Convective Rate Research Articles

Theoretical Examination of the Volume Concentration and Nanoparticles Density Influence on the Convective Heat Transfer Enhancement of Nanofluid in 2D Cavity Including the Square Heater

Nanofluid is one of the solutions of heat transfer, which can apply in devices fields as nuclear power, Nano-electronics systems, and solar fluid heating. In this work, the natural convection of Cuwater nanofluid is examined using the Lattice Boltzmann Method (LBM) as a mesoscopic approach. The main objectives of this work are to study the performance and pattern of Cu-water nanofluid and to demonstrate that the nanofluids behave differently while improving their energy transfer compared to pure fluids. The set goal was achieved by solving the tasks: based on the streamlines and isotherms profiles to demonstrate how the convection process and temperature gradients improve. Also, conducting study on heat transfer of nanofluid by calculate the Nusselt number. Depending on the nanoparticle volume percentage, the Grashof number Gr , and the hot obstacle have a significant impact on the convection flow and rate of heat transfer. The most important result is the enhancement of heat transfer with the increasing of volume fraction for a particular Grashof number, also it improves with the rising of Grashof number for a particular nanoparticles volume fraction. Therefore, the aspect ratios of the enclosure have played a significant part in Nusselt number variation. In addition, we found that the Nusselt number avg Nu is higher in the case of cavity without hot obstacle more than for cavity with hot obstacle, so the heat transfer improves in the case of cavity without hot obstacle. The significance of the obtained results consists that the nanofluid is one of the ways to improve heat transfer due to its specific characteristics and properties.

Quantifying the contributions of powder mixing mechanisms using a combined proper orthogonal decomposition and analysis of variance approach

In manufacturing, powder mixing processes are vital for ensuring product quality. The mixing progress and efficiency are determined based on the fundamental convection and diffusion mechanisms. While mixers are believed to have a unique primary mixing mechanism, recent findings from our group have verified that the main mechanism can change as the mixing progresses. The transitions were successfully captured using a new method incorporating proper orthogonal decomposition (POD) into the discrete element method simulation, proving POD as a valuable tool for mechanism identification. Nevertheless, the existing POD method cannot quantitatively evaluate these mechanisms, hindering a comprehensive analysis of their magnitudes and transitions. This study combines analysis of variance (ANOVA) with POD to solve the problem, establishing a POD-ANOVA framework to quantify the degree of contribution of the mechanisms. The capability of POD-ANOVA is assessed in the transverse mixing of a rolling drum. For a quantitative evaluation of the mechanism magnitudes, POD-ANOVA is performed over the entire mixing process (denoted as Standard POD-ANOVA). The convection and diffusion rates are then derived from the overall mixing rate. Validations show that the two rates corroborate well with common indicators of mechanism intensities. Furthermore, Standard POD-ANOVA is applied over sequential time domains to track mechanism transitions; however, it is found to be insufficiently precise. Thus, a new time-windowing POD is implemented, leading to Windowed POD-ANOVA. Over short time windows, the improved method can effectively quantify the transitions. Consequently, the proposed methods enable a quantitative evaluation of powder mixing mechanisms scientifically for the first time.

Squeezing flow in the existence of carbon nanotubes past a Riga plate

Squeezing or squeeze flows have tremendous applications in applied fields, like engineering, biomedical sciences and rheological studies. This paper demonstrates the squeezing flow of kerosene-based nanoliquids between parallelly aligned plates, with a Riga-type fixed lower boundary. The effects of dispersing two types of copper-functionalized carbon nanotubes (CNTs), single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs) are examined. Using appropriate transformations, a self-similar ordinary differential system is derived from the governing model of partial differential equations and substantial boundary conditions. Using the homotopy analysis method (HAM) and the [Formula: see text] package, analytical and numerical estimates are obtained, respectively. For higher values of the squeezing parameter, dimensionless temperature increases, while velocity patterns are upside-down. Moreover, increments in dimensionless parameters representing Riga constituent width, modified Hartmann number, nanoparticle concentration and radiation parameter improve heat transfer rates and thermal boundary layer thickness, however, adversely affect velocity. Despite enhanced friction effects, numerical results show that the Nusselt number increases as nanoparticle loads and radiation parameters increase. This suggests that convection rates are improved over conduction rates. Excellent agreement is found between analytical and numerical evaluations. Apparently, it is noticed that MWCNTs perform better than SWCNTs.

