Metal Support Structures Research Articles

Ultrasound-Driven enhancement of Pt/C catalyst stability in oxygen reduction reaction

Polymer electrolyte membrane fuel cells (PEMFCs) have reached the commercialization phase, representing a promising approach to curbing carbon emissions. However, greater durability of PEMFCs is of paramount importance to ensure their long-term viability and effectiveness, and catalyst development has become a focal point of research. Pt nanoparticles supported on carbon materials (Pt/C) are the primary catalysts used in PEMFCs. Accomplishing both a high dispersion of uniform metal particles on the carbon support and robust adhesion between the metal particles and the carbon support is imperative for superior stability, and will thereby, advance the practical applications of PEMFCs in sustainable energy solutions. Ultrasound-assisted polyol synthesis (UPS) has emerged as a suitable method for synthesizing catalysts with a well-defined metal-support structure, characterized by the high dispersion and uniformity of metal nanoparticles. In this study, we focused on the effect of ultrasound on the synthesis of Pt/C via UPS and the resulting enhanced stability of Pt/C catalysts. Therefore, we compared Pt/C synthesized using a conventional polyol synthesis (Pt/C_P) and Pt/C synthesized via UPS (Pt/C_U) under similar synthesis conditions. The two catalysts had a similar Pt content and the average particle size of the Pt nanoparticles was similar; however, the uniformity and dispersion of Pt nanoparticles in Pt/C_U were better than those of Pt/C_P. Moreover, ex/in-situ analyses performed in a high-temperature environment, in which nanoparticles tend to agglomerate, have revealed that Pt/C_U exhibited a notable improvement in the adhesion of Pt particles to the carbon support compared with that of Pt/C_P. The enhanced adhesion is crucial for maintaining the stability of the catalyst, ultimately contributing to a better durability in practical applications. Ultrasound was applied to the carbon support without the Pt precursor under the same UPS conditions used to synthesize Pt/C_U to identify the reason for the increased adhesion between the Pt particles and the carbon support in Pt/C_U, and we discovered that oxygen functional groups (C-O, C = O, and O-C = O) for anchoring site of Pt particles were generated in the carbon support. Pt/C_U displayed an increase in stability in an electrochemical accelerated stress test (AST) in an acidic electrolyte. The physical and chemical effects of ultrasound on the synthesis of Pt/C via UPS were identified, and we concluded that UPS is suitable for synthesizing carbon supported electrocatalysts with high stability.

Metal-Supported Solid Oxide Cells for Energy Conversion, Electrolysis, and Chemical Synthesis

This talk will provide an overview and update of performance, durability, and applications of metal-supported solid oxide fuel cell (MS-SOFC) and electrolysis cell (MS-SOEC) technology developed at Lawrence Berkeley National Laboratory (LBNL). The unique LBNL symmetric cell architecture design, with thin zirconia ceramic backbones and electrolyte sandwiched between porous metal supports, offers a number of advantages over conventional all-ceramic cells, including low-cost structural materials (e.g. stainless steel), mechanical ruggedness, excellent tolerance to redox cycling, and extremely fast start-up capability. These features enable a wide variety of applications including vehicle range extenders, electrolysis for intermittent renewables, personal power generators, and distributed generation.With infiltrated catalysts, the catalyst compositions can be easily tailored to a variety of reactions, without re-optimizing the entire cell. Recent efforts have developed catalysts for internal reforming of natural gas and ethanol, steam electrolysis to produce hydrogen, oxidative coupling of methane to synthesize ethylene, and oxygen generation from air. A recent focus is 1000+ hour continuous operation with detailed post-mortem analysis. Progress on cell performance and durability for each of these applications will be discussed.Infiltrated catalysts, however, present a tradeoff between initial performance and long-term stability. Extremely high surface area promotes high electrochemical reaction rates, but also provides high surface energy leading to coarsening and facilitates Cr deposition. Recent approaches to mitigating catalyst coarsening and Cr deposition within the cathode include coatings to prevent Cr evaporation from the stainless steel components, and optimization of infiltrated catalyst processing to stabilize the microstructure during operation. The metal support structure has also been optimized for improved mass transport.

