Non-uniform Diameter Research Articles

Numerical Investigation of Process Parameter Effects on Flow Oscillations in a Natural Circulation Boiling Integral PWR-Type SMR Test Rig

Innovative reactor designs like small modular reactors (SMRs) have the potential to operate in a natural circulation (NC) boiling mode, but this mode introduces flow oscillations that pose a risk to nuclear safety. Therefore, it is essential to investigate the effects of various parameters on these oscillations. This study focuses on predicting the operational behavior of the Integral PWR-type SMR Test Rig (iPSTR) when operating in NC and subcooled boiling conditions. The iPSTR replicates an NC boiling loop with a vertical heater, vertical cooler configuration, high-temperature and high-pressure conditions, and nonuniform diameter structure. Using the RELAP5 model, thermal-hydraulic simulations were performed to anticipate how varying degrees of inlet subcooling affects parameters such as mass flow rate and void fraction, with experimental data used to validate the model’s accuracy. This investigation covers a range of process conditions, including system pressures from 5 to 20 bars, core input power varying from 8.5 to 14.5 kW, and degrees of inlet subcooling from 1 to 49 K. The results reveal that increasing input power leads to higher average mass flow rates, while at a constant system pressure, higher input power stabilizes flow rates at higher degrees of inlet subcooling. Moreover, reduced and more consistent oscillation amplitudes and frequencies at higher core power result at more elevated system pressure, enhancing the safety of the iPSTR facility.

LES of autoignition process in a turbulent droplet-laden mixing layer – impact of an evaporation model and discretisation method

This paper focuses on the numerical modelling of the autoignition process in an ethanol-air mixture within a turbulent droplet-laden temporally evolving mixing layer, utilising the Large Eddy Simulation (LES) method. We compare results obtained by implementing two notably distinct discretisation methods (second-order Total Variation Diminishing – TVD, and fifth-order Weighted Essentially Non-Oscillatory – WENO) in the species and energy transport equations. Additionally, we examine three widely recognised evaporation models (the ‘ D 2 ’ model, the Abramzon–Sirignano model, and a non-equilibrium model based on the Langmuir-Knudsen law). For modelling the combustion process, we employ the Eulerian Stochastic Field method and a laminar chemistry model. The simulations encompass two droplet diameter distributions, one with low and the other with significant diameter non-uniformity. Furthermore, nine distinct initial conditions are considered. Our findings indicate that adjusting the discretisation scheme or the evaporation model can yield simulation outcomes differing to a substantial degree, similar to the impact of modifying the actual properties of the spray droplets or their initial distribution. This is particularly pronounced in the case of sprays featuring a narrowed droplet diameter distribution. We found that the Abramzon–Sirignano model results in the most rapid autoignition. The TVD scheme contributes to a more even spatial distribution of the evaporated fuel, consequently facilitating quicker evaporation and faster autoignition. Using the WENO scheme generates higher fuel vapor gradients near the droplets, leading to less intense evaporation and slower fuel transport in space.

Fabrication of electrostatic-induction-assisted solution blowing spinning nanofibers and its mechanism

Commonly used nanofiber fabrication technologies have many shortcomings: the yield of electrospinning is low, solution blowing spinning (SBS) and its improved technologies have problems with large fiber diameter, non-uniform nanofiber diameter and poor receiving aggregation of nanofibers on receiver. A nanofiber fabrication technology called electrostatic-induction-assisted solution blowing spinning (ESBS), which overcomes these disadvantages, was developed in this paper. This technology utilizes the joint action of electrostatic force and airflow stretching force to stretch the jet to fabricate nanofibers. The grounding of the blunt needle realizes the directional migration and dynamic circulation of charges in the ESBS microscopic system. Compared with traditional SBS, the average diameter and diameter standard deviation of ESBS nanofibers can be reduced by 44 % and 80.8 %, respectively, and the fiber cover rate can be increased by 329.7 %. In contrast to the cylindrical-electrode-assisted solution blowing spinning, the mean diameter and diameter standard deviation of ESBS nanofibers can be reduced by 34.6 % and 68.1 %, respectively, and the fiber cover rate can be increased by 305 %. The microcosmic fabrication mechanism of ESBS nanofibers—“the theory of separation and directional transfer of charges” was proposed and verified. ESBS nanofibers with single-needle injection speed up to 200 μl/min (far exceeding the 4–10 μl/min injection speed of conventional electrospinning) were successfully fabricated to prove that this technology has great industrial potential. ESBS nanofibers with small and uniform diameter, high yield, and good receiving aggregation of fibers on receiver have bright application prospects in many fields.

