Heating Power Research Articles

Thermal energy storage using phase change material for solar thermal technologies: A sustainable and efficient approach

Over-exploitation of fossil-based energy sources is majorly responsible for greenhouse gas emissions which causes global warming and climate change. To mitigate these challenges renewable energy sources, especially solar thermal technologies, can play a decisive role. United Nations also proposes steps to attenuate the adverse effects of fossil-based energy and climate change through Sustainable Development Goals (SDG7 and SDG8). Solar thermal technologies have seen a huge capacity expansion around the globe in previous decades because of their inherent advantages. However, solar energy faces crucial limitations of fluctuating intensity and time-dependent availability. This decreases solar thermal system performance and makes solar thermal technologies time-dependent. To overcome these challenges, integrating phase change material (PCM) in solar thermal technologies makes a sustainable approach to enhance the efficacy, productivity, and utilization rate of solar thermal technologies. In this manuscript, the sustainable approach of integrating PCM in solar thermal technologies was reviewed. This includes literature on PCMs which covers classification, properties, importance, and limitation. Comprehensive data on the integration of PCM with solar thermal technologies such as solar water heating, solar desalination, solar cooking, solar dryers, solar PV/T, solar ponds, solar chimneys, and solar power plants were reported explicitly in terms of the type of PCM, efficiency and their productivity. In addition, the effect of PCMs integration in solar thermal technologies was analyzed in terms of mitigation of CO2 emissions and economic analysis at different locations around the World.

Optically manipulated nitrate-salt-based direct absorption solar collectors for a photothermal energy harvesting system

This study introduces a nitrate-salt-based direct absorption solar collector (DASC) for a photothermal energy harvesting system with efficient solar energy harvesting and the reduction of thermal radiation loss. Investigations of the optical properties of snow-like solid-state binary nitrate salt in solar and thermal infrared (IR) spectral regions were first conducted in this study. Research revealed that the solid-state binary nitrate salt showcases high solar reflectivity (>90 %) and infrared emissivity (∼0.85), leading to a cooling power of 36.4 W m−2. This implies pure solid salt cannot gain energy from solar illumination. To tackle this, the proposed system incorporated nano graphite and a hot mirror. Consequently, the absorbed solar energy increased from 67.6 W m−2 to 898.7 W m−2, resulting in a heating power of 794.0 W m−2 under AM 1.5G solar irradiance. With the proposed approaches, melting the salt with lowest solar concentration ratio of 15 (∼12.5 kW m−2) was achieved.

Rod bundle cooling by a spray system in spent fuel pool accident conditions

The knowledge of the phenomenology of loss of coolant/cooling scenarios in spent fuel pools is of prime interest since a huge amount of fission product can be released in accident conditions. In this context, the ASPIC facility is dedicated to the study of the heat transfers that occur at the scale of one rod bundle stored in a spent fuel pool cell. Investigations have been carried out on a full high assembly composed of 17 × 17 electrically heated rods. The water level in the cell is controlled and set, in this test series, so that about one meter of the assembly is uncovered. Therefore, the upper part of the assembly gets overheated unless some counter measure is undertaken. In this contribution, the ability of a spray system to limit the temperature rise of the uncovered part of the rod bundle is assessed. It has been observed that the water spray reduces the temperature level on the whole cross section of the assembly and lowers significantly the risk of degradation of the rod bundle. Besides, for a bundle heat power of 20kW, a spray mass flow rate of 10 gs−1 or higher leads to rod temperatures lower than 480°C.

Experimental study of an aluminum based three-dimensional thermosyphon heat sink with microscale enhancement structure

One of the most significant limitations to the advancement of electronics is the issue of heat dissipation. Currently, air cooling remains the most widely used method for heat dissipation due to the advantages of low cost and ease of maintenance. However, the traditional air-cooling method based on an all-solid heat sink is unable to keep pace with the rapid advancement in thermal power of electronics due to its limitation in area expansion by only solid fins. This study proposes an aluminum-based three-dimensional thermosyphon (3D-TS) coupling boiling-condensation heat transfer and forced air cooling as a means of overcoming the limitations of conventional air-cooling methods. Additionally, the incorporation of micro pin-fins enhances the boiling heat transfer and the overall performance of the three-dimensional thermosyphon. The performance of the three-dimensional thermosyphon is experimentally studied and analyzed under different volumetric flow rates using the environmentally friendly refrigerant R1233zd(E) as the working fluid. The results indicate that the total thermal resistance exhibits a biphasic response to heating power, with a decrease initially followed by an increase. This response is primarily attributed to the boiling mode on the substrate. Moreover, the micro pin-fins significantly enhance the boiling heat transfer on the substrate of the three-dimensional thermosyphon, enabling the three-dimensional thermosyphon to reach a minimum thermal resistance of 0.075 K/W and a maximum thermal dissipating power of 650 W with the temperature of the heating source below 85 °C. The three-dimensional thermosyphon proposed in this work is capable of meeting the cooling requirements of the majority of high-performance chips. This paper offers a valuable reference and guidance for the design and optimization of the phase-change devices.

