Fluid Velocity Research Articles

Thermal analysis in Darcy-Forchheimer hybrid nanofluid through a Riga plate: An ANN optimization

In the present study, a double-hybrid nanofluid's Darcy-Forchheimer flow behavior over a Riga plate with the presence of radiation and heat source impacts is examined. Two distinct nanoparticles as Silicon Carbide (SIC), and Graphite (C) with a base fluid of Ethylene glycol (C2H6O2) are taken into consideration. The model of Cattaneo-Christov heat flux is discussed in the energy and mass equation. The symmetry variables are utilized to remodel the boundary conditions and governing flow models into non-linear ordinary differential equations. The redesigned ordinary differential equations are numerically computed using bvp4c in MATLAB. Graphical representations are used to study how distinct parameters create variations in the concentration, temperature, and velocity profile. The present study shows that the velocity profile decreases with an upsurge in the Hartmann number. The current analysis determined that the fluid velocity declines and the Forchhiemer number (Fr) increases. The fluid concentration increases when temperature temperature-dependent coefficient (B) rises. The significance of emerging parameters on skin friction, Nusselt number, and Sherwood number are computed in tabular shape. Artificial neural networking (ANN) is applied to optimize physical quantities of data, by training, validation, and testing, to check the accuracy of the data.

Air speed and direction affect metabolic and thermoregulatory responses during walking and running in a temperate environment.

Revisiting classical experiments on the impact of air resistance on metabolic rate, we aimed to overcome limitations of previous research, notably: low participant numbers (n=1-3), highly turbulent wind, and confounding effects of rising body temperature. In a custom-built wind tunnel with reduced turbulence, 14 participants (8 males, 6 females) walked (5 km.h-1) and ran on a treadmill (70%V̇O2max) at 0, 2, 4 and 6 m.s-1 headwind or tailwind in a counterbalanced design, with rest-breaks between each exposure to avoid rises in body core temperature. Oxygen consumption (V̇O2) exhibited strong linear relationships versus wind direction, dynamic pressure and air speed squared(Vwr2), lower in magnitude for headwind than tailwind. A moderate linear relationship was observed between heart rate, wind direction, dynamic pressure and Vwr2. Below 4 m⸱s-1, the effect of wind was well within inter- and intra-individual variation and equipment uncertainty, and only at wind speeds ≥4 m⸱s-1 did the differences in physiological responses reach statistical significance. Our data indicate that at running speeds below 4 m⸱s-1 (14.4 km/h), indoor treadmill and outdoor running are comparable in terms of the metabolic impact of air movement relative to the person. However, this does not extend to the thermoregulatory effect of wind, with outdoor running providing a higher cooling rate due to the self-generated wind created during running. By removing the confounding impact of core temperature rises, the observed effects of headwind were lower and those of tailwind larger than observed previously. In the context of middle-distance running, headwind created by running at 21.5 km.h-1 would result in a 2.2% increase of V̇O2. A relative tailwind of the same speed would lead to a 3.1% reduction.

Theoretical investigation of thermal and mass stratification effects on unsteady flow across a vertical oscillating plate with periodic temperature variation and variable mass diffusion

AbstractThis research paper examines the combined effects of thermal and mass stratification on unsteady flow past a vertical oscillating plate with periodic temperature variation and variable mass diffusion. The Laplace transform technique is introduced to deal with the linear coupled parabolic equations satisfying initial as well as boundary conditions and obtained solutions in closed form for concentration, temperature, and velocity. For example, to find the Laplace transform of an exponentially ordered piece wise continuous function , one can uses the formula , t being the time and s is a parameter. In this study, we explore the effects of different factors such as plate amplitude, plate frequency, thermal Grashof number, and the mass Grashof number on the concentration, velocity, and temperature profiles and shows them graphically. We see a decline in the fluid's velocity for thermal and mass stratification. Most interestingly, in presence of higher temperature gradient, as the frequency of the oscillations increases close to the plate surface, the fluid velocity declines. The reason behind this is that the flow system has a plate with very high fluctuations. We have found that the fluid's temperature goes up while the concentration goes down when there is a decrease in the thermal stratification and a rise in the mass stratification.

