Microgravity Science and Technology最新文献

{"title":"Model-Based Investigation of a Dielectrophoretic Microfluidic Device for the Separation of Polystyrene Particles","authors":"Wenbo Han,&nbsp;Hongyuan Zou,&nbsp;Yiwen Zheng,&nbsp;Yu Liu,&nbsp;Xin Wang,&nbsp;Wei Li,&nbsp;Yuqing Sun,&nbsp;Hongpeng Zhang","doi":"10.1007/s12217-024-10150-8","DOIUrl":"10.1007/s12217-024-10150-8","url":null,"abstract":"<div><p>Particle separation holds great significance as it has the potential to enhance product quality, efficiency, and safety across various industries by selectively sorting particles based on their specific characteristics. This, in turn, contributes to the improvement of processes in areas such as product manufacturing, environmental protection, and resource extraction. This paper proposes a novel microfluidic platform employing dielectrophoresis (DEP) principles to achieve the sorting of particles based on their size. This methodology leverages the dielectric characteristics of polystyrene particles. By manipulating various control parameters, such as electrode shapes (planar, V-shaped, and sinusoidal), the alteration of angles within the same electrode shape, adjustments in electrode widths, and electrode quantity. The study utilizes numerical simulation to compute the spatial distribution of the electric field within the microfluidic chip and predict the trajectories of particles within the microfluidic channel. Through quantitative comparison and analysis, a more optimized microfluidic chip with smaller size and shorter time, capable of effectively separating particles, is ultimately presented.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on Dynamic Properties and Heat Transfer Mechanism of Droplet Impact on the Heated Wall Under a Leidenfrost State","authors":"Lu Liu,&nbsp;Yitie Sun,&nbsp;Tai Wang,&nbsp;Shengrui Li,&nbsp;Run Yan,&nbsp;Teng Wang,&nbsp;Xinyu Dong","doi":"10.1007/s12217-024-10153-5","DOIUrl":"10.1007/s12217-024-10153-5","url":null,"abstract":"<div><p>In order to explore the dynamic properties and heat transfer mechanism of droplet impact on the heated wall, this study employs numerical simulation to analyze the Leidenfrost phenomenon caused by droplet impact. The occurrence mechanism of Leidenfrost phenomenon is analyzed from various perspectives, including droplet morphology, gas film formation, and interaction with the heated wall. The study reveals that the droplet, gas film, and heated surface mutually influence each other. As the droplet evaporates, water vapor is produced, and the gas film prevents direct contact between the droplet and the heated wall, resulting in the Leidenfrost phenomenon. The effects of droplet impact velocity, droplet size, and wall temperature on the Leidenfrost phenomenon were further investigated. The results indicate that a higher droplet impact velocity results in increased kinetic energy and a higher spreading coefficient, leading to enhanced heat exchange ability. However, the time taken to reach the maximum spreading coefficient differs from that of non-phase-change droplets. Additionally, smaller droplet sizes exhibit a more significant effect of surface tension on maintaining droplet shape. This results in a shorter spreading time for the droplet, but also higher kinetic energy consumption and a relatively smaller spreading coefficient. For the heat flow density, the larger impact velocity and size of droplet can increase the heat flow density and improve heat transfer. An increase in wall temperature significantly increases the heat flow density and is a crucial factor in sustaining the droplet Leidenfrost phenomenon.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Gravity Modulation on a Stability of Plane-Parallel Convective Flow in a Vertical Fluid Layer with Heat Sources","authors":"T. P. Lyubimova,&nbsp;E. O. Lobova","doi":"10.1007/s12217-024-10151-7","DOIUrl":"10.1007/s12217-024-10151-7","url":null,"abstract":"<div><p>This paper is devoted to the investigation of the stability of plane-parallel flow in a vertical fluid layer with uniformly distributed heat sources in modulated gravity field. The layer boundaries are rigid and maintained at equal constant temperatures. Gravity is assumed to be vertical and consisting of both mean and sinusoidal modulation (‘jitter’). Specific feature of this problem is that in the absence of modulation, at zero Prandtl number, the decrements of normal-mode perturbations of the base state are