The dynamics of an incompressible fluid drop under the action of non-uniform electric field are considered. The drop is bounded axially by two parallel solid planes, which in the examined case are considered to be heterogeneous. The external electric field acts as an external force which causes motion of the contact line. In equilibrium, the drop has the form of a circular cylinder. The equilibrium

A large amount of heat can be dissipated more efficiently by utilizing the latent heat than the sensible heat of coolant using condensation technique. In addition, cooling by microchannel is found as a promising method to dissipate more heat than the conventional channel. The application of condensation in a microchannel under different gravity conditions becomes very important due to rising demand

In this paper, we investigate experimentally and numerically the dynamics of the drainage of a transparent capillary tube (radius 0.4 mm). A non-wetting fluid (gas) displaces a wetting fluid (oil). The gas phase is continuously injected at an extremity of the capillary tube (inlet section) at a constant injection-rate \(Q_{inj}\), ranging from 0.1 to 10 ml/h, corresponding to capillary numbers Ca varying

The surface tension of liquids at high temperatures is generally measured with the well-established oscillating drop method in a contactless environment. However, technical difficulties in surface tension measurements make it hard to apply the oscillating drop method to the aerodynamic levitation (ADL) system, the most reliable levitation technique for liquids with low electrical conductivity. In this

Systems of solid particles in suspension driven by a time-periodic flow tend to create structures in the carrier fluid that are reminiscent of highly regular geometrical items. Within such a line of inquiry, the present study provides numerical results in support of the space experiments JEREMI (Japanese and European Research Experiment on Marangoni flow Instabilities) planned for execution onboard

Nowadays the two-phase closed thermosyphon (TPCT) has been widely used as an important heat transfer medium for passive cooling systems. Since the enhancement of the performance of electronic device releases a considerable amount of heat, the development of working fluids which can improve thermal performance of the TPCT is necessary. In this experiment, two different type of MWCNT nanofluids were

Muscle atrophy occurs in human musculature system due to inactivity of muscles in microgravity environment. Herein, a novel designed countermeasure gravitational load modulation bodygear is developed to enhance muscle activity. The bodygear is devised to compress the body through axial loading from shoulder to feet. The time and frequency domain parameters of electromyography (EMG) signals showed that

Two series of flow boiling experiments have been conducted onboard the International Space Station (ISS) as a part of the TPF (Two-Phase Flow) experiment promoted by JAXA during July 2017–March 2018, February 2019–July 2019. Microgravity data on two-phase flow and heat transfer in flow boiling of n-Perfluorohexane (FC-72) have been obtained by a copper heated test tube and a transparent glass heated

For the present study numerical simulations of subcooled flow boiling of FC-72 in microgravity have been conducted to accompany boiling experiments performed in microgravity on the International Space Station (ISS). The numerical domain represents the geometry of the experimental test cell. For all simulations the open source framework OpenFOAM was employed, including extensions to the interFoam solver

Ground-based freefall facilities are to create microgravity environment on earth for studying the space-related or fundamental sciences, which have been widely used in the field of combustion, fluid, physics and material sciences. Aiming to serve for the broader microgravity science and preliminary tests for projects onboard the upcoming assembly of Chinese Space Station, a 2.2 second freefall facility

Mankind is setting to colonize space, for which the manufacturing of habitats, tools, spare parts and other infrastructure is required. Commercial manufacturing processes are already well engineered under standard conditions on Earth, which means under Earth’s gravity and atmosphere. Based on the literature review, additive manufacturing under lunar and other space gravitational conditions have only

The work is devoted to the investigation of the peculiarities of the formation, dynamics and coalescence of vapor–gas bubbles as a result of continuous ultrasonic (US) exposure to a liquids containing anionic surfactant of various concentrations. It is found that large bubbles of millimeter size which are formed in pure water due to coalescence processes, freely rise to the surface. With time, the

This paper presents the results of the thermocapillary motion of a spherical droplet under Marangoni flow conditions, which takes place in a zero-gravity environment where buoyancy effects become insignificant. In such an environment the droplet moves from the cold region to the warm region due to the variation of surface tension induced by the temperature gradient. This two-phase flow problem is formulated

The paper analyzes the influence of various disturbing components arising from a temperature shock of large elastic elements of a small spacecraft structure on the level of microaccelerations of the internal environment. The stability loss of a flat equilibrium shape of an elastic element of a small spacecraft is considered, as well as its all-round expansion when it moves from the shadow area to the

Under both normal gravity and microgravity conditions, pool boiling is an efficient mode of heat transfer which has been widely applied in practice. Studying the influence of gravitational acceleration on boiling heat transfer is not only of academic significance, but also helpful for the design of space equipment related to boiling. With the development of computer technology, numerical method has