Optimization of metal-supported solid oxide electrolysis cells with infiltrated catalysts

Metal-supported solid oxide electrolysis cells (MS-SOECs) are being developed for steam-to-hydrogen electrolysis, especially for utilization of dynamic or intermittent electrical power from renewable sources. Various aspects of the electrocatalyst processing and composition, and metal support structure were explored. Catalyst materials, infiltration temperature and infiltration cycles were optimized for high performance and durability. Numerous catalyst materials were screened for both oxygen and steam electrodes. The oxygen catalyst had moderate impact on both initial cell performance and durability. Reducing Ni content in the steam electrode had little effect on durability, but reduced initial performance. Ex-situ XRD analysis and cell assessment of catalyst infiltration temperature revealed that the optimal range is 750–850 °C. The best cell performance and durability was achieved with LSCF-SDC oxygen electrocatalyst and SDC-Ni (60:40 vol%) steam electrocatalyst infiltrated 11 times at 800 °C and operated at 700 °C. At low steam content, a significant mass transport limitation on the steam side results in limiting current behavior. Thinner and more porous metal supports were implemented, and found to improve steam mass transport at low steam content, relevant for SOECs operating under high H2 recycle rate or high steam utilization.

Low temperature ammonia synthesis by surface protonics over metal supported catalysts.

Low-temperature ammonia synthesis by applying an electric field to a solid heterogeneous catalyst was investigated to realize an on-demand, on-site catalytic process for converting distributed renewable energy into ammonia. By applying an electric field to the catalyst, even at low temperatures, the reaction proceeds efficiently by an "associative mechanism" in which proton-conducting species on the support surface promote the formation of N2Had intermediates through surface protonics. Kinetics, isotope exchange, infrared spectroscopy, X-ray spectroscopy, and AC impedance analysis were performed to clarify the effect of metal and catalyst support structure on the reaction, and an evaluation method for the surface protonics of the support was established to analyze the reaction mechanism, and further analysis using computational chemistry was also conducted. The elementary step determining catalytic activity changed from N2 dissociation to N2H formation, and this difference resulted in high activity for ammonia synthesis at low temperatures even when using base metal catalysts such as Fe and Ni.

Optimization of metal-supported solid oxide fuel cells with a focus on mass transport

Performance of symmetric-architecture metal-supported solid oxide fuel cells was improved significantly by optimizing the catalyst infiltration process and metal support structure. Optimization of component structure and processing parameters was performed during tape-casting and fabrication of button cells. Mass transport of oxygen in the metal support was identified as a major limitation. To overcome this limitation, pore former loading and thickness of the metal support (130–250 μm) were optimized. The catalyst infiltration process was also improved by studying the impact of firing temperature (400 °C–900 °C) and infiltration cycle numbers (1–15). The maximum power density of the optimized cell was 0.9 W cm−2 at 700 °C using hydrogen as a fuel, a three-fold increase over the baseline cell performance. The degradation rate of optimized cells at 550 °C, 600 °C, and 700 °C was 2%, 4.5%, and 5.5% per 100 h, respectively. The phenomena of mass transport, catalyst coarsening, and chromium poisoning on the catalyst were analyzed by electrochemical impedance spectroscopy and scanning electron microscopy.

Practical Aspects of Weight Measurement Using Image Processing Methods in Waterfowl Production

Precision poultry farming technologies include the analysis of images of poultry flocks using cameras. In large-scale waterfowl farming, these can be used to determine the individual weight of poultry flocks. In our research in a real farming environment, we investigated the cameras fixed to the metal support structure of the barn, located above the suspended bird scales. Camera images of the bird on the weighing cell, taken from a top view, were matched to the weight data measured by the scale. The algorithm was trained on training data sets from a part of the database, and the results were validated with the other part of the database (Training: 60% Validation: 20% Testing: 20%). Three data science models were compared, and the random forest method achieved the highest accuracy and reliability. Our results show that the random forest method gave the most reliable results for determining the individual weights of birds. We found that the housing environment had a strong influence on the applicability of the data collection and processing technology. We have presented that by analyzing carefully collected images, it is possible to determine the individual weights of birds and thus provide valuable information on it.

