Liquid Volume Research Articles

Exploring the thermal shielding performance by coupling phase change material to liquid cooling plate

To enhance the thermal shielding performance of high-temperature heat source target, an evolved cold shield system coupling phase change material (PCM) and liquid cooling plate with serpentine flow channel is developed. The thermal shielding effectiveness of the proposed system is illustrated by comparing the duration maintained at a lower temperature on the cold surface, and the temperature uniformity of the cold surface is analyzed to describe the role of PCM in the thermal shielding performance. The influences of the operating parameters of the liquid cooling plate and PCM physical parameters on the thermal shielding performance of the heat source targets are investigated. The results indicate that coupling PCM to a liquid cooling plate can effectively improve the thermal shielding performance. Increasing the heat power of the heat source target from 190 W to 231 W will lessen the advantage time from 3090 s to 1980 s for the coupled system. The advantage time is shortened by 1500 s as increasing the liquid volume flow rate from 0.26 L/min to 1.30 L/min. Lifting the starting temperature of the coolant from 15 °C to 25 °C prolongs the advantage time from 2130 s to 3090 s. The advantage time is improved by 660 s as increasing the PCM phase transition temperature from 26 °C to 30 °C, and increasing the PCM covering thickness from 8 mm to 10 mm extends the advantage time from 1830 s to 3090 s. Meanwhile, the temperature equalization of the cold surface for the coupled system is better than the single liquid cooling. These results indicate that the proposed coupled system has potential applications in improving thermal shielding performance as well as heat flow control, thermal insulation, and other areas of heat regulation.

Capillary-Driven Microdevice Mixer Using Additive Manufacturing (SLA Technology)

This study presents a novel microfluidic mixer designed, fabricated, and characterized using additive manufacturing technology—stereolithography (SLA)—and harnessing capillarity principles achieved through microstructure patterning. Micromixers are integral components in optimizing mixing and reaction processes within microfluidic systems. The proposed microdevice employs a tank mixing method capable of blending two fluids. With a channel length of up to 6 mm, the process time is remarkably swift at 3 s, and the compact device measures 35 × 40 × 5 mm. The capillarity-driven working flow rates range from 1 μL/s to 37 μL/s, facilitated by channel dimensions varying between 400 μm and 850 μm. The total liquid volume within the device channels is 1652 mL (6176 μL including the supply tanks). The mix index, representing the homogeneity of the two fluids, is approximately 0.55 along the main channel. The manufacturing process, encompassing printing, isopropyl cleaning, and UV (ultraviolet) curing, is completed within 90 min. This microfluidic mixer showcases efficient mixing capabilities, rapid processing, and a compact design, marking it as a promising advancement in microfluidic technology. The new microfluidic mixer is a major step forward in microfluidic technology, providing a cost-effective and flexible solution for various uses. Its compatibility with SLA additive manufacturing allows for quick prototyping and design improvements, making it valuable for research and practical applications in chemistry, biology, and diagnostics. This study highlights the importance of combining advanced manufacturing techniques with basic fluid dynamics to create effective and easy-to-use microfluidic solutions.

Smoke deposition and extraction in compartment fires with different ignition sources

The paper presents the experimental research findings on the characteristics of smoke emission and deposition during compartment fires with different ignition sources: an open flame, a heated surface, local heating sources and exposed electrical conductors. The research involved the interior design and construction materials typical of residential and industrial premises: wood, linoleum and cardboard. Adaptive approaches were proposed to the creation of smoke deposition conditions at incipient fire stages using limited volumes of liquid. The foaming agent emulsion was found to be very effective for smoke suppression. The efficiency of several methods of smoke extraction using supply and exhaust ventilation was investigated. Efficient combined techniques of smoke extraction and deposition were identified. Smoke extraction was found to be most efficient at an air velocity of less than 3 m/s. The alternation of intermittent activation of the spraying system and supply and exhaust ventilation system is the most efficient method of smoke removal. Mathematical equations were derived to predict the characteristics of sprinkler and ventilation systems, providing effective smoke deposition and extraction.

Knee-to-chest flexion manoeuvre to reduce respiratory distress after planned caesarean birth: a feasibility study

BackgroundPlanned caesarean section (CS) is a risk factor for neonatal respiratory distress caused by a greater volume of airway liquid in the absence of uterine contractions.Performing a newly conceptualised knee-to-chest...