The velocity field behavior and the nature of deposition of microparticles in a thin layer of colloidal solution at wall heating from one and two laser beams

To date, heat transfer, convection and particle deposition have been mainly investigated for the case of homogeneous wall heating. Convection and particle deposition during local heating, when there are one or more local heating sources, have not been practically studied. Experimental studies of free convection and particle deposition in a layer of colloidal solution have been carried out. Convection was created by heating the liquid using one and two laser beams. The colloidal solution consisted of water and microscopic TiO2 particles. The novelty of the work is the demonstration of the effectiveness of local heating in creating high rates of convection and particle deposition at low energy costs. With two-point laser heating, the convection rate is higher than with single-point heating. When using two laser beams, the Marangoni number increases in comparison with single-point laser heating. As a result, the Bo number becomes lower than the critical value and the stability of the velocity field increases. In contrast to single-point heating, the use of two laser beams does not change the vortex flow pattern with increasing layer height. The particle deposition rate is higher when using a single laser beam than when using two beams and is two orders higher than the deposition without convection. An expression linking the deposition rate with time, layer height and fluid velocity is derived. The obtained results on the use of local heating sources are applicable for enhancing convection, as well as in technologies for cleaning solutions from solid impurities.

Joint effect of air flow and substrate wettability on evaporation of a sessile droplet on a solid surface

We study the evaporation of microliter droplets of water on hydrophilic, hydrophobic, and superhydrophobic substrates subjected to airflow around them. While there is a large body of literature on diffusion-limited evaporation, evaporation in the presence of external convection is not fully-explored. We use side-view imaging and a custom-built flow channel to record the evaporating droplets from the side and develop an analytical model for evaporation in the presence of convection. Based on the droplet’s inlet flow velocity and wetted diameter, the maximum Reynolds number is 203. We quantify the time-variation of droplet volume, wetted diameter, and dynamic contact angle as a function of substrate wettability and airflow velocity. We found that the droplet lifetime decreases with the airflow, which is explained by the larger contribution of the convective mass loss rate compared to the diffusive mass flow rate computed by the model. Interestingly, the droplet lifetime is longer on a hydrophobic substrate due to the smallest area of liquid-gas interface among the three substrates for a given airflow. In general, evaporation occurs at constant contact radius (CCR) mode for hydrophilic surface in case of without flow and for all cases of airflow velocity. The CCR followed by constant contact angle (CCA) mode is observed for hydrophobic surface, and CCA followed by mixed mode is reported for superhydrophobic surface. The theoretical model reasonably predicts the measurements of different cases of airflow velocity and substrate wettability.

Spatiotemporal analysis and predicting rainfall trends in a tropical monsoon-dominated country using MAKESENS and machine learning techniques

Spatiotemporal rainfall trend analysis as an indicator of climatic change provides critical information for improved water resource planning. However, the spatiotemporal changing behavior of rainfall is much less understood in a tropical monsoon-dominated country like Bangladesh. To this end, this research aims to analyze spatiotemporal variations in rainfall for the period 1980–2020 over Bangladesh at seasonal and monthly scales using MAKESENS, the Pettitt test, and innovative trend analysis. Multilayer Perception (MLP) neural network was used to predict the next 8 years' rainfall changes nationally in Bangladesh. To investigate the spatial pattern of rainfall trends, the inverse distance weighting model was adopted within the ArcGIS environment. Results show that mean annual rainfall is 2432.6 mm, of which 57.6% was recorded from July to August. The Mann–Kendall trend test reveals that 77% of stations are declining, and 23% have a rising trend in the monthly rainfall. More than 80% of stations face a declining trend from November to March and August. There is a declining trend for seasonal rainfall at 82% of stations during the pre-monsoon, 75% during the monsoon, and 100% during the post-monsoon. A significant decline trend was identified in the north-center during the pre-monsoon, the northern part during the monsoon, and the southern and northwestern portions during the post-monsoon season. Predicted rainfall by MLP till 2030 suggests that there will be little rain from November to February, and the maximum fluctuating rainfall will occur in 2025 and 2027–2029. The ECMWF ERA5 reanalysis data findings suggested that changing rainfall patterns in Bangladesh may have been driven by rising or reducing convective precipitation rates, low cloud cover, and inadequate vertically integrated moisture divergence. Given the shortage of water resources and the anticipated rise in water demand, the study's findings have some implications for managing water resources in Bangladesh.