Performance study of an electrified temperature vacuum swing adsorption cycle for post combustion carbon capture

The performance of a fully electrified temperature vacuum swing adsorption (E-TVSA) carbon capture process is investigated and compared with the performance of a VSA cycle as the reference case. A five-step process including (I) adsorption, (II) co-current heating, (III) counter-current evacuation, (IV) counter-current pressurizing, and (V) co-current closed loop cooling steps was devised and simulated. The adsorption time, electric heating power, and evacuation pressure were chosen as the independent variables for evaluating their impact on key performing indicators (KPI) of purity, recovery, productivity and energy consumption. In total 2717 cases were simulated to the cyclic steady state condition to provide 44 contours of the KPIs. From these contours it can be concluded that in E-TVSA carbon capture using 13X zeolite, a temperature rise of almost 50 degrees is necessary during the heating step, and the evacuation step should be continued to reach a pressure between 2.5 and 3 kPa. Under these conditions, a recovery and purity of more than 98 % were achieved with a production rate above 1.1 kg CO2/kg ads day and a specific energy consumption of 1.74 MJ/kg CO2 (0.61 MJ/kg CO2 for evacuation and 1.13 MJ/kg CO2 for heating). When comparing E-TVSA and VSA, it is noteworthy that the production rate and specific energy consumption of E-TVSA are in the same order as that of VSA. However, E-TVSA surpasses VSA in terms of purity and recovery rates. Further analysis of the transformation efficiency from electricity to heat revealed the transformation efficiency must be at least 50 % to keep the energy consumption below 3 MJ/kg CO2.

Negative triangularity scenarios: from TCV and AUG experiments to DTT predictions

Abstract Experiments, gyrokinetic simulations and transport predictions were performed to investigate if a negative triangularity (NT) L-mode option for the Divertor Tokamak Test (DTT) full-power scenario would perform similarly to the positive triangularity (PT) H-mode reference scenario, avoiding the harmful edge localized modes (ELMs). The simulations show that a beneficial effect of NT coming from the edge/scrape-off layer (SOL) region ρ tor > 0.9 is needed to allow the actual NT L-mode option to perform like the PT H-mode. Dedicated experiments at TCV and AUG, with DTT-like shapes, show an optimistic picture. In TCV, experiments indicate that even with the relatively small triangularity of the DTT NT scenario, a large beneficial effect of NT comes from the plasma edge and SOL, allowing NT L-modes to outperform PT L-modes with the same power input, reaching the same central pressures as PT H-modes with twice as much applied heating power. For AUG, NT plasmas go into H-mode more easily than for TCV, but always present much smaller pedestals compared with PT plasmas with the same input power, showing a much weaker or absent ELM activity. However, NT has a smaller beneficial effect for AUG than for TCV, with NT pulses outperforming PT pulses with the same input power only for an ECRH-only case with relatively low input power. For the considered AUG cases, PT pulses perform better than NT ones at higher ECRH power or with mixed NBI and ECRH power. Based on this analysis, the NT option is a viable alternative for the DTT full power scenario, providing high performance plasmas with reduced or absent ELMs.

