Changes In Heat Flux Research Articles

Mechanism analysis of turbulent convective heat transfer of supercritical carbon dioxide in serpentine tubes

This study examines turbulent convective heat transfer in serpentine tubes, a critical topic given their widespread use in supercritical carbon dioxide (SCO2) cycle heat exchangers. Despite their importance, this area remains underexplored. The novelty of this work lies in analyzing various serpentine tube orientations to optimize heat exchanger design under different mass and heat fluxes. Using a validated numerical method, the study explores the impact of SCO2 thermophysical variations on gravitational and centrifugal forces. Furthermore, heat transfer effects are evaluated by analyzing Morton and Dean vortices as well as Richardson numbers under various conditions. The results show that changes in mass and heat fluxes have a greater impact on the gravitational Richardson number than on the centrifugal Richardson number. When both effects are considered together, the Richardson ratio increases with higher mass and heat fluxes, emphasizing the dominance of centrifugal force over gravitational force. The study also found that changes in SCO2 flow direction most significantly affect the thermal and hydraulic characteristics of serpentine tube in a vertical orientation. The improvement index reaches values of 1.13, 2.38, and 3.26 at heat fluxes of 20, 40, and 60 kW/m2, respectively. However, under conditions of low mass fluxes and high heat fluxes, the serpentine tube with a lateral orientation and downward SCO2 flow demonstrates optimal overall performance. In this configuration, the performance index for thisconfiguration increases by up to 15 % at a heat flux of 60 kW/m2.

Changes in the SST Seasonal Cycle in a Warmer North Pacific without Ocean Dynamical Feedbacks

Abstract Climate models project a significant intensification of the sea surface temperature (SST) seasonal cycle over the subpolar North Pacific due to global warming, with the shallower mixed layer widely recognized as the dominant factor. However, employing slab ocean experiments with only ocean–atmosphere thermal coupling, we find a substantial contribution from changes in surface heat flux to this seasonal cycle intensification. In particular, the stronger Newtonian cooling effect in winter acts as a more potent damping than in summer. This differential damping inhibits the warming in colder seasons, significantly contributing to the intensified SST seasonal cycle in the subpolar North Pacific. In addition, consistent phase shifts in the North Pacific are identified across CMIP6 models. In the northwest North Pacific, a phase advance is associated with anomalous heating in early spring, driven by enhanced warm atmospheric advection from lower latitudes and sea ice melting in marginal seas. In contrast, the southeast North Pacific exhibits a phase delay attributed to the anomalous cooling in spring relative to autumn. This cooling is due to weakened trade winds and increased presence of high clouds. The former leads to stronger evaporative cooling in spring, while the latter impedes shortwave radiation from reaching the ocean.

Analysis of convection and boil-off in multi-scale membrane LNG tanks under sloshing excitations

The marine storage and transportation of liquefied natural gas (LNG) in membrane tanks involves complex thermodynamic responses, significantly affecting system operation reliability. The study investigates the coupled problem of heat transfer and sloshing in LNG tanks through small-scale experiments and simulations. A tank partially filled with R134a was analyzed under various non-isothermal sloshing excitations to examine the free surface, flow, and heat transfer. Changes in fluid temperature, wall temperature, and heat flux were measured under different sloshing frequencies, amplitudes, and filling levels. A Computational Fluid Dynamics (CFD) analysis was performed, considering heat flow in the insulation layer and phase changes in the membrane tank. The tank was assumed to be vented. A Volume-of-Fluid (VOF) model with a dynamic mesh provided insights into the effects of sloshing on heat transfer and flow. Model feasibility was confirmed by comparing simulation results with fluid sloshing experiments. An extended sloshing Nusselt number was calculated, and a correlation formula related to sloshing conditions was developed, allowing for a quantitative assessment of enhanced heat transfer. Simulations explored evaporation characteristics in various scales of LNG tanks under static and sloshing conditions. The results showed that the evaporation rate of LNG increases as the tank scale decreases, with sloshing significantly impacting LNG storage and transportation. The study enhances the understanding of heat transfer and flow evolution in LNG tanks, improving the accuracy of evaporation models and providing insights for optimizing tank design and operation under sloshing conditions.