A newly designed BIPV system with enhanced passive cooling and ventilation

Nowadays, the application of renewable energies such as solar energy in the building sector has increased notably considering the adverse impacts of climate change on human life; hence many studies have focused on the application of photovoltaic panels in buildings. In the current study, a 3D computational fluid dynamics (CFD) model has been developed to evaluate the performance of a newly designed building-integrated photovoltaic (BIPV) system. Given the negative influence of overheating on the lifespan and performance of PV panels, their passive air cooling has been studied. Further, the potential of rooftop-mounted solar panels in passive ventilation of buildings by generating natural convective currents has been explored. The developed CFD model takes into consideration the effects of radiation, conduction, and buoyancy-driven natural convective currents generated by solar PV panels which are heated due to the exposure to solar radiation heat flux. The results suggest that applying a high surface emissivity for the part of the roof beneath the PV panels intensifies the natural convective currents which in turn provides better cooling for PV panels with higher cooling effects at higher solar heat fluxes. Up to a 34% increase in the convective mass flow rate and a 3 K decrease in the mean temperature of the panels were attained by modifying the emissivity of roof surface. Such a 3 K decrease in the operating temperature of the PV panels can enhance their efficiency and lifespan by about 1.56% and 21 %, respectively. Based on the operating conditions and system characteristics, the BIPV system yielded an air change rate (ACH) in the range of 3–13 which was considered to be highly prevalent in providing the required passive ventilation for a wide range of applications. It was also observed that the flow dynamics inside the building were affected by both the amount of solar heat load incident on the solar panels and the emissivity of the roof surface behind the panels.

Study of micro-scale flow characteristics under surface acoustic waves

As an effective tool for contactless manipulation of submicrometer scale objects, the controllability of acoustic streaming velocity and flow field morphology determines the accuracy of object migration and the completeness of three dimensional (3D) imaging. This paper proposes an equivalent acoustic streaming driving force model that is applicable to both two dimensional (2D) and 3D calculations and constructs a numerical method for submicrometer microsphere migration and rotation velocity in acoustic streaming. The results show that the relationship between the peripheral vortex size Lp/wc and the relative acoustic streaming velocity vas/vf satisfies Lp/wc = 0.125vas/vf0.36 under certain geometrical conditions. Reducing the spatial confinement and increasing the inter-vortex distance will increase the energy release efficiency, reduce the pressure gradient distribution and convective dissipation rates, increase the vortex intensity and radiation range, and consequently, increase the vortex characteristic size. In complex 3D vortex flow fields, suspended objects are affected by velocity distributions and exhibit motions such as cross-flow lines and rotation. For larger vortex structure sizes, full 3D imaging is more favorable due to the increased rotation speed and period of motion along the orbit of the submicrometer microspheres. This study helps us to reveal the modulation mechanism of acoustic streaming field flow characteristics, enrich the basic theory of alternating orbital motion and forces on objects in vortex structures, and provide guidance for acoustic flow-based contactless object manipulation.

Study of thermal convection in chemically reactive carbon nanotube suspension saturated in anisotropic porous enclosure

This study aims to investigate the influence of chemical reactions and anisotropic porous material on the convective instability, heat and mass transfer rate of water-based carbon nanotube suspension. Flow governing dynamics are modeled using the modified Brinkman–Buongiorno model. The effects of pertinent flow characterizing parameters such as chemical reaction parameter, porosity parameter, mechanical anisotropy parameter and thermal anisotropy parameter on the threshold of convection, heat and mass transport rate are discussed and compared for three types of enclosures: shallow, square and tall. The study concludes that nanoliquid suspended with single-walled carbon nanotubes has higher heat and mass transfer capability than the multi-walled carbon nanotubes when saturated in a tall porous enclosure and also tall enclosure allows the convection to set in earlier. Anisotropic effect and destructive chemical reaction delay the starting of convection. Further, it is observed that the heat transfer rate decreases with the chemical reaction parameter.

