive parametric analysis. The analysis shows that the complex topography of the plate surface eliminates the variation in inlet velocity and significantly changes the internal fluid flow, eventually resulting in a consistent velocity distribution.

Nguyen Thai Chung, Duong Thi Ngoc Thu

This paper presents some results on the linear stability research of Stiffened Functionally Graded Carbon NanoTube-Reinforced Composite (SFG-CNTRC) plates under static in-plane loads by the Finite Element Method (FEM) and a new four-variable refined plate theory. The governing equations for the static buckling of the system are obtained by the new four-variable refined plate theory and FEM. The eigenvalue problem method was used to solve the equation to determine the critical force of the plates. A numerical example is compared with the results in another research to check the validity of the present algorithm. The influences of some factors such as plate theory, CNT distribution along the layer thickness, stiffener height ratio, and fiber orientation angle on the critical buckling loads and unstable regions are discussed.

Simone Siriano, Néstor Balcázar, Alessandro Tassone et al.

The breeding blanket is one of the fundamental components of a nuclear fusion reactor and is responsible for the fuel production, generating tritium through neutronic capture reaction between lithium and neutrons. Lithium is a liquid PbLi alloy and the helium formed as reaction by-product can coalesce into bubbles, generating a two-phase mixture with a high-density ratio (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>η</mi><mi>ρ</mi></msub><mo>∼</mo><msup><mi mathvariant="script">O</mi><mn>5</mn></msup></mrow></semantics></math></inline-formula>). These bubbles can accumulate and stagnate within the blanket channels with potentially harmful consequences. In this work, the interIsoFoam solver of OpenFOAM v2012 is used to simulate bubble motion for a two-phase mixture representative of the He-PbLi system to test its potential for future developments in the field of fusion. In a first phase, several traditional benchmarks were carried out, both 2D and 3D, and considering the two variants of the VOF method implemented in the solver, isoAdvector and plicRDF. Subsequently, He bubbles of different diameters rising in liquid PbLi (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>η</mi><mi>ρ</mi></msub><mo>=</mo><mn>1.2</mn><mo>×</mo><msup><mn>10</mn><mn>5</mn></msup></mrow></semantics></math></inline-formula>) were analysed to investigate different regimes. For a Eötvös number (Eo) greater than 10, it was possible to recreate the axisymmetric, skirted, oscillatory regimes and the peripheral and central breakup regimes. For Eo < 10, non-physical deformations of the interface are observed, probably generated by spurious velocities that have a greater impact on the solution for very small bubbles and rising velocities.

Minh Khai Le Thieu, H. Haugen, J. Sanz‐Esporrin et al.

OBJECTIVES To evaluate new lateral bone formation and lateral volume augmentation by guided bone regeneration (GBR) in chronic non-contained bone defects with the use of a non-resorbable TiO2 -block. MATERIALS AND METHODS Three buccal bone defects were created in each hemimandible of eight beagle dogs and allowed to heal for eight weeks before treatment by GBR. Each hemimandible was randomly allocated to 4 or 12-week healing time after GBR and three intervention groups were assigned by block randomization: TiO2 block: TiO2 -scaffold and a collagen membrane, DBBM particles: Deproteinized bovine bone mineral (DBBM) and a collagen membrane, Empty control: Collagen membrane only. Microcomputed tomography (microCT) was used to measure the lateral bone formation and width augmentation. Histological outcomes included descriptive analysis and histomorphometric measurements. RESULTS MicroCT analysis demonstrated increasing new bone formation from four to twelve weeks of healing. The greatest width of mineralized bone was seen in the empty controls, and the largest lateral volume augmentation was observed in the TiO2 block sites. The DBBM particles demonstrated more mineralized bone in the grafted area than the TiO2 blocks, but small amounts and less than the empty control sites. CONCLUSION The TiO2 blocks rendered the largest lateral volume augmentation but also less new bone formation compared to the DBBM particles. The most new lateral bone formation outward from the bone defect margins was observed in the empty controls, indicating that the presence of either graft material leads to slow appositional bone growth.

Mehdi Mostafaiyan, Sven Wießner, Gert Heinrich et al.

We introduce an improved conservative direct re-initialization (ICDR) method (for two-phase flow problems) as a new and efficient geometrical re-distancing scheme. The ICDR technique takes advantage of two mass-conserving and fast re-distancing schemes, as well as a global mass correction concept to reduce the extent of the mass loss/gain in two- and three-dimensional (2D and 3D) problems. We examine the ICDR method, at the first step, with two 2D benchmarks: the notched cylinder and the swirling flow vortex problems. To do so, we (for the first time) extensively analyze the dependency of the regenerated interface quality on both time-step and element sizes. Then, we quantitatively assess the results by employing a defined norm value, which evaluates the deviation from the exact solution. We also present a visual assessment by graphical demonstration of original and regenerated interfaces. In the next step, we investigate the performance of the ICDR in three-dimensional (3D) problems. For this purpose, we simulate drop deformation in a simple shear flow field. We describe our reason for this choice and show that, by employing the ICDR scheme, the results of our analysis comply with the existing numerical and experimental data in the literature.

Paul McGinn, Daniel Pearce, Yannis Hardalupas et al.

This paper provides new physical insight into the coupling between flow dynamics and cavitation bubble cloud behaviour at conditions relevant to both cavitation inception and the more complex phenomenon of flow “choking” using a multiphase compressible framework. Understanding the cavitation bubble cloud process and the parameters that determine its break-off frequency is important for control of phenomena such as structure vibration and erosion. Initially, the role of the pressure waves in the flow development is investigated. We highlight the differences between “physical” and “artificial” numerical waves by comparing cases with different boundary and differencing schemes. We analyse in detail the prediction of the coupling of flow and cavitation dynamics in a micro-channel 20 μm high containing Diesel at pressure differences 7 MPa and 8.5 MPa, corresponding to cavitation inception and "choking" conditions respectively. The results have a very good agreement with experimental data and demonstrate that pressure wave dynamics, rather than the “re-entrant jet dynamics” suggested by previous studies, determine the characteristics of the bubble cloud dynamics under “choking” conditions.