Cross-dimensional multi-physics model and two-phase mass-transport enhancement for the hydrogen peroxide-based fuel cell

The direct liquid fuel cell utilizing hydrogen peroxide as an oxidant is considered to be the promising energy conversion technology, owing to its superior energy density and theoretical voltage. In the hydrogen peroxide-based fuel cells, the ever-changing two-phase mass transport and multi-component reaction processes resulting from the hydrogen peroxide self-decomposition exerts a pivotal influence on their performance. In this work, taken hydrogen peroxide self-decomposition into account, a cross-dimensional multi-physics model for the hydrogen peroxide-based fuel cell was proposed and developed to clarify the complex mechanisms of transports and reactions. In this ingeniously developed model, the multi-component reaction in the porous electrode is elucidated by a two-dimensional (2D) sub-model, the two-phase mass transport in the flow field is captured by a three-dimensional (3D) sub-model, and the one-dimensional (1D) correlation equation is served as a bridge between them. The uneven distribution of gas–liquid volume, velocity and current density and their relationships in fuel cell with serpentine flow field and dot matrix flow field were thus achieved. Furthermore, a novel gradient dot matrix flow field was developed to match the two-phase mass transport and multi-component reaction processes of hydrogen peroxide-based fuel cell. It is found that the continuously increasing pressure and velocity along flow path is balanced by the gradient-downsized ribs and the formation of large-volume oxygen bubbles is prevented by the gradient-densified ribs, achieving obviously uniformized current density distribution. Moreover, the gradient dot matrix flow field enables 54 % higher average hydrogen peroxide coverage contents (49 %) and 86 % lower average pressure drop (172 Pa) compared to the serpentine flow field, yielding 6.3 % higher peak power density (210 mW cm−2) and ultra-low extra pump power in fuel cell. This work will make contribution towards gaining profound insights into the intricate mechanisms underlying mass and charge transport, and offering invaluable guidance for the flow field design for the hydrogen peroxide-based fuel cells.

A new model to predict the small-hole decompression process of long CO2 pipeline

CO2 pipeline transportation is considered as an economical and safe way of moving large quantities of CO2 in Carbon Capture Utilization and Storage (CCUS) projects. However, design and planning of CO2 pipelines passing through populated areas require careful risk assessment of accidental pipeline failure scenarios leading to CO2 pipeline decompression. In this study, a new zero-dimensional multi-stage outflow model describing transient decompression of CO2 is developed. The model accounts for the experimentally observed liquid level variation along the pipeline and uses the liquid volume fraction threshold parameter (αt) to mark the end of the saturated liquid flow decompression stage. Besides, the Lee model is applied to describe the mass transfer in gas-liquid phases. The model was validated against experimental data obtained large-scale pipeline decompression tests and can be recommended for simulation of outflow of supercritical and liquid CO2 from pipelines longer than 258 m and the orifice-to-pipeline diameter ratios smaller than 0.21. The advantage of this model lies in its use of the relatively simple Vessel Blowdown Model (VBM) to accurately model the depressurization process. It addresses the inconvenience posed by the heavy computational burden of high-dimensional models when predicting long-duration leakages in large-capacity pipelines.

Condition for metal fragmentation during Earth-forming collisions

The long-term evolution of the deep Earth depends on its initial temperature and composition. These were set by the large planetary collisions that formed the Earth. After each collision, the metallic core of the impactor fell into a molten silicate magma ocean. Previous investigations showed that, as it sank, the impactor core fragmented into drops. The overall fragmentation of the core controlled the efficiency of chemical transfers between the impactor metal and the magma ocean, and, as a consequence, the composition of the Earth's core and mantle. However, because previous studies lack an impact stage, it is unclear whether the projectile core fragmented during the impact at Earth's surface, or deeper in the magma ocean.To answer this question, we conduct laboratory experiments modeling the collision of differentiated and undifferentiated impactors. In a first series of experiments, we investigate the impact of an undifferentiated centimetric liquid volume, representing the impactor core, onto a lighter immiscible liquid, representing the magma ocean. Our experiments approach the dynamical regime of planetary collisions for which inertia is large compared to surface tension. Varying the velocity and size of the impactor, we determine the conditions under which the impactor fragments into drops. We find that fragmentation occurs when the Froude number, which measures the relative importance of inertia to gravity, is larger than 40, regardless of surface tension. This fragmentation results from the growth of a turbulent Rayleigh-Taylor instability at the interface between the impacting liquid and the target pool. In contrast, when Fr<10, the impactor remains coherent. In a second series of experiments, we use two-phase impactors to show that these results hold for impactors that are differentiated into a core and a mantle.Applied to planet formation, our results suggest that the core of impactors less than 330 km in radius impacting at the escape velocity onto an Earth-sized planet fully fragments into droplets during the impact process, whereas the core of a giant Mars-sized impactor remains coherent. We derive a model for the depth at which the impactor core fragments in the magma ocean as a function of the impactor size and velocity. This model predicts that impactors with a radius less than 800 km fully fragment before reaching the bottom of the magma ocean. For velocities higher than twice the escape speed, some degree of fragmentation is unavoidable for any impactor size.