Revisiting the inconsistent influence of El Niño-Southern Oscillation on the equatorial Atlantic

Abstract The impact of El Niño-Southern Oscillation (ENSO) on the equatorial Atlantic Zonal Mode (AZM) is investigated using two atmospheric reanalysis products and 44 models from the Coupled Model Intercomparison Project Phase 6 (CMIP6). While the impact of ENSO on equatorial Atlantic SST is inconsistent, as previously reported, there is a very robust influence of decaying ENSO events in boreal spring on the contemporaneous surface zonal winds over the equatorial Atlantic, with El Niño events associated with anomalous easterlies that cool the equatorial Atlantic. This dynamic impact is counteracted by a thermodynamic impact, in which El Niño events cause changes in surface heat fluxes that lead to warming over the tropical Atlantic. The thermodynamic influence is active throughout the lifecycle of the ENSO event, but the dynamic influence is highly seasonal with a pronounced peak in boreal spring. Thus, a quickly decaying El Niño event will lead to warming, while a slowly decaying event will lead to cooling in the equatorial Atlantic. The ENSO-AZM relation is further complicated by partially independent Atlantic variability, in particular that associated with the South Atlantic subtropical dipole (SASD). Prediction experiments with a simple linear regression model support the role of the SASD as an AZM precursor. Many CMIP6 models show skillful predictions of the June-July-August AZM based on SST indices in the preceding December-January-February, with correlations above 0.5. When predictions are restricted to ENSO years, even more models exceed this threshold, but skill in the reanalyses remains relatively low, possibly due to insufficient training data.

Competing effects of wind and buoyancy forcing on ocean oxygen trends in recent decades

Ocean deoxygenation is becoming a major stressor for marine ecosystems due to anthropogenic climate change. Two major pathways through which climate change affects ocean oxygen are changes in wind fields and changes in air-sea heat and freshwater fluxes. Here, we use a global ocean biogeochemistry model run under historical atmospheric forcing to show that wind stress is the dominant driver of year-to-year oxygen variability in most ocean regions. Only in areas of water mass formation do air-sea heat and freshwater fluxes dominate year-to-year oxygen dynamics. The deoxygenation since the late 1960s has been driven mainly by changes in air-sea heat and freshwater fluxes. Part of this deoxygenation has been mitigated by wind-driven increases in ventilation and interior oxygen supply, mainly in the Southern Ocean. The predicted slowdown in wind stress intensification, combined with continued ocean warming, may therefore greatly accelerate ocean deoxygenation in the coming decades. The fact that the model used here, along with many state-of-the-art forced ocean models, underestimates recent ocean deoxygenation indicates the need to use forcing fields that better represent pre-industrial conditions during their spin-up.

A numerical study of the effect of graphene nanoparticle size on brownian displacement, thermophoresis, and thermal performance of graphene/water nanofluid by molecular dynamics simulation

Brownian motion, often known as BM, is an inherent characteristic of minute particles suspended in a fluid. It plays an important role in several physical and chemical processes. Thermophoresis refers to the process where particles in a fluid are carried along with a gradient in temperature (Temp). This feature has significant importance in several applications, including microfluidics, thermal control, and energy conversion. Through the examination of the thermophoresis phenomenon in water/graphene nanofluid (NF), researchers might get valuable knowledge on the potential uses of these materials. The current study examined the effect of various sizes of graphene nanoparticles (NPs) (5, 6, 9, and 10 Å) on the thermal behavior (TB), BM, and thermophoresis of water/graphene NF using molecular dynamics (MD) simulation. This study reported the changes in heat flux (HF), thermal conductivity (TC), average Brownian displacement (BD), and thermophoresis. It is concluded that by increasing the size of graphene NPs from 5 to 10 Å, the average BD and thermophoresis increased from 3.06 Å and 23.88 Å to 4.16 Å and 31.46 Å, respectively. Due to their higher kinetic energy (KE) and momentum, larger graphene NPs experienced more BM, enabling them to withstand random thermal fluctuations more effectively than smaller particles. In addition, as the size of graphene NPs increased, the HF and TC values ​​increased from 39.54 W/m2 and 0.36 W/(m.K) to 47.19 W/m2 and 0.51 W/(m.K) after 10 ns. Therefore, the size-dependent changes in BD and thermophoretic effects led to a simultaneous increase in HF and TC of the NF, which was attributed to the larger heat transfer (HT) surface area, improved HT properties, and synergistic effects of larger graphene NPs. The maximum (Max) temperature increases from 1415 K to 1504 K. These findings were useful in a variety of industries, particularly for improving TB in different NFs.