We report experimental evidence of circulation reversal in evaporating drops. The internal flow patterns and particle distribution inside the evaporating water droplet with suspended polystyrene particles was studied using the Particle Image Velocimetry (PIV) technique. Droplet placed on externally heated substrate showed two symmetric and counter rotating Marangoni convection cells at the beginning

Clustering of small rigid spherical particles into particle accumulation structures (PAS) is studied numerically for a high-Prandtl-number (Pr = 68) thermocapillary liquid bridge. The one-way-coupling approach is used for calculation of the particle motion, modeling PAS as an attractor for a single particle. The attractor is created by dissipative forces acting on the particle near the boundary due

Steady-state measurements in a thermogravitational microcolumn using optical digital interferometry are presented here for the first time in the literature in the case of ternary mixtures. These measurements enabled the subsequent obtaining of thermodiffusion coefficients of a ternary mixture once convection reaches the steady-state. The ternary mixture used was the benchmark one, tetrahydronaphthalene

Wetting and the interaction between liquid and solid phases are significantly affected by gravity. In recent years, Chinese scientists have carried out wettability experiments in space, but the limitations of experimental facilities have hindered their ability to carry out in-situ observations of the dynamic process of wettability in space. The future Chinese space station will provide a platform for

Investigation of the natural convection in a dielectric fluid confined inside a vertical slot subject to a constant horizontal temperature gradient and a high-frequency electric field was revisited. The thermoelectric coupling produces a dielectrophoretic force which contains a term called electric buoyancy associated with an electric gravity. Similar to the Archimedean buoyancy, this force can induce

The development of space experiment payload for studying thermocapillary convection in the liquid bridge with large Pr number on TG-2 space laboratory as well as the experiments are presented in detail in this paper, and the objectives of the space experiments are confirmed. The functions of the payload are analyzed, and the technical and engineering specifications are determined. Detailed designs

Artificial Gravity generated by Short Arm Human Centrifuges is a promising multi-system countermeasure for physiological deconditioning during long duration space flights. To allow a continuous assessment of cardiovascular hemodynamics during centrifugation, a telerobotic robotic system holding an ultrasound probe has been installed on a Short Arm Human Centrifuge. A feasibility study was conducted

The linear stability of thermocapillary flow in a rotating annular pool at intermediate Prandtl number (Pr = 1.4) was studied over a wide range of rotation rate. The critical Marangoni number for the onset of flow instability was determined using linear stability analysis based on the spectral element method. The results indicate that the pool rotation can stabilize the thermocapillary flow and affect

The European Low Gravity Research Association (ELGRA) and the European Space Agency (ESA) co-organise since 2016 a Summer School on gravity-related research in the frame of ESA Academy’s Training and Learning Programme. This Summer School is organised every year, in June, at the ESA Education Training Centre located in ESA’s European Space Security and Education Centre (ESEC), Belgium. The Summer School

A magnetic thermostat employing soft-ferromagnetic particles and a varying magnetic field has been developed to investigate a homogeneous granular gas system in microgravity. While the thermostat’s mechanism of creating homogeneous distribution of the particles was shown earlier, its characteristics have not been understood well due to limited access to a microgravity environment. Therefore, a parametric

Biological membranes, especially the plasma membrane, are considered to be the most sensitive to altered gravity in regard to their properties and functions. We studied the composition and content of lipids, fatty acids and sterols in the plasma membrane fractions isolated from epicotyls and roots of Pisum sativum seedlings grown during 7 days under simulated microgravity by slow clinorotation. We

The theoretical model of the evaporation and condensation heat transfer process of the axially grooved heat pipe (AGHP) assisted by gravity under small angle inclination is established to investigate the evaporation regimes and the heat transfer characteristics of AGHP. To reveal the heat transfer mechanism of the AGHP, the working state and gas-liquid interface distribution of the AGHP with different

The inhibition of the cytotoxicity of NK cells by microgravity in space is of serious concern to the health of astronauts. However, there remains a lack of in-depth research into the mechanisms of action of this suppression. In the present study, the effects of simulated microgravity (SMG) on the morphology, survival rate and the ability of NK cells to kill were studied initially and then the mechanism

An experiment of axial temperature test for a heat pipe subjected to discrete heating sources is performed for deep understanding of the thermal characteristics of axial dovetail grooved heat pipe during the unsteady and steady state. The influences of heating length, heating source position, source configurations and incline angle on the temperature profiles, heat transfer limit of the heat pipe under

Thermocapillary migration of a droplet under thermal radiation with a uniform flux is numerically investigated and theoretically analyzed. By using the front-tracking method, it is observed that thermocapillary droplet migration at small Reynolds numbers and moderate Marangoni numbers reaches a steady process. The steady migration velocity decreases as Marangoni number increases. The time-evolution