Numerical performance of Hall current and Darcy-forchheimer influences on dissipative Newtonian fluid flow over a thinner surface

Present problem concerns may be found in a wide variety of various industries and can takes a shape of round toroid's, cones, cylinders, domes (Axisymmetric shape), and other shapes as well. When it comes to actual applications, they are represented by aerosol cans, submarine pressure hulls, cooling towers, offshore drilling rigs, radomes, nuclear reactors, and other similar objects. The aim of this research is to improve the performance of MHD flow using Darcy-Forchheimer, viscous dissipation, porous and a heat source. The viscous convective permeable flow flowing over a bullet-shaped item is examined. Using similarity transforms, the structure of nonlinear differential equations are converted into dimensionless ODEs. Employing bvp4c shooting technique to decrypt the findings. Influences of physical entities on velocity and temperature were sketched and briefly described. Physical behaviors of skin friction and heat transfer rates are explored. The fluid velocity drops for Eckert number Ec as ε < 1.0, and rises as ε > 1.0, The fluid velocity improves with Darcy-Forchhemier parameter Fr when stretching ratio ε < 1.0 or = 1 or >1.0. The enhancement of fluid temperature is observed with enhanced Ec. A enhance in the Darcy-Forchhemier parameter Fr associated with improvement in skin-friction. In the absence of viscous dissipation, hall current, porous and Dacy-Forchhemier influences, the outcomes are in splendid covenant with those of previous studies.

Evaluation of wavy wall configurations for accelerated heat recovery in triplex-tube energy storage units for building heating applications

Efficient thermal energy storage (TES) is crucial for integrating intermittent renewable energy sources and managing fluctuations in energy supply and demand. Among TES methods, latent heat TES (LHTES) using phase change materials (PCMs) is highly promising due to its high energy storage density and nearly isothermal operation during phase transitions. However, the inherently low thermal conductivity of PCMs hinders heat transfer rates, negatively impacting charging and discharging performance. This study investigates novel wavy channel geometries for the PCM container in a triplex-tube LHTES unit to enhance heat transfer and improve solidification rates during the discharge process. A comprehensive computational model based on the enthalpy-porosity method is developed to simulate the PCM (paraffin wax RT35) solidification inside wavy channels with sinusoidal, zigzag, and step-function profiles. The effects of channel geometry, heat transfer fluid (HTF) velocity, and inlet temperature on solidification rate and heat recovery are systematically evaluated. Results demonstrate that the step-function geometry significantly accelerates solidification compared to straight channels, reducing discharge time by 65.1 % and increasing heat recovery rate by 147.9 %. Decreasing waviness width from 15 mm to 5 mm further reduces solidification time by 70.1 %, while increasing waviness height from 5 mm to 15 mm leads to a 74.4 % reduction. Moreover, increasing HTF flow from Re = 250 to 1000 enhances heat recovery by 92.3 %, and lowering inlet temperature from 20 °C to 10 °C improves it by 76.9 %. The findings provide valuable insights for designing efficient LHTES units with wavy channel geometries for renewable energy integration and thermal management applications.

Aerodynamic resuspension of irregular flat micro-particles

This study investigates the role of particle shape on the aerodynamic resuspension process of irregular flat micro-particles on a substrate. We propose that these particles resuspend at higher velocities than spherical ones of the same size under the same aerodynamic forces. Two sets of data are analyzed to test the argument. One from experiments we conducted using crushed glass particles (ranging from 80 μm to 300 μm) and another from published data on RDX explosive residue particles (sized between 10 μm and 25 μm) by other researchers.We particularly analyze the shape factors of the particles used in the experiments and introduce them into a Monte Carlo (MC) simulation model. The probabilities for the time evolution of the resuspension process are calculated through a Markov chain of states. The transition probabilities entail the balance between the forces and moments involved in the mechanisms for particle detachment from the surface.The particle resuspension rate as a function of the fluid velocity is evaluated both experimental and numerically. Additionally, we assess the removal efficiency for different particle size ranges whenever possible.Both experimental and numerical results demonstrate that the resuspension fraction of irregular flat particles is significantly lower than for equally sized glass microspheres under the same conditions. Simulations corroborate previous experimental findings, indicating that smaller irregular particles exhibit higher removal efficiency. According to the MC model results, irregular particles detach by sliding rather than rolling.

Analysis of MHD third-grade hybrid nanofluid model in Darcy-Forchheimer porous medium: Evaluation of the thermal performance of [formula omitted]-[formula omitted] cylindrical nanoparticles dispersed in ethylene glycol fluid