Response of the upper ocean to northeast Pacific atmospheric rivers under climate change

Atmospheric rivers are important transport vehicles for Earth’s water cycle. Using a high-resolution, eddy-resolving Earth System Model, atmospheric river impacts on the upper ocean are investigated by analyzing historical and climate change simulations. For atmospheric rivers along the North American coastline, strong winds cause significant dynamic and thermodynamic upper ocean responses. They push ocean water towards the coast, measured by sea surface height, a process that is amplified under climate change. Mixed layers are deeper upstream of atmospheric rivers, and shallower downstream, however for climate change, shoaling downstream is subdued. Air-sea heat fluxes tend to promote ocean cooling upstream and warming downstream, although different regions have different climate change heat flux signals. Southern California heat flux changes due to warming are driven by evaporative processes and strengthen the ocean responses seen in historical simulations. The regions north are primarily dominated by sensible heat flux changes and counter the historical patterns.

Design and Verification of Thermal Control System of Communication Satellite

The multiple working modes, complex working conditions, frequent changes in external heat flux, and high power consumption of communication satellites all pose great difficulties to their thermal design. This paper mainly describes the design of a thermal control system for high-power communication satellites. Firstly, new efficient heat transfer technologies and thermal control materials for spacecraft are introduced. Secondly, the structure and internal heat source of the satellite are introduced. Thirdly, the external heat fluxes are analyzed, and the position of the heat dissipation surface and extreme conditions are confirmed. Then, a thermal control system is designed around the difficulties of thermal control. With heat pipes, the temperature uniformity of +Y deck, −Y deck, and +Z deck increased by 8 °C, 9.9 °C, and 34.2 °C, respectively. Furthermore, the maximum temperature of the power controller, secondary power supply, bidirectional frequency converter, and solid discharge decreased by 32.5 °C, 22.0 °C, 14.0 °C, and 164 °C, respectively. Finally, a thermal balance test is performed. The test results show that the temperatures of the solid-state power amplifier, on-board computer, power controller, secondary power supply, and bidirectional frequency converter meet the requirements of the thermal control indices. In addition, the temperature of thermal-sensitive components such as batteries and the storage tank also meets the requirements. The thermal design scheme is reasonable and feasible, and the thermal balance test verifies the correctness of the thermal design.

On the analysis of static thermal instabilities occurring in two-phase flow systems

In this study, we investigate a novel type of static thermal instability that occurs in two-phase flow systems. The instability is theoretically and experimentally confirmed to occur for flow boiling micro-channel scenarios and flow condensing scenarios. The theory presented is independent of the evaporator geometry as well as flow boiling/condensing situations. A stability criteria is derived using a Reynolds Transport approach applied to the evaporator of a two-phase pumped loop (TPPL) system. The theory is then validated experimentally using a TPPL containing a parallel micro-channel evaporator. The instability is confirmed with pressure, temperature, and void fraction measurements acquired at the exit of the evaporator. The findings reveal that static thermal instabilities can arise when simultaneous heat addition and reduction in system saturation temperature occurs (or vice versa). The implications of the thermal instability result in dramatic changes in evaporator heat flux, as well as a flow transition from stratified laminar flow to vigorous turbulent flow with high void fractions. By identifying the additional instability mechanisms, this work contributes to enhancing system reliability and predictability of TPPL systems.

Thermal measurement of a unitized regenerative fuel cell during mode switching using thin film sensors

The research on temperature and heat flux during mode switching process of unitized regenerative fuel cells is importance. Thus, in this paper, the local temperature and heat flux are measured during mode switching using self-made thin film sensors, and heat transfer coefficient is also obtained. The results of the experiment exhibit that the temperature and heat flux change significantly during mode switching, and periodically change with periodic mode switching, the heat generation is greater than the heat dissipation inside the cell. During mode switching, the temperature and heat flux are higher in upstream, and the temperature and local heat transfer coefficient increase along main gas flow direction. The fuel cell current density has a great influence on heat transfer when cell mode switches. At different current density, the temperature and heat flux show different changing trend when the cell switches from electrolytic cell mode to the fuel cell mode. These experimental results can provide guidance to make fuel cell run more efficiently in practical application.