Stochastic models in the under-resolved simulations of spray formation during high-speed liquid injection

In the under-resolved simulation of the high-speed liquid injection into stagnant air, the attention in subgrid-scale models is focused on events of intense gradients of the velocity in turbulent flow, i.e., on effects of intermittency. Three typical flows are considered—the in-nozzle flow, primary atomization zone, and secondary atomization of spray droplets. In the simulation of the first two flows, the filtered Navier–Stokes equations are forced by stochastic processes with properties which incorporate the statistical physics of fluid acceleration at the high Reynolds number—in this way we update the under-resolved acceleration. In the case of in-nozzle flow, the proposed stochastic subgrid acceleration model is combined with wall-damping function, and the ability in prediction of the velocity statistics is demonstrated. In the simulation of primary atomization, the approach with stochastic subgrid acceleration is combined with the volume of fluid method. This leads to intensification of the interface dynamics, resulting in additional corrugation, with more intense shearing and stretching of liquid structures are observed. Thereby, the experimental profiles of the time-averaged liquid volume fraction distribution for four different axial locations are rather well predicted. The secondary atomization of droplets is simulated by a new stochastic model for the breakup rate along the droplet path. To this end, the breakup rate is expressed as a function of turbulent viscous dissipation which evolves along the droplet path according to the proposed stochastic process. Preliminary assessment performed against the recent experiments shows the correct predictability of this model and its low sensibility to the grid density.

A Review Paper on Paint Spraying Robot

Abstract: Painting interior walls is a frequent construction task that takes a lot of time and work. Robotic painting was introduced to replace human manual activity, improving accuracy, efficiency, and lowering costs. In this study, We present an independent robot that paints walls. robot that uses a cascade lift mechanism to enable it to use a paint sprayer to paint a room's interior walls. The paint sprayer can reach the necessary heights With the assistance of of this mechanism for cascading lifts mechanism. With two degrees of freedom (DOF), The robot moves fluidly in each of the six directions. thanks to the DC powered mecanum wheels mounted down to its foundation. Ultrasonic sensors are used by the robot to measure distance, make adjustments to the walls, and determine if the mister has reached the wall's summit. The robot's mecanum wheels, ultrasonic sensors, and other components are all managed by the master controller. The AC power supply powers the entire system Color is sprayed on to manage the amount of color; sprayers are employed for this purpose. Sprayers need to split liquid into droplets that are the right size, distribute them evenly across the surface, and manage the volume of liquid to prevent overapplication. One major issue thataffects workers everywhere is disease control

IOT based water flow meter using ThingSpeak

The Large scale manufacturing companies are fully automated. Soft Drink Industries and Chemical industries have to constantly measure and quantify the liquids that they are handling during this automation process, and the most common sensor used to measure the flow of a liquid is a Flow Sensor. By using a flow sensor with a microcontroller like NodeMCU, we can calculate the flow rate, and check the volume of liquid that has passed through a pipe, and control it as required. Apart from manufacturing industries, flow sensors can also be found in the agriculture sector, food processing, water management, mining industry, water recycling, coffee machines etc. Further, a water flow sensor will be a good addition to projects like Automatic water dispenser and smart irrigation systems where we need to monitor and control the flow of liquids. In this project, we are going to build a water flow meter using NodeMCU. We will interface the water flow sensor with NodeMCU and LCDI2C, and program it to display the volume of water, which has passed through the valve. For this particular project, we are going to use the YF-S201 water flow sensor, which uses a hall effect to sense the flow rate of the liquid. The measured values are also communicated to the ThingSpeak cloud. The parameters can be monitored remotely form any part of the world. When the volume exceeds the threshold value, Thingspeak will activate the Thingspeak react to send a message to the responsible person with help of the IFTTT applet.