The investigation of V-shaped arrays with non-uniform diameter cylinders for high performance hydrokinetic energy conversion

Harnessing hydrokinetic energy through vortex-induced vibration (VIV) is of great significance. The energy capture efficiency of VIV cylindrical arrays still has great potentials for making further progress. This paper investigates the energy conversion performance of cylinder cluster arrays with non-uniform diameter positioned at the upstream, midstream, and downstream locations, utilizing the downstream VIV enhancement effect. The cylinder arrays consist of five cylinders with non-uniform diameters of 2, 3, and 4 cm, resulting in a total of eight different V-shaped configuration scenarios. Through numerical simulation, it is found that the optimal flow velocity for maximizing the cylinder vibration amplitude is 0.8 m/s. In the condition of 0.8 m/s flow velocity, this study investigates the impact of cylinder diameter and the array arrangement on lift force, amplitude response, vortex shedding frequency, converted power, and efficiency. If the diameter of a cylinder is smaller than that of its upstream cylinder, cylinder experiences an enhanced amplitude, and the magnitude of this enhancement increases with the difference in diameters between the two cylinders. The blocking effect in the cylinder array occurs at a distance of two times the diameter. It has been observed that the small diameter cylinder demonstrates exceptional performance, achieving the highest converted power of 6.58 W (88% higher than the single cylinder) and the highest conversion efficiency of 68 % (75% higher than the single cylinder) in the convergent V-shaped array. The divergent V-shaped array achieves a maximum total converted power of 17.12 W (14% higher than the average conversion efficiency of single 2 cm, 3 cm, 4 cm cylinders), while the convergent V-shaped array achieves a maximum total conversion efficiency of 44% (24% higher than the average conversion efficiency of single 2 cm, 3 cm, 4 cm cylinders). This study presents an innovative perspective on the VIV enhancement effect in energy conversion, specifically focusing on multi-cylinder arrays with non-uniform diameters.

Performance evaluation of a novel monofilar helical antenna with tapered cross-section wire fabricated via metal additive manufacturing

This paper presents a novel formulation for a generalized helical antenna that incorporates non-uniform helix diameters, non-uniform helix spacing, and non-uniform wire cross-section, providing additional degrees of freedom for optimization. By carefully defining the transition between the helix and the center feed point, a thicker wire was used at the base to enhance the antenna’s operating bandwidth capability and mechanical strength, eliminating the need for additional support structures. The fabrication process utilized metal additive manufacturing (MAM) with Maraging steel. The results demonstrate that the helical antenna with a tapered cross-section wire (with a thicker base and a thinner tip) exhibits significantly better performance compared to the control models for operation in the X-band. This design amalgamates impedance matching from antennas with uniform thick wires and radiation characteristics from antennas with uniform thin wires. The major contribution of this work is the demonstration that employing tapered wire cross-sections can enhance helical antenna performance, thereby introducing a new design parameter in metal additive manufacturing. Specifically, we present an eight-turn helical antenna that achieved a measured reflection coefficient less than −10 dB and axial ratio less than 1 dB over the X band, with a peak realized gain in RHCP of 10.8 dBic.

Моделирование эрозионного износа титанового сплава высокоскоростным потоком частиц