complex-valued and hydrodynamic instability mode is caused by travelling perturbations (travelling vortices at the boundaries of counter flows). With the increase in Prandtl number the instability mode changes from hydrodynamic instability of the counter flows to growing thermal waves. In the presence of gravity modulation, the base flow is the superposition of the same stationary flow as in the absence of modulation and time-periodic flow. The linear stability of this base state is studied by the numerical solution of the linearized equations of small perturbations. Numerical data on temporal evolution of perturbations are used to determine the decrements of perturbations and instability boundaries at different values of the Prandtl number. The calculations confirm that all perturbations are quasi-periodic. Parameter ranges where modulation makes stabilizing or destabilizing effect are defined. Sharp stabilization of the base flow in low-frequency range is discovered and explained by transformation of the neutral curves with the decrease of frequency which incleds formation of a bottleneck, break into two instability regions (the isolated region of hydrodynamic instability at lower Grashof number values and bag-shaped region of thermal wave instability at higher Gr), decrease in the size of the hydrodynamic instability region and shift upward of the thermal wave instability region and vanishing the isolated region of hydrodynamic instability.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical and Constitutive Analysis of Granular Column Collapse Experiments Under Reduced-Gravity Conditions","authors":"Sen Yang,&nbsp;Xiaohui Cheng,&nbsp;Meiying Hou","doi":"10.1007/s12217-024-10145-5","DOIUrl":"10.1007/s12217-024-10145-5","url":null,"abstract":"<div><p>The research on granular column collapse under various gravity levels is of great significance for the study of granular rheology and its applications in reduced-gravity space engineering. We firstly reviewed a rare experimental investigation that observed a gravity-related run-out distance of the granular column collapse in this paper. To identify the origin of the gravity-related run-out distance, a unified constitutive model was used to simulate the behavior of granular materials in these experiments based on a large deformation numerical method, the smoothed particle hydrodynamics (SPH). The parameters of this constitutive model were also discussed. Numerical simulations can reproduce the run-out distances that positively correlate with the gravity level, above 0.03 g in particular. Based on the numerical and constitutive analysis, this gravity-related runout distance is attributed to the combined influence of gravity-induced pressure and shear strain rate levels on granular flow.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Experimental Characterization of Capillary Driven Flows in Microgravity","authors":"Domenico Fiorini,&nbsp;Alessia Simonini,&nbsp;Johan Steelant,&nbsp;David Seveno,&nbsp;Miguel Alfonso Mendez","doi":"10.1007/s12217-024-10142-8","DOIUrl":"10.1007/s12217-024-10142-8","url":null,"abstract":"<div><p>This work investigates the capillary rise dynamics of highly wetting liquids in a divergent U-tube in the microgravity conditions provided by 78th European Space Agency (ESA) parabolic flight. This configuration produces a capillary-driven channel flow. We use image recording in backlight illumination to characterize the interface dynamics and dynamic contact angle of HFE7200 and Di-Propylene Glycol (DPG). For the case of HF7200, we complement the interface measurements with Particle Tracking Velocimetry (PTV) to characterize the velocity fields underneath the moving meniscus. In the DPG experiments, varying liquid column heights are observed, with a notable decrease in meniscus curvature when the contact line transitions from a pre-wetted to a dry substrate. In contrast, for HFE7200, the interface consistently advances over a pre-wetted surface. Despite this, a reduction in meniscus curvature is detected, attributed to inertial effects within the underlying accelerating flow. PTV measurements reveal that the region where the velocity profile adapts to the meniscus velocity decreases as interface acceleration increases, suggesting a direct relationship between acceleration and the velocity adaptation length scale.