In order to accurately calibrate the static error model coefficients of three gyroscopes simultaneously, especially the higher-order coefficients, in an inertial measurement unit, an optimal 16-position method is designed. Analysis is conducted using a precision centrifuge with a counter-rotating platform, and coordinate systems are established on centrifuge. Thus, centrifuge error sources, which may

This paper analyzes the possibility of obtaining the selective transport of microparticles suspended in air in a microgravity environment through modulated channels without net displacement of air. Using numerical simulation and bifurcation analysis tools, we show the existence of intermittent particle drift under the Stokes assumption of the fluid flow. The particle transport can be selective and

The paper is devoted to the study of the reasons of anomalous transport observation in the experiments with microchannels. Usually, retardation of such transport is associated with the interaction of solute particles with channel walls. In the present paper, we have shown that the viscous interaction of the flow and solid wall can be the reason for the anomalous transport observation. It was illustrated

The space-based gravitational wave detectors at low frequencies has received great attention recently. Due to lack of considering the relative motion between spacecrafts, the accuracy of current sensitivity models is inadequate for space-based gravitational wave detectors. In this paper, an accurate sensitivity model of the space-based gravitational wave detector is established by taking into account

Reduced gravity droplet combustion experiments were performed on the International Space Station (ISS). The data from these droplet combustion experiments have been made publicly available by NASA. These experiments utilized narrow-band and wide-band radiometers to measure thermal radiation heat fluxes from flames. The initial set of radiometers, which were used in 80 experiments, exhibited large noise

This paper investigates the Rayleigh Benard instability of a viscous, Newtonian, Boussinesq fluid with time-periodic boundary temperature modulation using the framework of weakly nonlinear theory. Critical Rayleigh number is computed for asymptotic stability criterion using the energy method accompanied by variational algorithm. Subcritical instability is found to occur under two conditions: when modulation

Phase separation in space is critical for gas-free propellant supply, life support systems, refueling of spacecraft in low earth orbit (LEO), and for deep space exploration missions. In the absence of gravity, the stability of the liquid-gas interface depends on capillary forces. High liquid flow rates, sudden accelerations, and vibrational disturbances can cause the free surface of the liquid to collapse

The nonlinear dynamics of gravity-driven two-layers flow through an oblique microchannel of porous walls subjected to an external electric potential is examined. The evolution equation governing the surface wave deflection is derived in the frame of long wave theory. The stability criteria of the linearized system are investigated. As permeability, inclination or dielectric constant increase, the disturbances

Thermodiffusion of a binary electrolyte situated in the microgap between two ion-selective surfaces under external electric field is theoretically studied. It is assumed that temperature gradient occurs only by Joule heating of the electrolyte; and the concentration gradient may trigger an inner gravitational instability. There are three types of instability in such setup: electrokinetic, thermoelectrokinetic

Due to potential applications in numerous fields (self-cleaning, anti-frosting, condensation enhancement, etc.), coalescence-induced droplet jumping has been investigated extensively by numerical simulations and experiments over the past decade. In this paper, the jumping dynamics of coalesced droplets on the microstructured superhydrophobic surfaces is simulated using the lattice Boltzmann model.

The Cold Atom Laboratory on the International Space Station produces ultracold gases of rubidium and potassium in a tight magnetic trap near the surface of a magnetic chip. In order to use these samples in long-duration field-free experiments, the atoms must be moved away from the chip, expanded to larger volume, and released from the trap. We describe how these goals can be achieved using quasi-adiabatic

Because the absence of sedimentation in zero-gravity makes the culture and the manipulation of cells or particles challenging, an attractive alternative is to use the Acoustic Radiation Force (ARF) as an artificial “acoustic gravity.” To evaluate the potential of this approach we studied the behavior of dense gold nanorods under ARF during a parabolic flight campaign. Using dense objects enhances the

This paper aims at the investigation of acoustic streaming produced by surface acoustic waves (SAWs) in a drop. Computational simulation of acoustofluidic phenomenon, using lattice Boltzmann method (LBM), presenting acoustic applications in flow control, and a relatively complete parametric study are the motivations of this work. For this purpose, a computational fluid dynamics modeling based on multi-relaxation

The paper presents the results of theoretical and experimental studies of thermal convection in a rotating horizontal cylindrical liquid layer. A layer with boundaries of different temperatures both when heating from inside and outside is considered. Steady thermal convection is determined by two mechanisms: thermovibrational and centrifugal ones. The first one appears due to oscillations of nonisothermal

Access to earthbound weightlessness is critical to many branches of applied sciences. Besides, several space systems require microgravity testing before their launch. Existing solutions (drop towers, parabolic flights, sounding rockets) offer variable durations and qualities of microgravity environment, but their cost and lead times make them unpractical for small actors such as universities or start-up