Two-Dimensional Inverse Method to Estimate the Heat Flux Function in a Phase Change Material Heat-Exchanger

A two-dimensional inverse method is presented for estimating the boundary heat flux imposed on phase change materials in the melting/solidification process. The inverse problem is handled by the conjugate gradient method with the adjoint problem for function estimation. The method is verified using unsynthetic data, and the effect of the number of sensors, sensor placement, and measurement errors on the accuracy is investigated. In all cases, it is found that the method remains stable and accurate with a root mean square relative error less than 10%. Also, the number of sensors depends on the desired accuracy, computing time, and frequency of spatial changes in heat flux. Using field measurement is the best option for high accuracy and time-efficient estimation of spatial changes in the heat flux function. The accuracy of the estimated heat flux strongly depends on the sensor distance from the boundary. Therefore, it is desirable to place the sensor as close to the boundary as possible. With the addition of measurement errors, the presented method remains stable even with high measurement errors. This shows that this method can be used for real conditions.

Initial Solidification Behavior of Spring Steel Billet Near the Mold Corner During Continuous Casting Process

Strand surface defects originate from the initial solidification of molten steel in continuous casting mold. This article investigates the initial solidification behavior during the continuous casting of 55SiCr spring steel billet using a novel mold simulator. First, the high‐frequency responding temperatures and high‐frequency heat fluxes across the mold corner and hot face are calculated by the 2D‐inverse heat conduction program mathematical model and the fast Fourier transformation, and the results indicate that the temperature variations and heat flux fluctuations around mold corner are stronger than those at mold hot face. Then, the characteristic heat fluxes around the meniscus at mold corner and hot face are analyzed, and their four corresponding signals are discussed with the help of power spectral density analysis. The average solidification factor K for shell corner is greater than shell face, which indicates that the cooling intensity of shell at corner is stronger due to the two‐dimensional heat transfer near mold corner, as demonstrated by heat transfer and dendrite structure analysis. Finally, the interrelations between the shell profile, mold oscillation, heat flux change rate, high‐frequency heat flux, temperature change rate, and high‐frequency temperature for the two cases are discussed.

The joint effects of the El Niño-Southern Oscillation and Arctic Oscillation on tropical Indian Ocean heat flux during boreal winter

In this study, the joint effects of the El Niño-Southern Oscillation (ENSO) and Arctic Oscillation (AO) on winter net surface heat flux (Qnet) anomalies over the tropical Indian Ocean (TIO) are investigated for the 1979/1980–2017/2018 period. The results show that, in multisource datasets, the Qnet pattern for El Niño plus positive AO cases is the most robust. The major feature of Qnet is dominated by a significant dipole pattern, with oceanic heat gain anomalies appearing over the southeastern TIO and oceanic heat loss near the western TIO. Analysis of the flux components shows that the Qnet anomalies are mainly contributed by changes in latent heat flux and shortwave radiation (QLHF and QSWR), which are tightly associated with the regional atmospheric and oceanic conditions. In association with positive AO, northerly wind anomalies on the eastern flanks of a low-level anomalous anticyclone in the Arabian Sea enhance the intertropical convergence zone (ITCZ) in the western TIO. Meanwhile, the El Niño-related SST warming occurs in the western TIO. Both enhanced ITCZ and anomalous SST warming favour in situ increased low and middle cloud cover and a reduced QSWR. Furthermore, under El Niño's effect, a low-level anomalous anticyclone located in the southeastern TIO leads to a positive QLHF through decreased near-surface wind speed and increased near-surface air humidity. As a result, a dipole Qnet pattern tends to be observed for the combination of El Niño and positive AO.

Strengthened impact of late autumn Arctic sea ice on Asian winter cold extremes after 1999/2000

Winter cold extremes (WCEs) frequently plague densely populated areas of Asia, leading to substantial economic losses and even fatalities. It has been found that the late autumn sea ice concentration (SIC) anomalies in the northern (SICN) and southern Arctic (SICS) are significantly positively and negatively correlated with the occurrence frequency of WCE in Asia, respectively (Wang and Su 2024). Our study demonstrates that the impacts of SICN and SICS have strengthened after 1999/2000. Specifically, before 1999/2000, the influences of SICN and SICS on the Asian WCE (AWCE) were relatively weak, possibly related to the weak intensity of SICS and the limited correlation between SICN and SICS. After 1999/2000, the interannual variability of SICS became larger and anti-correlated with that of SICN, resulting in a stronger teleconnection between the Arctic SIC and AWCE. It is revealed that after 1999/2000, the greater loss of SICS modified atmospheric stability through changes in surface heat fluxes and surface upward longwave radiation fluxes. This alteration weakened the magnitudes of westerly winds and increased the frequency of blocking events over the northern Eurasian continent, leading directly to a higher occurrence of cold extremes in Asia. These interdecadal differences in the influence of Arctic SIC on AWCE may be associated with long-term climate change.