Fire detection and suppression in rooms with different geometries

The paper presents experimental research findings on the integral characteristics of physicochemical processes in the area around a fire at different stages of its development and suppression. The purpose of this study was to determine the characteristics of the operation of fire detectors in rooms of various geometries. The temperatures in different cross sections, as well as the composition of gaseo us products of thermal decomposition and flame combustion of materials were investigated. The study dealt with class A fires involving wood. Mock-ups of rooms with distinctly different geometries were used: a parallelepiped, a rectangular truncated pyramid and a bow-roof (arched) structure. Efficient arrangement of technical equipment (light and gas analysis sensors, heat and smoke detectors, nozzles) was determined to provide early detection of a fire, prompt initiation of suppression and completion of combustion and smoldering. Minimum volumes of a firefighting liquid (water in this case) and spraying times were identified that are necessary and sufficient to suppress combustion. Guidelines were proposed on the arrangement of technical equipment for early fire detection and efficient containment of fire in the shortest time. A mathematical apparatus has been developed that allows predicting the performance of fire detectors and sensors. The research results can be used to evaluate the most effective locations for fire sensors in the design of buildings and structures.

Optimization of the fermentation media and growth conditions of Bacillus velezensis BHZ-29 using a Plackett-Burman design experiment combined with response surface methodology.

Bacillus velezensis occurs extensively in the soil environment. It produces a range of antimicrobial compounds that play an important role in the field of biological control. However, during the actual application process it is often affected by factors such as the medium formulation and fermentation conditions, and therefore biocontrol measures often do not achieve their expected outcomes. In this study, the B. velezensis BHZ-29 strain was used as the research object. The carbon and nitrogen sources, and inorganic salts that affect the number of viable bacteria and antibacterial potency of B. velezensis BHZ-29, were screened by a single factor test. A Plackett-Burman design experiment was conducted to determine the significant factors affecting the number of viable bacteria and antibacterial potency, and a Box-Behnken design experiment was used to obtain the optimal growth of B. velezensis BHZ-29. The medium formula that produced the highest number of viable bacteria and most antibacterial substances was determined. The initial pH, temperature, amount of inoculant, liquid volume, shaking speed, and culture time were determined by a single factor test. The factors that had a significant influence on the number of viable bacteria of B. velezensis BHZ-29 were selected by an orthogonal test. A Box-Behnken design experiment was conducted to obtain the optimal fermentation conditions, and highest number of viable bacteria and antibacterial titer. Molasses, peptone, and magnesium sulfate had significant effects on the viable count and antibacterial titer of B. velezensis BHZ-29. The viable count of B. velezensis BHZ-29 increased from 7.83 × 109 to 2.17 × 1010 CFU/mL, and the antibacterial titer increased from 111.67 to 153.13 mm/mL when the optimal media were used. The optimal fermentation conditions for B. velezensis BHZ-29 were as follows: temperature 25.57°C, pH 7.23, culture time 95.90 h, rotation speed 160 rpm, amount of inoculant 2%, and liquid volume 100 ml. After the optimization of fermentation conditions, the number of viable bacteria increased to 3.39 × 1010 CFU/mL, and the bacteriostatic titer increased to 158.85 mm/ml.The plant height and leaf number of cotton plants treated with BHZ-29 fermentation broth were higher than those of cotton inoculated with Verticillium dahliae. The number of bacteria was 1.15 × 107 CFU/g, and the number of fungi was 1.60 × 105 spores/g. The disease index of the cotton seedlings treated with the optimized fermentation broth was 2.2, and a control effect of 93.8% was achieved. B. velezensis BHZ-29 could reduce the disease index of cotton Verticillium wilt and had a controlling effect on the disease. The best effect was achieved in the treatment group with an inoculation concentration of 2 × 108 CFU/ml, the disease index was 14.50, and a control effect of 84.18% was achieved. The fermentation process parameters of the number of viable bacteria and antibacterial titer by strain B. velezensis BHZ-29 were optimized to lay a foundation for the practical production and application of strain B. velezensis BHZ-29 in agriculture.

Propagation of a viscous gravity current beneath a granular mush

The two-dimensional gravity-driven motion of a relatively dense viscous liquid at the base of a granular mush is investigated using a model that exploits the relative shallowness of the flow. The granular mush obeys a $\mu (I)$ -rheology, and we assume that the two phases are segregated throughout the motion. The viscous liquid spreads under gravity, carrying the granular mush above and transporting it outwards as levees at either end of the flow. The accumulation of granular material away from the centre of the deposit produces hydrostatic pressure gradients that retard the viscous gravity current. At later times, the granular mush is quasi-static relative to the moving liquid owing to the balance of outward granular transfer by the liquid and inward hydrostatic pressure gradients associated with the granular free surface. The viscous liquid exhibits a Poiseuille-like flow structure with negligible velocity at both the base and the granular interface. The flow of a fixed volume of viscous liquid becomes self-similar with the effective viscosity quadrupled relative to a classical viscous gravity current owing to the retarding effects of the granular mush. The case of constant input flux of viscous liquid is also analysed. The qualitative features are akin to the fixed volume case with the granular mush forming levees and slowing the viscous spreading. The case in which the upper medium is a Bingham material rather than a granular mush is also discussed, and the same features are observed, demonstrating the importance of the yield criterion in the upper medium.