Thermal analysis of suspended single droplet evaporation measurements with a coupled lumped parameter model

The measurement data of single droplet evaporation experiments are often biased due to the extra heat input through the fiber suspension and the presence of thermal radiation in hot environments. This encumbers model validation for heat and mass transfer simulations of liquid droplets. In this paper, a thermal analysis of this measurement layout is presented with a coupled lumped parameter model, considering heat conduction through the suspension. The model was validated by experimental data from the literature and good agreements were found. The thermal analysis focused on fiber material and geometry, and thermal radiation properties. Calculations were performed on a broad range of ambient conditions for liquids with different volatility characteristics. Temporal squared droplet diameter- and temperature-profiles, furthermore, droplet stationary evaporation rate were used to characterize vaporization phenomena. The thermal balance of the droplet is dominated by the convective heat rate from the environment in the early stage of evaporation. The effect of heat conduction through the fiber becomes important at the end of the droplet lifetime when the droplet size is decreased. Temperature sensor suspension may seriously bias droplet temperature due to the larger thermal conductivity compared to quartz fiber. Large droplets in high-temperature environments show significant sensitivity to thermal radiation properties, which should be considered in measurements and model validation.

Investigation for improvement of discharging rate within a renewable energy storage system with adding nano-powders

Discharging process through a renewable energy unit in existence of nanoparticles as additives has been simulated numerically. The estimation of properties of working material (mixture of H2O and alumina) has been done via single phase technique. Model includes two equations dominated by conduction mode because the convective rate is negligible. FEM modeling has been verified based on utilized assumptions. With dispersing nanoparticles, the rate of heat release enhances and freezing time declines about 41.18 %. With increase in dp of alumina powders from 30 to 40, the period of process reduces around 19.96 %.

Experimental study on the heat flux profile upon the building facade of the window-ejected fire plume

The window-ejected fire plume with the excess fuel released outside the opening poses great threat to the building facade due to the hazardous heat flux. This paper investigates experimentally the temperature inside the compartment, convective- and excess- heat release rate, facade flame height and the heat flux profile upon the building facade of the under-ventilated window-ejected fire plume. A set of experiments are carried out with a compartment-facade model consisting of a 0.40 m reduced cubic compartment and a vertical facade. An opening with various sizes is set at the center of the sidewall of the compartment. The temperature inside the compartment, convective- and excess- heat release rate, facade flame height and the heat flux profile upon the building facade are measured and quantified by thermocouples, camera and heat flux gauge array upon the building facade of the under-ventilated window-ejected fire plume for various openings and heat release rates. The center line heat flux could be correlated well with the non-dimensional height normalized by the flame height involving the correction factor. A global model on the heat flux profile upon the building facade incorporating the aspect ratio of the opening, flame height and the convective heat release rate, is developed to describe the transverse heat flux evolution in a general dimensionless form, and the proposed model correlates the experimental data well. The obtained experimental data and proposed model provide a basic understanding of the heat/thermal impact on the facade of the window-ejected fire plume due to excess fuel diffusion combustion.

Thermal behavior of CMC solutions under simulation of radio frequency pasteurization

Pasteurization and enzyme-inactivation are an economical and convenient way to provide safety and shelf-life stability. However, long heating time and non-uniform temperature distribution are the main issues of traditional thermal processing for enzyme-inactivation. Because of the volumetric heating and high heating rate, radio frequency (RF) treatment is considered as one of the most promising physical enzyme-inactivating methods. A 6 kW, 27.12 MHz RF heating system was applied to explore the effect of cylindrical container dimension and solution concentration on the thermal behavior of high-viscosity liquid food. Carboxymethylcellulose (CMC) solution as a non-Newtonian fluid was selected as a model liquid food in this study. The target temperature for enzyme inactivation was 70 °C. The experimental results showed that the electrode gap, container length, and container diameter affected the heating rate and uniformity of the liquid food. Furthermore, when the concentration of CMC solution increased from 0.5% to 2.0%, the heating rate of the solution firstly increased and then decreased, while the heating uniformity index of the solution increased from 0.008 ± 0.001 to 0.056 ± 0.002. The simulation results showed that the higher electric field strength led to a higher heating rate, temperature, and velocity of natural convection of the solution at the ends of the container. Then, the recirculation zones from the ends to the center of the container were formed, which was diminished with the increasing concentration solution, resulting in the increased maximum temperature difference of solution. The results of this research may provide useful data for subsequent continuous flow studies and information on potential RF enzyme-inactivation in high-viscosity liquid foods.