The Inter‐Model Uncertainty of Projected Precipitation Change in Northern China: The Modulating Role of North Atlantic Sea Surface Temperature

AbstractPrecipitation changes in northern China are projected to increase in the Coupled Model Inter‐comparison Project Phase 6 (CMIP6) multi‐model ensemble. However, these projections are accompanied by notable inter‐model uncertainty, and the sources of this uncertainty remain largely unexplored. By analyzing 30 CMIP6 models, this research explores the source of inter‐model uncertainty in projected precipitation change and reveals the fundamental mechanism driving uncertainty spread. Following the empirical orthogonal function of inter‐model projected precipitation change, the leading mode displays a seesaw spatial pattern between northwest and north China. This phenomenon predominantly stems from the inter‐model divergence of projected sea surface temperature (SST) warming in the North Atlantic. Further scrutinizing the ocean mixed layer heat budget, we discover that the combined effect of surface sensible heat flux, net surface shortwave radiation flux, and ocean heat transport convergence influences heat flux and SST change of North Atlantic. The multi‐model projections indicate that localized increases in solar radiation and heat convergence warm sea surface, raising SST and initiating convective motion. This convective motion subsequently transforms the 200 hPa teleconnection wave train, leading to an anti‐phase pattern over northern China. This wave pattern modulates total cloud cover percentage, influences surface upward latent heat flux, and adjusts the top of atmosphere outgoing longwave radiation, collectively resulting in the seesaw pattern. Our study underscores the pivotal role of inter‐model disparities in North Atlantic SST warming projection, which is a primary driver of precipitation uncertainty in northern China. These insights offer an essential foundation for refining and diminishing inter‐model uncertainty.

Influence factors of frictional heat between bristles and rotor for a multi-stage brush seal

Frictional heat generates at frictional surface caused by contact between bristles of brush seal and rotor, which leads to early failure of the seal, especially downstream stage of multi-stage brush seal (MBS). In this paper, a three-dimensional tube bundle model of the MBS was established to study change of heat flux on the frictional surface among stages, internal temperature distribution of bristles and leakage flow characteristics of the seal. Moreover, three control strategies (i.e., increasing height of backing plate to rotor hbp, decreasing interference between bristles and rotor Δr and decreasing axial width of bristle pack wab) were analyzed to further investigate influence mechanism of the frictional heat. Results showed that the frictional heat at bristle tips mainly depend on formation of frictional heat caused by friction between bristle tip and rotor, transfer of heat from upstream stage to downstream one and dissipation of heat with flow of the airflow passing through the seal. For a traditional MBS with same structural single-stage seal units, a remarkable increasing bristle temperature at bristle tip of downstream stage and an increasing vortex area of airflow with higher temperature in chambers implied accumulation of the frictional heat at the downstream stages. Increase of hbp enhanced dissipation of the heat due to increasing passage area of airflow. Both decrease of Δr and decrease of wab obviously reduced bristle temperatures at downstream stages due to decreasing formation of the frictional heat. Furthermore, the decrease of wab had a lower bristle temperature compared to the increase of hbp, indicating a higher impact of the frictional heat formation on bristle temperature at downstage stages.

Heat Flow Overshooting in Suspended Graphene

ABSTRACT In this work we found that when the hydrodynamic heat conduction in suspended graphene is in the under-damped free oscillation regime the disturbance of heat flux at the boundaries of graphene and the joint action of the initial heat flux and its time change rate can cause the heat flow overshooting which refers to the excess heat flux established in the heat conduction medium when two heat flow wave-fronts meet. The overshooting can make the maximum amplitude of the heat flux more than twice that of the initial heat flux, which poses a great danger to the next high-frequency and high-efficiency electronic devices based on graphene, such as the graphene field-effect transistors. Interestingly, results show that when the scale ratio of graphene with rectangular shape in the heat flow direction to its vertical direction is greater than a certain value, the overshooting caused by the disturbance of the heat flux at the boundaries no longer occurs. For the overshooting induced by the uneven distribution of the initial heat flux and its time change rate, it is shown that if the length in the region with the higher heat flux and time change rate in the direction of heat flow is less than a critical value the overshooting phenomenon can be avoided. These findings provide a new way for thermal management of electronic devices based on graphene.

