As a highly promising interface capture tool, the phase field method (PFM) has gained fast development in past 20 years or so including simulation of droplet impact. The mobility tuning parameter χ PFM, however, is hard to determine since it ambiguously reflects relative strength between advection and diffuse effects that are difficult quantify. This problem becomes even more complex when coupled with contact line movement modeling, i.e., dynamic angle (DCA) model, which closely related...

Solar vapor generation, which uses photothermal materials to desalinate seawater by evaporation, is a promising technology mitigate the water scarcity problem, but its performance hindered large heat leak and salt accumulation problems. Here we report an umbrella evaporator that achieves efficient generation harvesting concurrently via double-sided evaporation reveal nucleation, growth, falling mechanism. The reaches rate of 1.25 kg m−2·h−1 under ambient conditions, continuous operation for...

Abstract Aiming to efficiently simulate the transient process of transpiration cooling with phase change and reveal convection mechanism between fluid porous media particles in a continuum scale, new two-phase mixture model is developed by incorporating local thermal non-equilibrium effect. Considering low-pressure high overload working conditions hypersonic flying, heat mass transfer induced capillary inertial body forces are analyzed for sub-cooled, saturated super-heated states water...

A novel Trunk-Branch (TB)-net physics-informed neural network (PINN) architecture is developed, which a PINN-based method incorporating trunk and branch nets to capture both global local features. The aim solve four main classes of problems: forward flow problem, heat transfer inverse learning problem within the porous medium, are notoriously complex that could not be handled by origin PINN. In proposed TB-net PINN architecture, Fully-connected Neural Network (FNN) used as net, followed...

Low-salinity water flooding of formation in rock cores is, potentially, a promising technique for enhanced oil recovery (EOR), but details the underlying mechanisms remain unclear. The salinity effect on interface between and was investigated here using molecular dynamics (MD) simulation method. n-Decane selected as representative component, SPC/E all-atom optimized potentials liquid simulations (OPLS-AA) force fields were used to describe water/oil/ionic interactions saltwater n-decane...

Abstract A new form of pancake bouncing is discovered in this work when a droplet impacts onto micro‐structured superhydrophobic surfaces an environment pressure less than 2 kPa, and unprecedented reduction contact time by ≈85% obtained. The mechanisms forming unique phenomenon are examined combining experimental observation, numeical modelling improved theoretical model for the overpressure effect arising from vaporisation inside micro‐scaled structures. competition among vapor effect,...

Physical properties of polyelectrolytes have been shown to be significantly related their chain conformations. Atomistic simulation has used as an effective method for studying polymer structures, but few simulations focused on the effects length and tacticity in presence monovalent salts. This paper investigated microscopic conformation behaviors poly(acrylic acid) (PAA) with different sizes, tacticities, sodium chloride concentrations. The hydrogen corresponding radial distribution...

Solar evaporation of seawater is promising to mitigate the fresh water scarcity problem in a green and sustainable way. However, salt accumulation on photothermal material prevents system continuous operation, supply driven by capillary force severely limits scale-up evaporators. Here, we demonstrate double-sided suspending evaporator with top surface distributor for high-efficient concurrent solar harvesting large area applications. Both sides can evaporate automatic from edge concurrently....

Regenerative cooling by endothermic hydrocarbon fuel (EHF) is one of the most promising techniques for thermal management supersonic or hypersonic aircraft. How to maintain working in proper states an important issue maximize potential EHT. This work proposes a novel state map, including risking zone (RZ), cracking (TCZ), supercritical (SupZ) and subcritical (SubZ), differentiate possible EHF during regenerative cooling. Using n-decane flowing circular tube as example, boundaries four zones...

One of the key challenges faced by hypersonic flying is complex thermal–mechanical–chemical coupling effect between thermal protection materials and non-equilibrium flow environment. Silicon carbide (SiC) has drawn much attention due to its superior physical chemical characteristics, performance under hyperthermal atomic oxygen (AO) impact, however, still little known. This work investigates effects various SiC crystalline polytypes, surface temperature, crystal orientations on interface...

The thermal protection system is essential for the safe and reliable flying of any high-speed aircraft. A carbon fiber-reinforced phenolic resin (PR) composite one most important matrix candidates ablative materials, microscopic understanding pyrolysis process PR, however, still remains poor. usual numerical approach based on volumetric while neglecting influence external hyperthermal surroundings. surface-volume coupled reactive molecular dynamics model established in this work to simulate...

Supercooled icing on solid surfaces is a universal phenomenon, which can be generally divided into five stages: liquid cooling (supercooling), nucleation, recalescence, solidification and cooling. The nucleation recalescence processes, are highly transient kinetically controlled, typically neglected in macroscopic simulation by assuming mass fraction at the end of recalescence. This work develops an alternative to simulate these non-equilibrium processes based Molecular Dynamics (MD) method...

Under hypersonic flow conditions, the complicated gas-graphene interactions including surface catalysis and ablation would occur concurrently intervene together with thermodynamic response induced by spacecraft reentry. In this work, competing effects of heterogeneous catalytic recombination characteristics at elevated temperatures are investigated using Reactive Molecular Dynamics (RMD) simulation method. A Gas-Surface Interaction (GSI) model is established to simulate collisions...