Introduction. Predicting solid particle erosion (SPE) in gaseous flow and managing its intensity is still a relevant problem in mechanical engineering. It requires the development of a general modeling methodology, which also depends upon many special cases studying various physical processes. Such studies should also include verification analysis, process parameters and model sensitivity studies. Mainly computational fluid dynamics and finite element analysis (and mesh-free methods such as smooth particle hydrodynamics or similar) are used to simulate the erosion process. Papers focused on CFD simulation of solid particle erosion of metal alloys are widely presented, but most of it is associated with relatively low or medium particle velocities (< 100–150 m/s) and is close to uniform diameter distribution. This paper presents a CFD study of Ti6Al4V titanium alloy SPE at relatively high particle velocities and sufficiently non-uniform unimodal particle diameter distribution. The paper also studies the turbulence model influence and particle shape effect which appears as a “shape factor” coefficient in the particle drag model. Methods. The heterogenous flow simulation was based on the Reynolds-averaged Navier-Stokes formulation, where the particles, according to Euler-Lagrange formulation, were simulated as mathematical points with corresponding properties. The influence of turbulence models, such as k-epsilon standard, RNG k-epsilon, and a relatively new Generalized equation k-omega (GEKO) model and its coefficients were also studied. Oka and DNV erosion models were also compared based on the general sample mass loss and more specific erosion intensity profile criterions. The simulation results were compared to the lab-scale experimental results. Results and discussion. It is shown that neither erosion intensity profile or sample mass loss do not depend upon the turbulence model choice or GEKO parameters variation. As expected, erosion is dependent on the erosion model and its coefficients. A notable influence of the shape factor is shown. As the drag coefficient increased due to the particle shape, the erosion intensity decreased and the erosive profile on the surface also changed due to the changing velocity and diameter distribution of the heterogenous flow. It is expected that such results would be useful not only for erosion prediction in all areas of mechanical engineering, but also for wear management in mechanical assemblies and shot peening / shot peen forming management and simulation.

Thermochemical isolation and characterization of nanofibrillated cellulose from Stipa obtusa fibers

This research aimed to establish a methodology for isolating and characterizing nanofibrillated cellulose (CNF) from Stipa obtusa, using low concentrations of reagents and their characterization. The fibers were collected in high Andean areas of Cusco in Peru, treated with the alkaline-assisted steam explosion, followed by bleaching and acid fibrillation procedures, and with steam explosion, using solutions with varying concentrations of oxalic acid. The CNF was characterized by analytical methods according to TAPPI standards and using XRD, FTIR, SEM, TEM, and TGA techniques. The optimum values for obtaining the CNFs were: alkaline treatment with NaOH 0.5 M and acid treatment with 8% (m/m) of oxalic acid. These parameters were used to obtain a CNF network with a non-uniform surface and diameters between 19 and 27 nm, 82.97% (m/m) of cellulose, and a crystallinity index of 52.92%. Furthermore, the results showed a progressive partial elimination of lignin and hemicellulose at each stage of isolation.

The Influence of Wire Diameter Uniformity on the Quality of Fiber Optic Wire Package

The fiber optic wire package is the core component of fiber optic guided rockets. Due to the non-uniformity of the fiber optic wire diameter, the winding process is prone to winding defects, which affects the missile launch process. In this paper, a finite element simulation model for the winding process of the fiber optic wire package is established. The accuracy of the simulation model is verified by comparing it with the analytical model for the contact pressure between fiber optic layers. Then finite element models considering the wire diameter tolerance are established to analyze the effect of diameter uniformity on the winding quality of the fiber package. The results show that the stress distribution of a fiber optic package becomes increasingly uneven with increasing wire diameter non-uniformity, and the structural stability of the package decreases. The edge fibers of a 20-layer optical fiber package are easily extruded when the deviation from the nominal diameter is more than 3%. This study helps to guide the manufacturing accuracy of optical fibers and improve the structural stability of the wire package.

A novel triple-diameter pulsating heat pipe: Flow regimes and heat transfer performance

A single-turn triple-diameter pulsating heat pipe (TD-PHP) with a total length of 250 mm (the evaporation, adiabatic, and condensation lengths were 25 mm, 125 mm, and 100 mm, respectively) made of a transparent Pyrex glass was designed and fabricated for the first time. The thermal performance and flow characteristics of the TD-PHP were compared with two other fabricated PHPs, the single-diameter (SD) and dual-diameter (DD) PHPs, to determine the effect of non-uniform channel diameters. The PHPs were mounted on a tilting frame, and their thermal performances were tested with various heat inputs, inclination angles, and filling ratios. The temperatures of the evaporation, condensation, and adiabatic sections and flow behaviors were monitored. Results indicated that circulating flow was enhanced by using TD-PHP, and thermal resistance was reduced considerably. The visualization results showed that the bubbles' generation, growth, and breakage leading to enlarged vapor plugs were enhanced because of the unbalanced gravitational forces owning to the channel with non-uniform diameter. Hence, the TD-PHP was functional even at inclination angles near the horizontal angle.