Advancements in design of radiant floor heating systems with an innovative simplified calculation method

The calculation accuracy of existing simplified methods for radiant floor heating systems (RFHS) is far from meeting the growing demand for energy saving. Therefore, an innovative steady-state simplified method is proposed based on conduction shape factors, equivalent thickness, and mirror principle. The new model is validated by experimental data and compared with an equally simple simplified method. Meanwhile, the effects of the total heat-transfer coefficient of radiant surfaces and fluid flow rate in heating pipes on the calculated results are discussed. The calculation flowchart is given. Parameter influence and sensitivity analysis are then performed. The results show that the new simplified model agrees well with experimental data, and the maximum relative error is 7.9% for heat flux and 2.0% for surface temperature. Standard deviation reduces by 68.5% and 66.8% for the heat flux and surface temperature, respectively, compared to the equally simple existing simplified method. With the same absolute increment of pipe pitch, the smaller the pipe spacing, the faster is the heat flux and surface temperature change. The order of importance of influential parameters is mean water temperature > indoor air temperature > pipe pitch > thermal conductivity of filling layer > thermal conductivity of pipe wall.

Study on thermal runaway propagation inhibition of battery module by flame-retardant phase change material combined with aerogel felt

Phase change materials (PCMs) are susceptible to fire and may accelerate heat transfer when thermal runaway propagation (TRP) in lithium-ion battery (LIB) modules, requiring the design and safe use of insulation structures with excellent flame-retardant properties. In this work, the sandwich structure composed of flame-retardant phase change material (FRPCM) combined with aerogel felt (AEGF) is used to study the inhibitory effect on TRP of pouch battery modules (BMs). The structural materials are applied between cells, and the changes of temperature, voltage, mass and other parameters in the TRP process are analyzed by changing the thickness of FRPCMs and AEGFs, and the changes of heat flux of materials were also qualitatively analyzed. The results show that the increase of FRPCM and AEGF thickness can increase the interval time of TRP and reduce the overall thermal risk of the BMs. Compared to Test-1, the increase in TRP time between cells 1 and 2 in Test-2 to Test-5 ranged from 52.7% to 358.7%, and the longest thermal runaway interval reached 844 s. Both the structural materials in Test-6 and Test-7 block the TRP. Combining the thermal conductivity of PCMs and the thermal insulation properties of AEGFs, this work can effectively conduct heat to the environment and block the TRP when applied to BMs, which provides a valuable reference for efficient inhibition and blocking of TRP.

Investigating combined effects of varying gravity and heat flux direction on the melting dynamics of phase change material in space

The present work investigates the combined effect of varying gravity and heat flux direction with respect to gravity on the melting dynamics of Phase Change Material. Similar conditions are relevant to applications in space, at different space infrastructures, such as orbiting satellites, as well as various extraterrestrial surface assets, landers, and rovers. The numerical simulations are performed to study the melting dynamics of a paraffin-based phase change material with Prandtl number Pr ≈ 71 and Stefan number Ste ≈ 0.33 inside a differentially heated square enclosure. The mathematical model employs a control volume-based enthalpy porosity approach to simulate the melting process inside enclosure. The direction of the incoming heat flux relative to the gravity vector is defined in terms of an orientation angle, which is varying circularly with a step of 45°, whereas the gravity level is ranging from the terrestrial surface value g to 0.2g to analyze the melting process over a wide range of Rayleigh number 100 ≤ Ra ≤ 107. The study provides a detailed insight into the attributes of heat transfer, flow dynamics, and energy storage, along with a quantitative analysis of the transition between various melting regimes and temporal fluctuations in the performance parameters. The findings demonstrate that the mutual orientation between the directions of incoming heat flux and gravity, as well as the value of the latter, significantly affect features of the convective motion in the liquid phase, as well as the entire thermally driven heat transfer within the domain. In particular, for the oppositely directed gravity and heat flux, the melted fluid closely resembles Rayleigh-Bénard convection with the presence of multicellular flow structures, while at other orientation angles, except for a co-directed gravity and heat flux case, a circular convective motion of the melted fluid takes place. The results of numerical simulations reveal declining melting rates as the mutual orientation of gravity and heat flux changes from opposite to co-directed and vice versa. The low gravity conditions delay the onset of convection-driven melting, reducing the melting rate significantly.