Experimental investigation on the thermal performance of a large-size aluminum vapor chamber for multi-point heat sources

Abstract With the development of electronic information technology, the integration and power of electronic equipment continue to increase. As an efficient heat transfer element, vapor chambers are widely used in the field of heat dissipation of electronic devices. However, greater challenges have been posed in terms of higher heat dissipation capacity, larger size, and lighter weight. Therefore, a large-scale aluminum vapor chamber with a size of 340 mm×295 mm ×7.5 mm is designed for the heat dissipation of multi-point array heat sources. Multiple parallel porous ribs are sintered to form capillary wicking channels and vapor diffusion paths, which efficiently transfer the heat from the middle of the vapor chamber to the cold plate on the two sides. The transient working characteristics and heat dissipation performance under different working conditions are experimentally investigated. The results show that there is obvious temperature instability, which can be suppressed by the tilt of the vapor chamber and the increase of the heating power. Under the tilt condition, the temperature rises in the vertical direction due to the influence of gravity, while the inclination angle has basically no effect. The vapor chamber can work stably at the total heating power of 2100 W with the smallest thermal resistance 0.03 °C/W. The single-point heat flux can reach 7.3W/cm2 for the 128 heat sources. Compared to a traditional vapor chamber, the proposed aluminum vapor chamber provides a thermal management solution for large-size electronic devices with multiple heat sources.

A non-destructive heating method for lithium-ion batteries at low temperatures

Low temperatures seriously affect the performance of lithium-ion batteries. This study proposes a non-destructive low-temperature bidirectional pulse current (BPC) heating method. Different from existing heating approaches, this method not only optimizes heating frequency and amplitude but also considers the optimization of the charge/discharge pulse duration ratio. To optimize the BPC heating strategy, a precise electro-thermal coupled model is established, and a neural network is employed to delineate the relationship among model parameters, temperature, and state of charge (SOC). Additionally, the interplay between the impedance of the graphite anode and that of the full cell is analyzed by constructing a three-electrode battery. Then, a novel full-cell-oriented lithium plating criterion is introduced. Finally, based on the constructed electro-thermal coupled model, lithium plating criterion, and terminal voltage constraint, a novel non-destructive BPC heating method is proposed. The results show a significant improvement in heating efficiency compared to conventional BPC heating. Especially for high SOCs, the heating power is increased at least 8 times. When the battery SOC is below 40 %, the average heating rate from −10 °C to 10 °C is 11.28 °C/min. Even at 90 % SOC, the heating rate remains at 2.88 °C/min. Furthermore, the capacity and impedance of a battery at 50 % SOC exhibit no significant changes after 60 heating cycles using the optimal BPC heating strategy at 100 Hz. These findings show that the optimized method proposed in this study has high heating efficiency and no damage to the battery.

Study of the eddy currents effect in Spinning rotor Gauge

The Spinning Rotor Gauge (SRG) serves as a crucial tool in metrology as a secondary standard vacuum gauge. However, its lower measurement limit is not solely determined by background gas molecular friction damping but is also affected by other contributing factors, collectively termed residual damping. This paper investigates the influence of eddy currents on residual damping. It quantitatively analyzes the electromagnetic torque and eddy current heating power induced within the rotor’s interior and surface, calculates the corresponding kinetic energy loss, and simulates the rotor’s attenuation. The simulation predicts an attenuation of 0.23 Hz within a 12-hour period, corresponding to an average background pressure of 7 × 10-5 Pa. A comparison with observed residual damping data, showing an attenuation of 1.17 Hz and a background pressure of 1.6308 × 10-4 Pa, demonstrates high consistency. This affirms the reliability of the numerical model and calculation results regarding eddy current-induced residual damping presented in this article.

Impact of fuel dilution on Lawson parameter by considering relativistic correction of radiation loss in toroidal magnetic configuration

In this paper, the ignition boundary and height of the saddle point as the lowest heating power on the way to ignition for D-3He toroidal magnetic configuration are derived. Fusion fuel cycle involving deuterium and helium-3, along with side reactions is considered. The effect of fuel dilution, incorporating synchrotron radiation and bremsstrahlung power loss with relativistic correction on ignition criteria, is investigated. The results were compared by considering the classical state of bremsstrahlung power. It is found that the height of the saddle point is increased with increasing the ratio of the proton particle density to the fuel deuteron density. The ignition regime shrinks and the minimum value of the Lawson parameter for the breakeven condition and ignition boundaries is reduced due to fuel dilution.