Inverse design of GaAs nanowire array solar cell structures with nonuniform diameters

Non-uniform diameter GaAs nanowire array solar cell structures are designed using the particle swarm optimized inverse design method. The results show that unlike the uniform diameter structure, which has a series of absorption valleys, the absorption spectra of the non-uniform structures are much flatter, which is attributed to a combination of absorption spectra from nanowires of different diameters. For the same height, the optimized structure with non-uniform diameter yields a remarkable ultimate efficiency of 34.3%, 1.1% higher than that the structure with uniform diameter, mainly due to the enhanced absorption at long wavelengths. For the same volume, an even higher ultimate efficiency of 34.6% is obtained, due to the enhanced absorption over almost the entire wavelength range. This work could pave the way for the design of low-cost high-efficiency nanoscale solar cells and other photoelectric conversion devices.

Indications of a more complex DNA toroid formation.

The compaction of DNA in sperm is at semi-crystalline levels, reaching nearly the physical condensation limit. This incredible compaction is carried out by a positively charged condensing agent, the protein protamine. Many protamines bind to the negatively charged DNA backbone, each creating a bend that eventually forms a loop. Our goal is to determine how protamine compacts the DNA even further to form toroids. Using atomic force microscopy (AFM), we imaged samples of varying lengths of DNA (1-48 kbp) under varying concentrations of protamine (0.1-3 μM). This allowed us to isolate folding states in the toroid formation pathway. It is thought that toroids are formed loop by loop and create a hexagonally packed toroid. However, we observed structures with many unstacked loops that look like flowers, vertical stacks of several loops, rod-like structures with approximately the thickness of a toroid, and toroids with nonuniform diameter and height. These structures suggest that the DNA toroid formation pathway could be more complex than we first thought. Could there be multiple pathways for the formation of toroids? Here we will present our progress toward determining toroid formation mechanisms. Understanding the physics of DNA compaction into a toroid may have interesting nanoengineering applications.

Revisiting the effect of sabot on the incident signals of split-Hopkinson pressure bar

In typical split-Hopkinson pressure bar set-ups, the striker bar is propelled in a barrel of larger diameter. Teflon/brass sabots are used to concentrically-align the striker inside the barrel. The influence of the area mismatch between barrel and striker, length of the sabots and interface condition between sabot and striker are analyzed in detail using finite element simulations. We show that for a given geometry of the sabot, a frictionless interface does not alter the incident signals. In the presence of friction, the incident signals deviate from the classical trapezoidal shape. The magnitude of the deviation depends on the geometry of the sabot. As an alternative to the shrink/press fitted sabot, a stepped striker is used to eliminate some issues faced during the usage of the shrink/press-fitted sabot. The stepped striker has a non-uniform diameter such that at two locations its diameter is that of the barrel, and at other locations it has the same diameter as the incident bar. The influence of the geometry of the stepped striker on the distortion of the incident signal is investigated in detail using the method of characteristics. A parametric study is used to quantify this distortion for various geometric configurations of the stepped striker. Three striker geometries are chosen from these configurations to validate the parametric study using experiments. High strain rate characterization of SS304 is also carried using these strikers to illustrate the effect of the geometry of the stepped striker on the stress versus strain and strain rate versus strain response.

Enhancing mechanical properties of flash-spun filaments by pressure-induced phase separation control in supercritical high-density polyethylene solution

Flash-spun nonwoven (FS-NW) is gaining attention in the PPE field due to its excellent barrier and mechanical properties resulting from its non-uniform diameter distribution and unique filament morphology. The unique network structure of flash-spun filaments (FSF) comprising the FS-NW can be controlled by phase separation behavior in the supercritical fluid (SCF) process. This study proposes a simple method to control the microstructure of FSFs by controlling the pressure-induced phase separation (PIPS) process in polymer/SCF solution. This phase separation behavior of an HDPE/SCF solution was confirmed by using a high-pressure view cell. A multistage nozzle allowing for phase-separated pressure to form different phases was also designed. HDPE-FSFs were synthesized by flash-spinning, and their morphology, crystallinity, and mechanical properties were investigated. The results demonstrated that the filaments obtained by PSP control at 220 °C and with an HDPE concentration of 8 wt% showed a network structure composed of strands, wherein the diameters ranged from 1.39 to 40.9 μm. Optimal FSF was obtained at 76 bar, with a crystallinity of 64.0% and a tenacity of 2.88 g/d. The PIPS method can thus effectively control the microstructure more feasibly than temperature- or solvent-induced techniques and can allow the effective synthesis of various products.