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the Applicability of the Boer Formula for Estimating the Angular Velocity of Rotation Of a Small Spacecraft by Measuring the Components of The Induction Vector of the Earth's Magnetic Field in Evaluating Micro-Accelerations and Forming Control Laws","authors":"Andry Sedelnikov,&nbsp;Roman Skidanov,&nbsp;Anastasia Taneeva,&nbsp;Luisa Manukyan,&nbsp;Maksim Ivanushkin,&nbsp;Marsel Mordanov","doi":"10.1007/s12217-024-10148-2","DOIUrl":"10.1007/s12217-024-10148-2","url":null,"abstract":"<div><p>The paper presents studies on the correctness of the application of the simplified Boer formula for estimating the components of the angular velocity vector of the spacecraft using the example of the small ISOI spacecraft (SXC3-219). The simplification consists in neglecting the total derivative of the induction vector of the Earth's magnetic field in time compared to the local derivative. This is due to the fact that measurements are carried out quite often. Therefore, the magnetic induction vector in two adjacent dimensions can be considered unchanged. The aim of the work is to estimate the error in determining the angular velocity due to this simplification. The presented results show the admissibility of neglecting the full derivative, provided that the measurement frequency is sufficient. Reference metrological tests were carried out, in which a gyroscopic angular velocity vector meter was selected as the reference measuring instrument. The errors in the estimates of micro-accelerations and the control moment, which are a consequence of the error in determining the angular velocity, are calculated.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Average Deformation of Sessile Drop Under High Frequency Vibrations","authors":"Andrey Ivantsov,&nbsp;Tatyana Lyubimova","doi":"10.1007/s12217-024-10146-4","DOIUrl":"10.1007/s12217-024-10146-4","url":null,"abstract":"<div><p>The behavior of a liquid drop placed on an oscillating solid substrate is studied. The vibrations are normal to the plane of the substrate. The amplitude of the vibrations is assumed to be small compared to the radius of the drop, and the vibration frequency is suppose to be much larger than the frequencies of the natural oscillations of the drop shape. The effect of vibrations on the drop shape is studied for a small values of the vibration parameter equal to the ratio of the vibration pressure to the capillary pressure. It is assumed that the drop surface in the absence of vibrations is hemispherical. Under the influence of vibrations, the drop height decreases and the base area increases. In this case, the surface deformation changes proportionally to the vibration parameter. At finite values of the vibration parameter, the quasi-equilibrium shape can differ significantly from spherical. In this case, the problem for pulsations is solved numerically using the boundary element method. To determine the average shape of a drop at finite values of the vibration parameter, the variational principle is used. The obtained results are in good agreement with the solution in the limit of small values of the vibration parameter. With an increase in the vibration parameter, the average contact angle decreases, the area of the base area increases, and the height decreases.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability Analysis of Mixed Convection of Nanofluid Flow Through a Horizontal Porous Channel Using LTNE Model","authors":"Harsha S V,&nbsp;Chandra Shekara G,&nbsp;Hemanth Kumar C,&nbsp;Mayur D H","doi":"10.1007/s12217-024-10140-w","DOIUrl":"10.1007/s12217-024-10140-w","url":null,"abstract":"<div><p>The present article investigates the stability of the mixed convective flow of nanofluids through a horizontal porous channel under the influence of a constant pressure gradient, utilizing the local thermal nonequilibrium (LTNE) model. The governing equations are derived by integrating the Oberbeck-Boussinesq theory with the Darcy model for low-permeability porous media. Using linear stability theory, we formulate a generalized eigenvalue problem (GEP) in terms of non-dimensional parameters. The weighted residual Galerkin method (WRGM) is then employed to solve the GEP, and the results are compared analytically. The findings of this study reveal that a horizontal pressure gradient initiates convection in an oscillatory mode rather than a stationary one. We identify that the interphase scaled heat transfer coefficient, thermal diffusivity ratio, nanoparticle volume fraction, and horizontal