Metal-Supported Solid Oxide Electrolysis Cells with Coatings to Suppress Chromium Migration

High-temperature electrolysis (HTE) is an efficient technology for converting steam to hydrogen. The performance, durability, and applications of metal-supported solid oxide electrolysis cell technology developed at Lawrence Berkeley National Laboratory (LBNL) will be discussed. The unique LBNL symmetric cell architecture design, with thin zirconia ceramic backbones and electrolyte sandwiched between porous metal supports, offers a number of advantages over conventional all-ceramic cells, including low-cost structural materials (e.g. stainless steel), mechanical ruggedness, excellent tolerance to redox cycling, and extremely fast start-up capability.An inherent limitation of this design is the intimate contact between the electrode and the porous stainless steel, which is a source of chromium (Cr). Cr migrates from the support to the electrode during cell fabrication and operation, and reacts with the oxygen evolution electrocatalyst (LSCF). This Cr poisoning reduces performance and durability. To overcome this limitation, Cr-blocking coatings have been applied to the porous stainless steel. A variety of coating compositions and deposition techniques have been evaluated. The best coating dramatically reduces the amount of Cr detected in the electrode both after catalyst infiltration at 800°C and after 1000 h continuous operation at 700°C, Fig 1.Other aspects of the MS-SOEC design and operation have been optimized for performance and durability. These include the infiltrated catalyst composition and processing, metal support structure, and operating temperature. Figure 1

Spontaneous synthesis of silver nanoparticles on cobalt-molybdenum layer double hydroxide nanocages for improved oxygen evolution reaction

Modulating electronic resistance properties and enhancing both active site populations and per-site activity are highly desirable for the application of layered double hydroxides (LDHs) in the electrocatalytic oxygen evolution reaction (OER). Herein, a metal-support structure consisting of silver (Ag) nanoparticles supported by MoO42− intercalated Co-LDH (CoMo-LDH) nanocages (Ag@CoMo-LDH) was developed using a sacrificial template method and a subsequent spontaneous strategy. The resultant hybrid was shown to be a highly efficient OER electrocatalyst in alkaline media. The required overpotential of Ag@CoMo-LDH for affording a geometric current density of 10 mA cm−2 is as low as 205 mV, which is not only significantly lower than that of separate CoMo-LDH or Ag nanoparticles but also superior to that of most developed OER electrocatalysts reported recently. The constituents and respective work mechanism of Ag@CoMo-LDH are discussed in detail. The superior performance of Ag@CoMo-LDH is related to the unique construction and the effective and stable heterointerfaces between Ag nanoparticles and CoMo-LDH, which accelerate the electron and mass transfer, provide a large number of new active sites and optimize the activity of the original sites. Impressively, Ag@CoMo-LDH also exhibited promising practical prospect on account of the remarkable cyclic and long-term stability. This finding demonstrates that pointedly integrating multiple strategies into one system is a promising way to construct new LDH-based OER electrocatalysts with synthetically improved performance, providing a promising model for developing advanced electrocatalysts in energy conversion devices.

Evaluation of the Support Structure Removal Techniques for Additively Manufactured Ti6AL4V Parts

Support structures are required for overhanging surfaces in additive manufacturing to prevent part deformation. However, these support structures are undesirable because they are removed during postprocessing after the part is built. It is critical to remove metal support structures because they can occasionally leave residue on the part. Among the various support-removal techniques, manual removal and wire electrical discharge machining (EDM) are the most frequently used. While most manufacturers recommend the manual method due to its economic benefits, it may be challenging for thin walls, small-scale components, and brittle materials. The purpose of this study is to evaluate and compare these two methods, taking into account both their advantages and disadvantages. The results indicate that while manual support-removal is quick, it results in a degraded surface topography and increased surface roughness due to support tooth remnants and residue. The wire EDM method of removing support resulted in a more uniform surface topography and a superior surface finish. However, as a result of thermal damage, a heat-affected zone developed on the machined surface.

Determination of yearly performance and degradation rate of electrical parameters of amorphous silicon photovoltaic module in Minna, Nigeria

There is need for accurate knowledge of degradation rate and lifespan of photovoltaic (PV) module in every location for an effective solar PV power system. Outdoor degradation analysis was carried out on amorphous silicon PV module rated 10 W using CR1000 software-based Data Acquisition System (DAS). The PV module under test and meteorological Sensors were installed on a metal support structure at the same test plane. The data monitoring was from 09:00 to 18:00 hours each day continuously for a period of four years, from December 2014 to November 2018. Annual yearly averages of the performance variables were carried out to ascertain the degradation rate and lifespan of the module. The module performance for the four years of study was compared with Standard Test Condition (STC) specifications. The maximum power achieved at 1000W/m2 for the four years of study were 0.652W, 2.186W, 2.078W, and 1.812W representing 6.52%, 21.86%, 20.78% and 18.12%of the manufacturer’s 10W specification. Module efficiency at 1000W/m2 for the four years of study is 2.25%, 7.56%, 7.19%, and 6.27% respectively as against the manufacturers STC specification of 33%. Accordingly, Module Performance Ratios for the PV module investigated were 0.07, 0.23, 0.22 and 0.19 respectively. For the Rate of Degradation (RoD), it was observed that Open-Circuit voltage (Voc), Short-Circuit Current (Isc), Power-Output (P), Maximum Power (Pmax), had an average yearly degradation rate of 0.73V, 0.010A, 0.040W, 0.050W respectively for the four years of study. To also determine the lifespan of the module, an empirically determined statistical model given as YEAR = 3.36 - 0.237 Voc (v) - 71.5 Isc (A) + 8.07 Power (W) was fitted to the observed data to predict the lifetime of the module at any given year.Â