Coulombic force contribution to nano scale aerosol capture by a wire grid: Quantitative comparison of experiments and simulations

Fibers of filter media and aerosol particles both typically have some distributions of electric charge. Attractive coulombic interactions between charged particles and fibers enhance aerosol filtration efficiency; however, these coulombic interactions are difficult to characterize due to the complex, nonuniform fiber charge, diameter and spacing of typical filter media. We develop an experimental filter assembly to control these coulombic interactions. The filter assembly consists of three sequential electrically isolated metallic grids—high voltage is applied to the middle grid and the adjacent outer grids are electrically grounded such that the electric potential distribution in the filter assembly is well-defined. We test this filter assembly with aerosols of controlled diameter (ranging between ∼70 and 500 nm) and electric charge (1e−), and systematically increase the applied voltage to the middle grid to enhance coulombic interactions and consequently the filter efficiency. We develop particle trajectory simulations to model our experimental filter assembly such that all parameters in the simulation have direct basis from the experimental system. We find excellent quantitative agreement between the filter efficiency measured in experiments and predicted from simulations without any fitting parameters. The precise control and accurate simulation of coulombic interactions demonstrated in this study indicate that the experimental and simulation methodologies developed here may be applied to uncover fundamental insights into the role of coulombic forces in more complex phenomena such as filter clogging.

Developing a novel technique for the fabrication of PLA-graphite composite filaments using FDM 3D printing process

Developing a uniform polymer-based composite filament is a critical factor for a successful 3D printing process. In this regard, a novel technique for the fabrication of PLA-graphite filament with the potential to be applied to other PLA-based composite filaments was proposed and compared to the solvent casting method. This modified mixing technique involves partial dissolution of the PLA pellets surface by dichloromethane (DCM), which creates a sticky surface for the strong adhesion of reinforcement powders. The manufactured composite filament by this method exhibited excellent structural features, while the solvent casting method yielded a heterogeneous filament with a non-uniform diameter and numerous voids. In addition, graphite, as a cost-effective carbon-based filler for polymer matrix composites, could effectively act as a reinforcement phase, leading to noticeable mechanical strength enhancement of PLA. Furthermore, significantly enhanced printability and mechanical properties of 3D-printed PLA-graphite composite specimens indicate the efficiency of the modified mixing method as a practical and time-saving technique for developing uniform PLA-based composite filaments for the extrusion-based additive manufacturing techniques such as FDM.

Retracted: Water Transport in GDL Microstructures of Nonuniform Fiber Diameter Arrangement

In proton exchange membrane fuel cells (PEMFCs), the gas diffusion layer (GDL) plays an important role in the transport of reactants, water, heat, and electrons. Microstructure manipulation of porous media via a nonuniform fiber diameter arrangement could potentially be used to improve water transport behavior in GDLs. A numerical modeling approach is used to simulate GDL microstructures with uniform and nonuniform fiber diameters. The reconstructed porous microstructures’ water saturation and porosity are compared. The simulations of three-dimensional (3D) two-phase flow volume of fluid (VOF) models were completed on the OpenFOAM platform using the finite volume method (FVM). Simulations demonstrate that by adopting a nonuniform microstructural fiber diameter design, both porosity and water transport behaviors can be altered. As a result of the nonuniform fibrous arrangement, the ability to improve GDL performance by controlling water transport and porosity is possible. The results indicate that by manipulating the GDL microstructure, additional water pathways can be created, resulting in slightly increased water saturation. We propose that water transport can be improved by microstructural manipulation of the GDL, specifically by optimizing the arrangement and position of nonuniform fibers.

Impact of Non-Uniform Periodic Magnetic Field on Unsteady Natural Convection Flow of Nanofluids in Square Enclosure