Numerical Analysis of Convective Mass Transfer during Multi-Droplet Impingement on a Structured Surface in the Presence of an Adhered Liquid Film—An Application to Spray Etching of PCBs

Multi-droplet impingement is a fundamental aspect inherent to all kinds of technical spray processes which typically aim at enhancing the convective exchange of reagents or heat at the impinged surface. In this paper, the impingement of multiple droplets onto a structured surface is investigated by a comprehensive CFD model, which resolves the dynamics of the individual droplets and the film on a micro-scale level based on the Volume of Fluid (VOF) method. The considered surface topology includes cavities and is typical for protective masks used in the spray etching of Printed Circuit Boards (PCBs). The agitation of the liquid film in terms of the convective mass transfer rates across virtual horizontal evaluation planes is studied and the influence of film height and droplet impaction velocity is elaborated. Passive tracer tracking is employed to investigate the release and re-entrainment of fluid at the surface cavities. Two modes of mass exchange between the cavities and the main flow upon droplet impingement are identified, which are central inflow accompanied by lateral outflow (1) and lateral inflow with outflow at the opposing side (2). A statistical analysis of the allocation of tracer particles shows that high impaction velocities and low film heights correlate with an enhanced decay of tracer particles within the cavities. The susceptibility to re-entrainment is also reduced by high impaction velocities, whereas increased film heights are found to promote re-entrainment.

Gas Production Potential in Geothermal-Energy-Enhanced CH4–CO2 Swapping Processes

Carbon capture and storage has become a practice to reduce the greenhouse effect of carbon dioxide (CO2) on the global climate. Recent studies have generated increasing concerns about CO2 leakage from underground structures. This has called for more research on CH4–CO2 swapping in natural gas hydrate (NGH) reservoirs to lock CO2 in a solid state in underground structures. Because the CH4–CO2 swapping is too slow to be efficient, this study proposes to use geothermal energy to accelerate the process. This paper presents a technical feasibility analysis of using geothermal energy to assist CH4–CO2 swapping for simultaneously storing CO2 in NGH reservoirs and producing the dissociated natural gas. Mathematical models were developed to compute heat transfer from geothermal zones to NGH reservoirs. A case study was carried out using the data from an NGH reservoir in the Shenhu area, Northern South China Sea. The result of the case study indicates that heat conduction dictates the heat transfer process when the heat convection flow rate is less than 0.01 m3/s over a heat-releasing borehole length of 2,000 m. Heat convection can significantly accelerate the heat transfer inside the gas hydrate reservoir. The 15°C (designed gas hydrate dissociation temperature in the studied case) heat front will propagate to the upper and lower boundaries of the gas hydrate reservoir (39 ft or 12 m) in 220 days by heat conduction only. This time can be shortened to 140 days with the aid of a fluid convection rate of 0.005 m3/s. Geothermal heating can significantly increase the initial productivity of wells in heated gas hydrate reservoirs in CO2 swapping processes. When the gas hydrate reservoir is heated from 6 to 16°C, the fold of increase is expected to exceed five in the studied case. This study shows that CH4–CO2 swapping process using geothermal stimulation is a promising method for producing natural gas and locking CO2 permanently in NGH reservoirs. Further studies should first focus on investigations of the effect of CO2-hydrate formation on the CO2 mass transfer inside reservoirs.

Nanomaterial heat transfer within thermal porous system in presence of Lorentz force

A curved enclosure in attendance of MHD was evaluated in this article. Both outer cold and inner hot surfaces have curved shapes which boosts the convective rate. The impact of MHD in equations has been applied and there is one negative term is x direction if horizontal magnetic fields have been applied. Presence of such a field leads to generation of Lorentz force which prevents the nanofluid from moving faster. Such reduction in velocity with growth of Ha makes Nu decrease. Adding nanoparticles with greater “m” and φ can increase the convective flow. When Ra = 700, dispersing nano-powders can enhance the Nu in existence of MHD about 41.9%. When Ra = 150, Nu can improve about 12.01% if “m” is enhanced. Nu decreases around 40.1% with growth of Ha while it increases about 43.36% in existence of greater Ra.