The impact of varying cold end diameter on the energy separation in Ranque-Hilsch vortex tube for different working gases: A CFD simulation and thermodynamic analysis

The vortex tube is a potential candidate for sustainable cooling due to its unique feature of energy separation without using any synthetic refrigerant. However, the investigation of energy separation and performance optimization always has been challenging due to its complex physics. In previous literature, the performance of vortex tube has been found affected by several parameters. In order to find the impact of varying cold end diameters with different gases, this paper investigates temperature separation in seven vortex tubes of different cold end diameters operating with three different working gases: He, N2, and CO2. A detailed thermodynamic analysis of their thermal separation performances at different cold mass fractions is presented for each working gas. Exergy analysis has also been conducted and discussed separately. As a result of this extensive investigation, it is found that the larger cold end diameter improves the performance of the vortex tube. The cold and hot temperature separation, cooling, and heating power at higher cold mass fractions are found to improve when operated with helium compared to other gas. However, the COP of cooling and COP of heating at higher cold mass fractions is found to be lower with helium. Improvements in the physical and kinetic exergies at the inlet and both outlets are observed with increasing cold end diameter, except for the kinetic exergy at the hot outlet. Helium gas is found to show more exergy at the inlet and both outlets among all three gases. The performance of vortex tube operating at higher cold mass fraction shows an improvement in exergies at outlets, except kinetic exergies at hot outlet. The total exergy efficiency decreases at cold outlet on increasing cold end diameter. However, the results of actual (physical) exergy efficiency shows an improvement at both outlet for larger cold end diameter. The actual exergy efficiency is calculated by considering the physical exergy alone because the kinetic exergy completely lost into the open atmosphere. Physical exergy efficiency at hot outlet is also found to increase on increasing cold mass fraction, while it decreases at cold outlet. Physical exergy efficiency of cooling and heating are found to more when operated with helium compared to nitrogen and carbon dioxide.

Model-Based Optimization of Solid-Supported Micro-Hotplates for Microfluidic Cryofixation.

Cryofixation by ultra-rapid freezing is widely regarded as the gold standard for preserving cell structure without artefacts for electron microscopy. However, conventional cryofixation technologies are not compatible with live imaging, making it difficult to capture dynamic cellular processes at a precise time. To overcome this limitation, we recently introduced a new technology, called microfluidic cryofixation. The principle is based on micro-hotplates counter-cooled with liquid nitrogen. While the power is on, the sample inside a foil-embedded microchannel on top of the micro-hotplate is kept warm. When the heater is turned off, the thermal energy is drained rapidly and the sample freezes. While this principle has been demonstrated experimentally with small samples (<0.5 mm2), there is an important trade-off between the attainable cooling rate, sample size, and heater power. Here, we elucidate these connections by theoretical modeling and by measurements. Our findings show that cooling rates of 106 K s-1, which are required for the vitrification of pure water, can theoretically be attained in samples up to ∼1 mm wide and 5 μm thick by using diamond substrates. If a heat sink made of silicon or copper is used, the maximum thickness for the same cooling rate is reduced to ∼3 μm. Importantly, cooling rates of 104 K s-1 to 105 K s-1 can theoretically be attained for samples of arbitrary area. Such rates are sufficient for many real biological samples due to the natural cryoprotective effect of the cytosol. Thus, we expect that the vitrification of millimeter-scale specimens with thicknesses in the 10 μm range should be possible using micro-hotplate-based microfluidic cryofixation technology.

Experimental study on the cold-start performance of a gas heating assisted air-cooled proton exchange membrane fuel cell stack

Air-cooled proton exchange membrane fuel cells (PEMFCs) have the advantages of simple structure, low parasitic power, and flexible application scenarios. However, it is difficult to warm up the stack under subzero temperatures because excessive air is used as the cooling medium. In this study, the thermal balance inside an air-cooled PEMFC stack during cold start was theoretically analyzed to explore the relationship between the heating power and ambient temperature. Subsequently, the cold-start performance was tested in a climatic chamber. The results showed that the combination of endplate heating and gas heating is a feasible cold-start measure. The theoretical analysis indicated that only 14 % of the stack rated power for preheating can promote a successful cold start at −30 °C, which has also been validated in the ensuing tests. The test results showed that the temperature uniformity and the cell voltage consistency deteriorate as the ambient temperature decreases, while these two indicators can be improved by increasing the gas heating power. As the ambient temperature decreases, the heating power may become too high, resulting in poor cold-start performance. Therefore, if an air-cooled stack is to be started at extreme low temperatures, further research is needed in terms of flow fields and materials.