Plant biology is an important area for the future of space exploration, but biological spaceflight experiments have been always constrained by the hardware capabilities. The European Modular Cultivation System (EMCS) unit was an incubator for small organisms, such as Arabidopsis thaliana, built by the European Space Agency (ESA) and was decommissioned in 2018. Here, we describe the FixBox system as

This paper refers to studying the effect of microgravity on the friction behavior of friction units and to further analyzing the influencing mechanism. The potential factors affecting the friction behavior of the moving joints of space mechanisms in microgravity environment were analyzed. A friction apparatus was designed and manufactured by reducing the complexity and costs. A microgravity test program

A simplified method for measurements of low interfacial tension coefficient which is applicable for binary mixtures is proposed. The technique is based on generating progressive capillary waves at a liquid interface by radiation pressure of a short ultrasound pulse in microgravity condition. The waveforms are then processed in the spatial domain. The method presents the advantage of strongly reducing

Vapor compression heat pump technology has great potential in future space thermal management application. Considering microgravity in space, this paper proposes using aerostatic bearings for the lubrication of the heat pump compressor. An experimental apparatus was built to study the performance of a rotor supported by aerostatic bearings subjected to microgravity. The gravity-independent experiment

A series of experiments were conducted in the 3.6-s microgravity drop tower and normal gravity to investigate the effect of solid fuel curvature, conduction, and reradiation on the flame extinction of spherical polymethyl methacrylate (PMMA). In the semi-quiescent microgravity environment, flame extinction was observed if the PMMA diameter was larger than 40 mm, because of a smaller flame conductive

The present study is an overview of the surface properties of liquid Al-Ni alloys, which are of great importance for the design and development of new Al-Ni and Ni-based industrial alloys, widely used as functional and structural materials. The solidification and thus, the microstructural evolution are directly dependent on the interface/surface properties of metallic melts. Therefore, numerical simulation

The oscillation of liquid/gas free surface in a partially filled storage tank caused by an abrupt drop of gravity level is of critical importance for the fluid management in space. In the present study, the dynamic behavior of free surfaces in a model tank (tube) is numerically investigated using volume of fluid (VOF) method in the context of dynamic contact angle (DCA) model. It is concluded that

This paper examined the fluid transport on boundary layer near a vertical wall with thermal radiation effect. The coupled nonlinear partial differential equations are reduced to a system of ordinary differential equations through similarity transformation. The resultant system of ordinary differential equations is integrated with maple software using RKF45 method. The effect of the active parameters

The problem of cross diffusion (Soret/Dufour) and internal heat generation effects on combined convection flow of non-Newtonian fluids flow over the vertical wedge in a saturated porous medium with the entire regime is solved numerically. The internal heat generation is assumed to be an exponential decaying form. The power law model of Ostwald-de-Waele for non-Newtonian fluids is considered here. The

The sloshing free vibrations and the Equivalent Mechanical Model (EMM) parameters are determined for 2D multi-baffled containers under low-gravity conditions using Boundary Element Method (BEM) and potential flow model of the fluid. The presented model is applicable to any values of the acceleration of gravity and surface tension and to constant cross-section containers with arbitrary geometry, and

The impact of vibrations on the dynamics of a system of two immiscible liquids filling a rotating container is studied experimentally. A horizontal cylindrical container is rotating at a rate sufficient for the liquids, whose densities are not equal, to become steadily distributed in the form of core and annulus. The vibrational motion of the container has a frequency virtually equal to that of rotation

The paper is devoted to numerical simulation of nonlinear regimes of a binary liquid mixture in rectangular cavities elongated in the horizontal direction. The boundaries of the cavity are considered to be rigid, impermeable to the substance. The vertical boundaries are thermally insulated; constant different temperatures corresponding to heating from below are maintained on the horizontal boundaries

The stability of thermocapillary flow in a liquid bridge made from 5cSt silicone oil (Pr = 68) is computed numerically. To improve the numerical model as compared to the standard approach, we consider the flow in the liquid bridge fully coupled to the flow in the ambient gas, temperature-dependent material parameters, and a dynamically deforming liquid–gas interface. We address the full two-phase-flow

The paper proposes algorithms for controlling the orbital motion of a small spacecraft for executive bodies with constant and variable thrust. The developed algorithms are aimed at neutralizing the influence of temperature shock on the level of microaccelerations in the area of technological equipment. The influence of the most significant part of the disturbances associated with a change in the size

As a simple, fast and effective 3D printing method, direct-ink-writing (DIW) has potential applications in repairing the circuit board in orbit, printing the wearable devices for the astronaut, and producing the solar cells for the energy supply in space. To expand the DIW technology to space, we designed the colloidal material box (CMB) as the prototype printer of DIW and verified its applicability