Stefan problem coupled with natural convection: An application to dissolution process

This paper investigates the process of dissolution of a solute in a solvent placed in an horizontal concentric cylinder. The theoretical investigation solves a Stefan problem with phase transition due to natural convective flow. To realize the objective, the governing equation for the concentration distribution, stream function–vorticity form of the Navier–Stokes equation for the flow field, and a Stefan condition for calculating the timescale evolution of the front are coupled together with different parameters. These non-linear equations are solved using a stable and second-order accurate boundary-fitted alternating direction implicit scheme with first-order upwind difference approximation for convective terms. The numerical scheme is validated initially by applying it to solve a natural convection problem with no phase transition, for which benchmark solutions are available. The validated scheme is then applied to the chosen problem followed by a refinement study to obtain a reliable solution. The obtained results are used to analyze the effect of physical parameters such as the Stefan number (Ste), geometric aspect ratio of solute to fluid, the Rayleigh number (Ra) and the Schmidt (Sc) number on dissolution rates as well as the flow patterns. It is observed that the solute dissolution, without the temperature influence, mainly depends on the annulus gap width (L) and the convection rate. Additionally, it is also observed that, for the Rayleigh numbers greater than 105, the unit circular-shaped solute initially dissolves uniformly from the outer surface, but as the time progresses, due to the influence of laminar boundary layer flow around the solute, it changes into an egg-shape.

Reversed micellar-enhanced ultrafiltration removal of oil from concentrated phospholipids

The de-oiling of concentrated phospholipids through ultrafiltration (UF) enhanced by reversed micelles using a polyethersulfone (PES) membrane was examined. Phospholipids could form reversed micellar structures with larger molecular weights in non-polar solvents, which were significantly different from oils and solvents with smaller molecular weights confirming the feasibility of membrane separation. Under the conditions of membrane retentate molecular weight of 50 kDa, transmembrane pressure difference of 0.30 MPa, inlet crossflow velocity of 2.78 × 10−4 m·s−1, temperature of 333.15 K, phospholipid feed concentration of 26.12 kg·m−3% and cycle ratio of 20:1, the retentate phospholipid content and phospholipid yield were 84.97% and 96.4%, respectively, and the permeate flux was 4.65 × 10−6 m·s−1. Phospholipids increased the hydrophobicity of the membrane surface and promoted concentrated phospholipid de-oiling. Finally, a mathematical model was established based on the two-dimensional concentration polarization mechanism indicating that permeate flux was mainly controlled by the convective transfer flow rate.

Numerical investigation of thermal improvement of system in existence of nanofluid and magnetic force

The current article aims to simulate the promising influence of porous zones on treatment of working fluid within curved shaped containers under the impact of MHD. The MHD was applied in x direction which produces one negative source term in the y velocity equation. The features of base fluid have been improved with dispersing Al2O3 nanoparticles. The formulation based on Ψ was used to simplify the equations and finally the equations were solved via CVFEM. Results showed that dispersing nano-powders boost the convective rate about 39.34% in the presence of MHD. Increase in shape factor can make Nu increase about 11.46%. The applying MHD causes Nu to reduce about 54.93%. Augment of Ra makes Nu augments around 68.91%.

Downscaling Industrial-Scale Syngas Fermentation to Simulate Frequent and Irregular Dissolved Gas Concentration Shocks.

In large-scale syngas fermentation, strong gradients in dissolved gas (CO, H2) concentrations are very likely to occur due to locally varying mass transfer and convection rates. Using Euler-Lagrangian CFD simulations, we analyzed these gradients in an industrial-scale external-loop gas-lift reactor (EL-GLR) for a wide range of biomass concentrations, considering CO inhibition for both CO and H2 uptake. Lifeline analyses showed that micro-organisms are likely to experience frequent (5 to 30 s) oscillations in dissolved gas concentrations with one order of magnitude. From the lifeline analyses, we developed a conceptual scale-down simulator (stirred-tank reactor with varying stirrer speed) to replicate industrial-scale environmental fluctuations at bench scale. The configuration of the scale-down simulator can be adjusted to match a broad range of environmental fluctuations. Our results suggest a preference for industrial operation at high biomass concentrations, as this would strongly reduce inhibitory effects, provide operational flexibility and enhance the product yield. The peaks in dissolved gas concentration were hypothesized to increase the syngas-to-ethanol yield due to the fast uptake mechanisms in C. autoethanogenum. The proposed scale-down simulator can be used to validate such results and to obtain data for parametrizing lumped kinetic metabolic models that describe such short-term responses.