Droplet impact onto a porous substrate: a Wagner theory for early-stage spreading

An analytical model for droplet impact onto a porous substrate is presented, based on Wagner theory. An idealised substrate boundary condition is introduced, mimicking the effect of fluid entry into a genuinely porous substrate. The asymptotic analysis yields a solution for a small porous correction with free-surfaces and pressures compared with the impermeable case. On a global scale, it is found that the impact region on the substrate grows more slowly with porosity included due to loss of mass into the substrate. The spatial distribution of liquid volume flux into the substrate is also described. Locally near the turn-over regions, the expected jetting along the surface is calculated with the same volume flux but the jet is found to be slower and thicker than for an impermeable substrate.

Adverse respiratory patterns in near-term spontaneously breathing newborn lambs with elevated airway liquid volumes at birth.

Recent evidence indicates that respiratory distress (RD) in near-term infants is caused by elevated airway liquid (EL) volume at the beginning of air-breathing after birth. While the adverse effects EL volumes on newborn lung function are known, the effects on respiratory control and breathing patterns shortly after birth (<4 h) are unknown. We investigated the effects of EL volumes on cardiorespiratory function and breathing patterns in spontaneously breathing near-term newborn lambs in the first hours after birth. At 137-8 days gestation (2-3 days prior to delivery; term ∼147 days), sterile surgery was performed on fetal sheep (n = 17) to implant catheters and blood flow probes. At 140 days, lambs were delivered via caesarean section under spinal anaesthesia. Airway liquid volumes were adjusted to mimic the level expected following vaginal delivery (∼10 ml/kg; Controls; n = 7), or elective caesarean section (∼30 ml/kg; elevated airway liquid group; EL; n = 10). Spontaneous breathing and cardiorespiratory parameters were recorded over four hours after birth. Non-invasive respiratory support with supplemental oxygen was provided if required. EL lambs required higher inspired oxygen levels (p = 0.0002), were less active (p = 0.026), fed less (p = 0.008) and had higher respiratory morbidity scores than Controls (p < 0.0001). EL lambs also displayed higher rates of breathing patterns associated with RD, such as expiratory braking and tachypnoea. These patterns were particularly evident in male EL lambs who displayed higher levels of severe respiratory morbidity (e.g., expiratory braking) than female EL lambs. The study demonstrates that EL volumes at birth trigger respiratory behaviour and breathing patterns that resemble clinically recognised features of RD in term infants.

Extremely large water droplet impact onto a deep liquid pool.

Most studies of droplet impact on liquid pools focus on droplet diameters up to the capillary length (0.27cm). We break from convention and study extremely large water droplets (1 to 6cm diameter) falling into a pool of water. We demonstrate that the depth and width of the cavity formed by large droplet impact is greatly influenced by the deformed shape of the droplet at impact (i.e., prolate, spherical, and oblate), and larger droplets amplify this behavior by flattening before impact. In particular, the maximum cavity depth is a function of the Froude number and axis ratio of the droplet just before impact. Further, the cavity depth is more dependent on the droplet height than width, and the maximum cavity diameter is independent of the droplet height. In general, we observe that more oblate droplets result in decreasing cavity depths for a fixed liquid volume. This is because an increase in horizontal droplet diameter results in a reduced impact energy flux and therefore reduced cavity depth.