Optimization of the constructive system lining of metallic support structures in order to reduce deformation speeds of horizontal mining works executed in deep layer sedimentary rocks

Mining works executed in deep layer sedimentary rocks, are exposed to large deformation speeds during exploitation, because of rock pressure applied on the walls, the ceiling and bedrock of excavations. In this paper, we aim to find a solution for optimizing the constructive metallic structures, and subsequent linings, through the improvement of the transmission way of loads originating in rock pressure. According to Panet – Sulem support/rock interaction, there is a possibility of guiding rock pressure through constructive support system.

Metallic support and fastening structures for photovoltaic modules - case study: implementation in a company in the industrial district of Manaus / Estruturas metálicas de suporte e fixação para módulos fotovoltaicos – estudo de caso: implantação em uma empresa no distrito industrial de Manaus

Given the exponential growth of studies in the area of energy efficiency, energy quality, and the intense search for modernity and energy production that has been causing a series of changes in our behavior and, especially, in the environment. Along with this, we have seen a great development of the so-called renewable technologies in our daily lives, such as the insertion of photovoltaic panels and wind power plants, for example. However, they tend to be impacted by several factors, such as dirt, temperature, degradation, orientation angle and inclination, as well as terrain topography and module manufacturing quality. The present work aims to contribute to a better understanding of the use of metallic support and attachment structures for photovoltaic modules by proposing effective methods for their installation. Based on this context an analysis of the viability of the site, the usable area for the installation of the modules, the definition of the components, the cost estimate for the execution of the project, the sustainability of the photovoltaic system, as well as the analysis of quality and maintenance were performed. The results show that a quality execution requires a whole planning that must be followed correctly step by step, as well as its characteristics and alternative solutions, thus enabling its insertion in the urban environment.

Determination of Yearly Performance and Degradation Rate of Electrical Parameters of a Monocrystalline Photovoltaic Modules in Minna, Central Nigeria

Outdoor degradation analysis was carried out on a monocrystalline PV module rated 10 W using the CR1000 software-based Data Acquisition System (DAS). The PV module under test and meteorological Sensors were installed on a metal support structure on the same test plane. The data obtained was monitored from 09:00 to 18:00 hours each day continuously for a period of four years, from December 2014 to November 2018.The experiment was carried out near the Physics Department, Federal University of Technology, Minna (latitude 09o37'N, longitude 06o32'E, and 249 meters above sea level). The sensors were connected directly to the CR1000 Campbell Scientific data logger, while the module is connected to the logger via electronic loads. The logger was programmed to scan the load current from 0 to 1 A at intervals of 50mA every 5 minutes, and average values of short-circuit current, (Isc,) open-circuit voltage, (Voc), current at maximum power, (Imax), the voltage at maximum power,(Vmax), power and maximum power obtained from the modules together with the ambient parameters are recorded and logged. Data download at the data acquisition site was performed every 7 days to ensure effective and close monitoring of the data acquisition system (DAS). At the end of each month and where necessary, hourly, daily and monthly averages of each of the parameters-solar irradiance, solar insolation, wind speed, ambient and module temperatures, and the output response variables (open-circuit voltage, Voc, short-circuit current, Isc, the voltage at maximum power, Vmax, current at maximum power, Imax, efficiency, Eff, and fill factor, FF) of the photovoltaic modules were obtained.Yearly averages of the performance variables were obtained to ascertain the performance, degradation rate, and lifespan of the module. The module performance for the four years of study was compared with Standard Test Condition (STC) specifications. The maximum power achieved at 1000W/m2 for the four years of study are 0.711W, 1.82W, 0.50W, and 0.22W representing 7.11%, 18.39%, 5.0% and 2.25% of the manufacturer’s 10W specification. Module efficiency at 1000W/m2 for the four years of study is 3.30%, 10.12%, 3.98%, and 2.82% respectively as against the manufacturer's STC specification of 46%. Accordingly, Module Performance Ratios for the PV module investigated were 0.072, 0.22, 0.087, and 0.061respectively. For the Rate of Degradation (RoD), it was observed that Open-Circuit voltage (Voc), Short-Circuit Current (Isc), Power-Output (P), and Maximum Power (Pmax), has an average yearly degradation rate of 1.06V, 0.002A, 0.082W and 0.142W representing 4.9%,0.30%,0.56%, and 1.4%respectively for the four years of study.