Flexible boron nitride-based composite membrane with superhydrophobic/electrothermal synergistic response for enhanced passive anti-icing and active de-icing

Ice crystals and snow adhesion can affect the operation and reliability of machines in cold, snowy conditions, so anti-freeze systems are often installed in machines. Commonly used ice protection systems usually place electrothermal and a hydrophobic layer in one layer, or create a hydrophobic layer at top of the electrothermal layer. However, the hydrophobic layer ruptures and there is a risk of a short circuit when water comes into contact with the electrically heated layer. In this paper, a method of using boron nitride film to separate the functional layer is proposed to reduce the risk of short circuit in the electric heating layer. Finally, boron nitride film is successfully used as the intermediate layer to connect the superhydrophobic layer with the electric heating layer, which realizes the passive. The results show that the contact angle of the BN-based composite membrane can reach more than 160°. Under the heating power of 0.54 W/cm2, the BN-based composite membrane can reach the steady state temperature of 82.6 °C in 6 min, the deicing efficiency can reach 15.435 kg h−1 m−2, and the removal of 6 mm thick melting ice takes only 185 s. In addition, after 10 electric heating cycles, the BN-based composite membrane can still maintain a temperature of about 80 °C, indicating that it has good durability. This study is of great significance for practical ice control applications.

Overview of the recent experimental research on the J-TEXT tokamak

The J-TEXT capability is enhanced compared to two years ago with several upgrades of its diagnostics and the increase of electron cyclotron resonance heating (ECRH) power to 1 MW. With the application of electron cyclotron wave (ECW), the ECW assisted plasma startup is achieved; the tearing mode is suppressed; the toroidal injection of 300 kW ECW drives around 24 kA current; fast electrons are generated with toroidal injected ECW and the runaway current conversion efficiency increases with ECRH power. The mode coupling between 2/1 and 3/1 modes are extensively studied. The coupled 2/1 and 3/1 modes usually lead to major disruption. Their coupling can be either suppressed or avoided by external resonant magnetic perturbation fields and hence avoids the major disruption. It is also found that the 2/1 threshold of external field is significantly reduced by a pre-excited 3/1 mode, which can be either a locked island or an external kink mode. The disruption control is studied by developing prediction methods capable of cross tokamak application and by new mitigation methods, such as the biased electrode or electromagnetic pellet injector. The high-density operation and related disruptions are studied from various aspects. Approaching the density limit, the collapse of the edge shear layer is observed and such collapse can be prevented by applying edge biasing, leading to an increased density limit. The density limit is also observed to increase, if the plasma is operated in the poloidal divertor configuration or the plasma purity is increased by increasing the pre-filled gas pressure or ECRH power during the start-up phase.

Effects of hydrogen volume fraction, air fuel ratio, and compression ratio on combustion and emission characteristics of an SI ammonia-hydrogen engine

An effective approach to reducing greenhouse gas emissions is to utilize low/zero carbon fuels. This study simulated the combustion of a marine spark ignition (SI) ammonia-hydrogen engine, focusing on the effects of hydrogen volume fraction (XH2), air fuel ratio (λ), and compression ratio (CR) on the combustion and emission characteristics. The pathways of nitrogen-based pollutants such as NH3, NO, and N2O were explained. The results show that increasing XH2 improves Pmax, heat release rate, thermal efficiency, and power. Regarding emission characteristics, when XH2 rises, NH3 emissions drop; NOx emissions remain almost constant at λ ≤ 1 (2100 ppm at λ = 1) and considerably increase at λ > 1, peaking at 5245 ppm. Moreover, as CR rises, the engine power and thermal efficiency increase, NOx emissions decrease by 10%, and N2O emissions are below 20 ppm. Furthermore, chemical kinetic analysis shows that NO comes from N and N2, diffuses from the flame front toward the center in the cylinder under λ = 1.2. And NO comes from HNO and is generated in the flame front and the center under λ = 0.9, respectively. N2O is produced by NH and NH2 and is only generated in the flame front.

Assessments of the key plasma parameters with different scenarios on HIT-PSI using EMC3-EIRENE

Linear plasma devices offer an effective way to conduct plasma-wall interaction studies and contribute to a basic understanding of edge plasma physics. A new platform at Harbin Institute of Technology for Plasma Surface Interaction experiments (HIT-PSI) is a newly-built linear device at the stage of commissioning that is capable of simulating high heat power deposition on divertor targets similar to tokamak conditions. Therefore, numerical simulations to evaluate the plasma characteristics are essential for designing and guiding the experimental conditions in HIT-PSI. In this work, the three-dimensional edge transport code EMC3-EIRENE has been used to investigate the plasma parameter distributions in HIT-PSI with the puffing and pumping systems involved. The effects of the heating power and target position on the distribution of electron density, electron temperature, and particle and heat fluxes have been investigated by EMC3-EIRENE. Particularly, the reduction in the electron density with the puffing fluxes has also been studied by analyzing individual atomic and molecular processes. Finally, the influence of varying pumping speeds on plasma parameters has been investigated in detail by adjusting the recycling coefficients at the two pumping ports.