In this article, unsteady free convective heat transport of copper-water nanofluid within a square-shaped enclosure with the dominance of non-uniform horizontal periodic magnetic effect is investigated numerically. Various nanofluids are also used to investigate temperature performance. The Brownian movement of nano-sized particles is included in the present model. A sinusoidal function of the y coordinate is considered for the magnetic effect, which works as a non-uniform magnetic field. The left sidewall is warmed at a higher heat, whereas the right sidewall is cooled at a lower heat. The upper and bottom walls are insulated. For solving the governing non-linear partial differential equation, Galerkin weighted residual finite element method is devoted. Comparisons are made with previously published articles, and we found there to be excellent compliance. The influence of various physical parameters, namely, the volume fraction of nanoparticles, period of the non-uniform magnetic field, Rayleigh number, the shape and diameter of nanoparticles, and Hartmann number on the temperature transport and fluid flow are researched. The local and average Nusselt number is also calculated to investigate the impact of different parameters on the flow field. The results show the best performance of heat transport for the Fe3O4-water nanofluid than for other types of nanofluids. The heat transport rate increases 20.14% for Fe3O4-water nanofluid and 8.94% for TiO2-water nanofluid with 1% nanoparticles volume. The heat transportation rate enhances with additional nanoparticles into the base fluid whereas it decreases with the increase of Hartmann number and diameter of particles. A comparison study of uniform and non-uniform magnetic effects is performed, and a higher heat transfer rate is observed for a non-uniform magnetic effect compared to a uniform magnetic effect. Moreover, periods of magnetic effect and a nanoparticle’s Brownian movement significantly impacts the temperature transport and fluid flow. The solution reaches unsteady state to steady state within a very short time.

Thermal/fluid characteristics of the inline stacked plain‐weave screen as solar‐powered Stirling engine heat regenerators

The present work demonstrates the results of a 3D numerical analysis of heat transfer and fluid flow through a fabricated aluminium wire filament, bonded mesh deployed as a regenerator surface in the Stirling engine. Here, two inline regenerator models with the same mass but different geometry were simulated by computational fluid dynamics (CFD) and finite element method (FEM). The results show that the temperature efficiency of both inline with non-uniform and uniform wire diameters is almost equal. However, the non-uniform diameter model is shorter and reaches the maximum thermal efficiency faster in reduced length < 18 $ < 18$ . Also, it shows approximately 5% a greater mean thermal efficiency. In general, from this simulation, it can be seen that changes in the geometry of the heat regenerator can have a direct effect on thermal efficiency and pressure drop in the same mass. Therefore, using the inline stacked plain-weave screen with a non-uniform wire diameter regenerator in the powered Stirling engine is recommended due to space constraints. Small changes in the regenerator geometry lead to immense leaps in increasing a solar power plant's overall efficiency.

Analysis of compression in uniform and non-uniform GDL microstructures on water transport

ABSTRACT A 3D compressed gas diffusion layer (GDL) microstructure is developed based on the finite volume method (FVM) and used to evaluate water transport behavior. The compressed GDL microstructure and two-phase flow VOF model are developed and validated on the OpenFOAM CFD platform. The models are compared to experimental data, with good agreement. Consequently, the reconstructed GDL microstructures are subjected to compressive stresses. The water uptake behavior in the compressed samples with different (CR) compression ratios (10% CR, 20% CR, and 40% CR) is compared to that in an uncompressed GDL microstructure. Also, the effects of GDL wettability, water pressure, and non-uniform fiber diameter arrangement in GDLs are investigated. In GDL microstructures, two-phase interaction is influenced by the GDL contact angle, compression ratio, water inlet pressure and capillary pressure. It is found that excessive compression on GDLs constricts the pores, thereby restricting access of water through the pores. As such, 10% CR was found to be the safe limit with just 8% saturation drop. On the other hand, altering the fiber structural arrangement through unequal-sized fiber diameter had very little impact on water saturation in the through-plane direction of both the uncompressed and compressed GDL microstructures. As such, the excessive introduction of the unequal-sized fibers may not be the right choice, especially under compressive forces. Thus care must be taken in the treatment of GDL carbon papers and clamping force during assembly since these significantly influences water patterns in them.

Non-kinetic phenomena in thermal analysis data; Computational fluid dynamics reactor studies

Computational fluid dynamics (CFD) has been used to develop a characterisation method for the transport phenomena occurring within thermal analysis reactors. This method allows the comparison of different equipment configurations to identify which are most suitable for obtaining intrinsic data. In this work, four equipment configurations are compared from two broad categories; pan-style and tubular reactors. In general, it was concluded that there are both heat and mass transport issues within pan-style and non-uniform diameter tubular reactor configurations and that these should be avoided if extraction of kinetic parameters is the goal. Uniform diameter tubular reactors are suitable for kinetic experimentation, but checks should be made using the dimensionless analysis discussed in this work.