pressure gradient collectively influence the onset of oscillatory convection. Notably, our investigation into Titanium Oxide (TiO₂), Copper Oxide (CuO), and Aluminum Oxide (Al₂O₃) nanoparticles reveals that TiO₂ particles enhance the onset of convection compared to Al₂O₃ and CuO, while CuO nanoparticles exhibit greater thermal stability. Further, the nonlinear stability analysis is performed using the method of lines in conjunction with regularization and finite difference schemes for spatial derivatives. The time evolution of all field variables is simulated through the visualization of streamlines and isotherms, providing a detailed representation of the system's dynamics. Additionally, the critical values of the Darcy-Rayleigh number are computed and compared for both linear and nonlinear stability analyses. The results demonstrate the equivalence of linear instability and nonlinear stability boundaries in the absence of a constant pressure gradient, whereas subcritical instability becomes apparent in its presence. These insights advance our understanding of mixed convective flows in porous media, with potential implications for various engineering and environmental applications.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Ternary Phase-Field Model for Separation of Water from a Water/Oil Mixed Drop Using Lamb Waves","authors":"Zhijie Zhang,&nbsp;Zichen Wang,&nbsp;Zhaodong Yang,&nbsp;Yang Wang,&nbsp;Wei Liang","doi":"10.1007/s12217-024-10144-6","DOIUrl":"10.1007/s12217-024-10144-6","url":null,"abstract":"<div><p>In this work, we propose a ternary phase-field model for separation of water from a water/oil mixed drop using Lamb waves. In this model, we describe a Cahn–Hilliard/Navier–Stokes model for the simulation of incompressible flows composed of three immiscible components, where surface tension, gravity, and the acoustic streaming force of Lamb waves act on a water/oil mixed drop are taken into account through volumic forces. To test the present model, we further conduct separation experiments of oil–water mixtures driven by surface acoustic waves on a non-piezoelectric substrate. The numerical results are in good agreement with the experimental solutions illustrate that present model has the good capability in the study of the separation of water from a water/oil mixed drop using Lamb waves.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relative Trajectories of Contaminated, Spherical Drops in a Temperature Gradient and Gravity at Finite Stokes Numbers","authors":"Michael Rother","doi":"10.1007/s12217-024-10141-9","DOIUrl":"10.1007/s12217-024-10141-9","url":null,"abstract":"<div><p>This work is a theoretical investigation into the effect of finite droplet inertia on combined gravitational and thermocapillary interactions of spherical drops covered with an incompressible surfactant film. The significance of droplet inertia is indicated by the magnitude of the Stokes number <b><i>St</i></b>. Initial calculations are a continuation of previous results from <b><i>St</i></b> = 0 to finite Stokes numbers at <span>(varvec{O(1)})</span> drop-to-medium viscosity and thermal conductivity ratios. Interesting outcomes, such as stable tandem motion and complex relative trajectories, are observed. At more realistic <span>(varvec{O(10)})</span> ratios, the results tend to be dampened from those at lower values, although unusual behavior still occurs. Finally, interactions are determined for two physical systems, water drops in air and mercury drops in <b><i>n</i></b>-pentane. At normal gravity, two limits are usually possible. In order for the thermocapillary and gravitational contributions to be equal, the drops and their corresponding Stokes numbers must be small, while for larger drops at higher <b><i>St</i></b>, gravity is the dominant driving force. For water droplets in air with radii less than 10 <span>(varvec{mu })</span>m, van der Waals forces control the interactions. However, drop inertia is the most important factor for droplets with radii greater than 25 <span>(varvec{mu })</span>m. Even a small thermocapillary effect can have noticeable consequences on the relative trajectories for intermediate-sized drops. Some comments are made on the difficulty in experimentally reproducing the theoretical results, with a recommendation of centi- or milligravity conditions.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"36 5","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}