Stray-Capacitance As a Simple Tool for Monitoring and Locating Heat Generation Demonstrated in Three Superconducting Magnets

Real-time monitoring of heat loads in cryogenic systems is critical for many applications, particularly high field magnets. We demonstrated that by monitoring changes in the capacitance of local probes consisting of thin metal strips with a porous glass fiber dielectric, boiling helium from as little as 0.1 J of deposited heat can be located by an analysis of the response speed and amplitude in nearby probes. We further implemented stray-capacitance monitoring of a magnet's metal support structures, a more global probe of the magnet volumes, in three high temperature superconducting Bi-2212 magnet types. Global structural stray-capacitance monitoring was evaluated for a single racetrack coil, a common coil dipole, and a canted cosine theta winding, showing a quench response comparable to voltage signals without inductive effects. The response of the local and global probes was compared in the single racetrack coil with well-known quench properties. Monitoring the cool-down of the common coil dipole demonstrated the added benefit of the global stray-capacitance as a liquid level monitor. This simple method of monitoring the capacitance has proven to be a versatile and robust technique for monitoring and locating heat.

Wire EDM Parameter Optimization of AlSi10Mg Alloy

This work attempts to optimize the multi-objective characteristics of wire electrical discharge machining (WEDM) in SLM-fabricated AlSi10Mg through a hybrid artificial neural network (ANN) coupled genetic algorithm approach. The SLM is unambiguously one of the most effective commercially viable successful additive manufacturing (AM) technologies that have the potential to replace many traditional methods of manufacturing. However, the highly intricate metallic support structures created in SLM are too strong to be eliminated by hands for which precision machining operations such as WEDM are widely employed for post-processing of SLM–AlSi10Mg. The Taguchi experimental design, considering the three most influencing factors, is performed to obtain micro-hardness and surface roughness results. The input factors for optimization are discharge current, discharge voltage, and pulse time-on in the WEDM process. The multi-objective optimization is performed using the ANN coupled GA approach where the ANN model has been generated first and the results of the best model are fed to GA for optimization. For this, five variants of three-layered, multi-perceptron models with feed-forward (BP) neural structures are also developed. The current model is supplemented with a Levenberg–Marquardt algorithm that uses logarithmic sigmoid (logsig) and linear (purelin) transfer functions. Finally, the response values from the best ANN model (3–10–2) are employed for multi-objective optimization using GA. The present study establishes the following optimized process parameters: 12 A discharge current, 42 V discharge voltage, and 12 µs time-on for maximized micro-hardness of 478 VHN and minimized surface roughness of 4.3 µm, both with greater than 98% confidence level. The present study reports briefly phase characterization such as the presence of Si particles, α-Al, and Mg2Si phases on the recast surface. The surface quality of the optimized specimen exhibits superior surface quality than its other experimental counterparts.

Analysis of the dynamic forces acting on a vibrating screen and its support structure using a scale model

Vibrating screens are equipment used in various industries, such as mining, steel and food. Although it is simple to install vibratory equipment on a support structure, it is necessary to consider the static and dynamic forces caused by vibration. The present work aims to perform a dynamic analysis of a vibrating screen and measure the dynamic forces transmitted to its metallic support structure, by means of the acceleration g collected. For this, a model of a prototype vibrating screen was created to perform vibration tests, the data were collected on the equipment using accelerometers positioned at strategic points through magnetic devices. In this way, the values obtained by the instrumentation were compared with the theoretical data obtained through a proposed analytical calculation. Analysing the vibrating screen, graphs were made to compare the displacements, resulting in minimal differences between the experimental and analytical data. Specially for this model, the results show that between 1100 rpm and 1400 rpm is the best frequency to obtain results in terms of efficiency and sieving, with less impact on the equipment and its structure. Analysing the forces transmitted from the vibrating screen to its structure, the analytical and experimental values were quite different, mainly at higher frequencies.