Spray formation and spray-wall-flow interaction in a gasoline direct-injection (GDI) engine under early-injection conditions: A flow bench study

The work presented in this study aims to understand the spray-wall-flow interaction within a gasoline direct-injection (GDI) engine flow bench under simulated early-injection conditions. The Engine Combustion Network (ECN) Spray G injector is installed in the Darmstadt optically accessible engine flow bench. Under simulated early-injection conditions, the formation of a multi-hole spray and the interaction with characteristic intake flows, such as the intake jet and central tumble flow, are extensively discussed. By reducing the complexity in the number of variables inherent in engine flow and whole-engine simulation, an engine flow bench operating under various mass flow rates is applied in this study. The numerical simulation is carried out using Large Eddy Simulation (LES) under the Eulerian-Lagrangian framework for spray simulation. Experimental data, acquired through particle image velocimetry (PIV) measurements, provides 2-D flow fields on both the central tumble and valve planes, facilitating the validation of in-cylinder flow fields. Furthermore, experimental data obtained through Mie scattering is utilized to investigate spray formation and evolution within the GDI engine, providing the liquid penetration length and liquid spray angle. Comparison between the numerical and experimental data demonstrates several agreements. Moreover, the variation of different spray plumes under different mass flow rates is observed in the case of both experimental and numerical data. Increasing the mass flow rate distorts the overall plume shape and shifts it away from the intake port. This phenomenon is examined by extracting the liquid volume fraction and vapor fields of each plume. Spray plumes encounter different convective disturbances and evaporation due to their local characteristic in-cylinder flow. Furthermore, spray-wall-flow interaction and wall film deposits are observed during the injection. Lastly, the influence of the spray-induced turbulence is analyzed under different mass flow rates.

Profiles of Static Liquid-Gas Interfaces in Axisymmetric Containers with Different Accelerations.

Second-order perturbation solutions of profiles of bubbles suspended in liquid and liquid-gas interfaces when liquid all sinks in the bottom with different accelerations are derived. Six procedures are developed based on these solutions, and they are divided into two types. One type takes the coordinates of end points of profiles as input, and the other type takes liquid volume or gas volume as input. Numerical simulations are performed with the Volume of Fluid method, and numerical results are in good agreement with the predictions of these procedures. The greater the acceleration, the flatter the bubble until all liquid sinks to the bottom. Effects of acceleration on bubble shape must be considered; otherwise, it will cause a volume prediction error of up to 10%. When all liquid sinks to the bottom, predictions of liquid volume with the same liquid meniscus height as inputs differ considerably for different accelerations. The most significant change in liquid volume occurs when the bond number Bo ≪ 1. Effects of acceleration and liquid contact angle on the liquid-gas interfaces must be considered when evaluating liquid residue. These findings should be quite helpful for liquid residue measurement and fine management in spacecraft.

A parametric study on the effect of liquid water content and droplet median volume diameter on the ice distribution and anti-icing heat estimation of a wind turbine airfoil

This study uses an icing model, combining heat transfer with fluid flow and considering the roughness effect, to investigate the influence of liquid water content (LWC) and droplet median volume diameter (MVD) on the ice distribution and anti-icing heat estimation of a wind turbine blade airfoil through the numerical approach. The findings indicate that the simulated ice distribution can have excellent agreement with experimental data. Owing to variations of droplet collection efficiency and heat flux, the increase in LWC and MVD will amplify the fluctuations in ice accretion distribution, which will be prone to ice horns. Owing to high LWC increasing water film flow range, the jumping point of anti-icing heat flux is closer to the trailing edge. Owing to large MVD increasing droplet collection efficiency, the quantity of ice accumulation through solidification ascends to demand higher anti-icing heat flux. The peak anti-icing heat flux is more evidently influenced by LWC than that by MVD, due to the variations in heat flux, induced by water film evaporation and solidification. The findings offer valuable insights into the flow and heat transfer physics for wind turbine anti/de-icing design.

Physical properties of Radiation Dense Reactive Sintered Borides

Reactive Sintered Borides (RSBs) were fabricated to investigate the effects of carbon and chromium content producing a series of samples referred to as Gen 2 RSBs. These RSBs were tested and evaluated for various mechanical (bulk moduli, fracture toughness, nano and micro-hardness) and microstructural properties. It is the first time when the correlation between different RSB phases and mechanical properties are understood in detail, along with the CALPHAD assessment of RSBs. CALPHAD was used to investigate the effect of sintering pressure and composition on melting point and liquid volume at sintering temperature and was critical in understanding of phase differences in Gen 1 and Gen 2 RSBs. Effects of carbon and chromium addition on mechanical and microstructural properties of RSBs were also investigated. Optimal second generation RSBs have fracture toughness of 7-10.1 MPa m0.5 and hardness of 15.9-19.1 GPa. RSBs with relative sintered density > 98% were achieved in this work. Combined X-ray diffraction and EBSD-EDX techniques were used to determine and confirm phase presence in RSBs. This work has demonstrated tractability and reproducibility of RSB materials with suitable mechanical properties for potential applications in spherical tokamaks alongside existing cemented tungsten carbides.