Semisynthetic ferritin-based nanoparticles with high magnetic anisotropy for spatial magnetic manipulation and inductive heating.

The human iron storage protein ferritin represents an appealing template to obtain a semisynthetic magnetic nanoparticle (MNP) for spatial manipulation or inductive heating applications on a nanoscale. Ferritin consists of a protein cage of well-defined size (12 nm), which is genetically modifiable and biocompatible, and into which a magnetic core is synthesised. Here, we probed the magnetic response and hence the MNP's suitability for (bio-)nanotechnological or nanomedical applications when the core is doped with 7% cobalt or 7% zinc in comparison with the undoped iron oxide MNP. The samples exhibit almost identical core and hydrodynamic sizes, along with their tunable magnetic core characteristics as verified by structural and magnetic characterisation. Cobalt doping significantly increased the MNP's anisotropy and hence the heating power in comparison with other magnetic cores with potential application as a mild heat mediator. Spatial magnetic manipulation was performed with MNPs inside droplets, the cell cytoplasm, or the cell nucleus, where the MNP surface conjugation with mEGFP and poly(ethylene glycol) gave rise to excellent intracellular stability and traceability within the complex biological environment. A magnetic stimulus (smaller than fN forces) results in the quick and reversible redistribution of the MNPs. The obtained data suggest that semisynthetic ferritin MNPs are highly versatile nanoagents and promising candidates for theranostic or (bio-)nanotechnological applications.

Overview of the first Wendelstein 7-X long pulse campaign with fully water-cooled plasma facing components

After a long device enhancement phase, scientific operation resumed in 2022. The main new device components are the water cooling of all plasma facing components and the new water-cooled high heat flux divertor units. Water cooling allowed for the first long-pulse operation campaign. A maximum discharge length of 8 min was achieved with a total heating energy of 1.3 GJ. Safe divertor operation was demonstrated in attached and detached mode. Stable detachment is readily achieved in some magnetic configurations but requires impurity seeding in configurations with small magnetic pitch angle within the edge islands. Progress was made in the characterization of transport mechanisms across edge magnetic islands: Measurement of the potential distribution and flow pattern reveals that the islands are associated with a strong poloidal drift, which leads to rapid convection of energy and particles from the last closed flux surface into the scrape-off layer. Using the upgraded plasma heating systems, advanced heating scenarios were developed, which provide improved energy confinement comparable to the scenario, in which the record triple product for stellarators was achieved in the previous operation campaign. However, a magnetic configuration-dependent critical heating power limit of the electron cyclotron resonance heating was observed. Exceeding the respective power limit leads to a degradation of the confinement.

NSTX-U research advancing the physics of spherical tokamaks

The objectives of NSTX-U research are to reinforce the advantages of STs while addressing the challenges. To extend confinement physics of low-A, high beta plasmas to lower collisionality levels, understanding of the transport mechanisms that set confinement performance and pedestal profiles is being advanced through gyrokinetic simulations, reduced model development, and comparison to NSTX experiment, as well as improved simulation of RF heating. To develop stable non-inductive scenarios needed for steady-state operation, various performance-limiting modes of instability were studied, including MHD, tearing modes, and energetic particle instabilities. Predictive tools were developed, covering disruptions, runaway electrons, equilibrium reconstruction, and control tools. To develop power and particle handling techniques to optimize plasma exhaust in high performance scenarios, innovative lithium-based solutions are being developed to handle the very high heat flux levels that the increased heating power and compact geometry of NSTX-U will produce, and will be seen in future STs. Predictive capabilities accounting for plasma phenomena, like edge harmonic oscillations, ELMs, and blobs, are being tested and improved. In these ways, NSTX-U researchers are advancing the physics understanding of ST plasmas to maximize the benefit that will be gained from further NSTX-U experiments and to increase confidence in projections to future devices.