Effect of metal dispersion and support structure of Ni/silicalite-1 catalysts on non-thermal plasma (NTP) activated CO2 hydrogenation

Non-thermal plasma (NTP) activated heterogeneous catalysis is a promising alternative to thermal catalysis for enabling many challenging reactions (e.g. catalytic CO2 hydrogenation) under mild conditions. However, the mechanistic insight into the interaction between highly energetic electrons and vibrationally-exited reactive species with metal catalyst is still lacking. Here, catalytically active Ni nanoparticles supported on silicalite-1 zeolites with different configurations regarding the location of Ni active sites and support pore structures were comparably investigated using catalytic CO2 hydrogenation under the thermal and NTP conditions. Experimental results revealed that the performance of the NTP-catalysis depends on the configuration of the catalysts significantly. Specifically, catalysts with Ni active sites sit on the outer surface of zeolite crystals (i.e. microporous Ni/S1 and Ni/M-S1@Shell with steam-assisted recrystallised micro-meso-porous structure) showed relatively good catalytic performance at a low applied voltage of 6.0 kV. Conversely, the encapsulated catalyst with hierarchical meso-micro-porous structure (i.e. Ni/D-S1) which has relatively small (i.e. average Ni particle sizes of 2.8±0.7 nm) and dispersed Ni nanoparticles (i.e. Ni dispersion of ca. 2.5 %) demonstrated comparatively the best catalytic performance (i.e. CO2 conversion of ca. 75 %) at 7.5 kV. Additionally, under the NTP conditions studied, Ni on carbon-templated mesoporous silicalite-1 (Ni/M-S1) showed the worst selectivity to CH4, which was attributed to the poor accessibility of Ni active sites encapsulated in the enclosed mesopores. This study demonstrated the crucial role of catalyst design in NTP activated catalysis.

Removability of 316L stainless steel cone and block support structures fabricated by Selective Laser Melting (SLM)

Support structures are needed due to the complexities of induced structural, thermal and process factors in Selective Laser Melting (SLM). To date, little systematic study is found to unveil the support removability by a post-machining process. This paper presents an experimental study of removing 316L stainless steel cone and block supports by milling. The effect of different supports is identified by the variation in the microhardness distribution and microstructure of the workpieces. The milling performance of cone and block supports at different cutting depths is studied on the surface finish, surface roughness, milling force, and tool wear and chip formation. The cone supports are subjected to severe collapse, whilst the block supports are mainly removed by localized shearing. The milling force and specific cutting energy of cutting block supports are lower than that of cone supports, and so is the tool wear. A finite element method (FEM) model is developed to explain the removal mechanisms. The results of this study provide an essential reference and unique insight into removal of metal support structures. Moreover, the removability of supports, which is derived from the post-processing stage, should be considered as a new factor in the support design for additive manufacturing.

Iridium Atoms Bonded to Crystalline Powder MgO: Characterization by Imaging and Spectroscopy

Samples with low loadings of metals on well-defined supports provide some of the best opportunities to determine the metal–support structure and bonding. We illustrate methods for characterizing at...

CFD modeling of the OSU High Temperature Test Facility inlet plenum flow distribution during normal operation

This paper investigates the fundamental physical phenomena associated with internal coolant flow distribution in the upper plenum of a prismatic Very High Temperature Reactor (VHTR) during normal operation. Previous studies have revealed the importance of complex flow distribution in the inlet plenum with the potential to generate low velocity or stagnation zones that can subsequently lead to the formation of hot spots in the reactor core and hot streaks in the lower plenum. It is therefore of interest to ensure that coolant is evenly distributed when entering multiple reactor coolant channels. Non-uniformity in the flow distribution is assessed for the reference Oregon State University High Temperature Test Facility (HTTF) case. The HTTF is a reduced scale model (1:4 in height and diameter) of the Modular High Temperature Gas-Cooled Reactor (MHTGR). The developed CFD model reflects complete and detailed geometry of the HTTF upper plenum along with upcomer and metallic core support structure (MCSS). CFD results include parametric studies performed for circulator mass flow rate variation and mesh sensitivity analysis, generated using Siemens Starccm+ software. Outcomes also include variable pressure and temperature boundary conditions impact on the flow distribution.