Researchers and scientists became interested in the newly developed idea of hybrid nanofluids because of their exceptional thermal conductivities, which resulted in enhanced thermal performance. These fluids have a wide range of uses in the industrial and technical fields. This novel class of fluids is playing a vital role in solar energy, automotive industry, cooling of the machine and manufacturing, heating and ventilation systems, electronic cooling, nuclear systems cooling, biomedical fields, space, ships, and defense systems. In light of the physical significance of the above-mentioned class of fluids, the current investigations are carried to examine the thermal performance of the mixture of cylindrical shaped aluminum oxide Al2O3 and copper Cu nanoparticles suspended in ethylene glycol using third-grade non-Newtonian fluid flow model. The fluid flow is induced by the stretching of the permeable sheet in exponential manner that is embedded in a Dacry-Forchheimer porous medium. The effects of Lorentz force applied normal to the flow and suction impacts have been incorporated in the current proposed model. The solutions of the flow model transformed to ordinary differential equations are computed using MATLAB built-in solver bvp4c. The solutions are presented in graphical representations. Graphical solutions reflect that fluid velocity slows down by growing the volume fractions of the nanoparticles. Increasing values of viscoelastic parameters reflect that there is a reduction in velocity and intensification in profiles of temperature and concentration have been noted. Rising values of cross-diffusion parameter is leading to the reduction in magnitude of velocity, and augmenting behavior of temperature and concentration has been seen. Observations indicate rising third-grade fluid parameter and porosity parameter lead to reduction in velocity. Increasing Schmidt number gives reduced Sherwood number, and magnetic field parameter improves the rate of hear transfer (Nusselt number) and skin friction coefficient for both Al2O3/ethylene glycol nanofluid and Al3O3-Cu/ethylene glycol-based hybrid nanofluid. The suggested model's validity is confirmed through comparison with previously released findings. Additionally, a grid independence test (sensitivity analysis) has been performed to verify the accuracy and verification of the numerical model.

Enhanced heat transfer in viscoelastic fluids with periodic magnetic fields and dusty nanoparticles between two parallel plates under thermal radiation

Exploring the intricate relationship between periodic magnetic fields and dusty nanofluids within one-dimensional, unidirectional frameworks shows great potential for advancing precise control within microfluidic devices and bolstering heat transfer efficiency in nanotechnology realms. In this study, we delve into the impact of heat transfer and periodic magnetic fields on viscoelastic nanofluids laden with dust particles, confined between two parallel plates. The flow dynamics are instigated by buoyancy forces, with due consideration given to heat transfer phenomena. Employing partial differential equations, we model the flow behavior, and through the application of the Poincaré-Light Hill Technique, we attain exact solutions. Graphical representations elucidate the temperature and velocity profiles, revealing the nuanced influences of various parameters. Utilizing Mathcad-15, we generate visual depictions of the fluid and dust particle distributions. Furthermore, our analysis delves into critical fluid attributes vital for engineering applications, including skin friction and heat transfer rates, which are comprehensively examined and tabulated. This encompasses the evaluation of heat transfer rates at the wedge surface, alongside the resultant influence on surface viscous drag forces. Our findings indicate that magnetic parameters induce reductions in both base fluid and dusty particle velocities, alongside the emergence of periodic motion under the influence of periodic magnetic fields. Periodic magnetic fields generate electrical power in induction generators widely used in wind turbines, hydroelectric power plants, and other renewable energy sources.

Influence of quantum correction on the Schwarzschild black hole polarized image

Using a model of an accretion disk around a Schwarzschild black hole, the analytic estimates for image polarization were derived by Narayan et al. (Astrophys J 102:912, 2021). Recently, the EHT team also obtained polarization images of the Sgr A∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{*}$$\\end{document} and measured both linear and circular polarization (Astrophys J Lett 964:L25, 2024). We find that quantum correction effects can also influence polarization information. Considering the quantum corrected Schwarzschild black hole (Kazakov–Solodukhin black hole), we derive the polarization intensity of the target black hole and investigate polarization images under different parameters. It is found that a larger quantum deformation leads to an expansion of the polarization region, while the polarization intensity value decrease. Under different observation angles, magnetic fields, fluid direction angles, and fluid velocity conditions, we also derive polarization images of corrected black holes. These key indicators not only affect the intensity of polarization but also the direction of polarization. We establish the relationship between polarization intensity and quantum correction deformation parameters, revealing a gradual decline in polarization intensity with reduced radius and an anti-polarization behavior induced by the progressive increase in deformation parameters at a constant radius. Our analysis may provide observational evidence for quantum effect of general relativity.

Renal handling of albumin in rats with early stage diabetes: A theoretical analysis.

In early diabetic nephropathy (DN), recent studies have shown that albuminuria stems mostly from alterations in tubular function rather than from glomerular damage. Several factors in DN, including hyperfiltration, hypertrophy and reduced abundance of the albumin receptors megalin and cubilin, affect albumin endocytosis in the proximal tubule (PT). To assess their respective contribution, we developed a model of albumin handling in the rat PT that couples the transport of albumin to that of water and solutes. Our simulations suggest that, under basal conditions, ∼75% of albumin is retrieved in the S1segment. The model predicts negligible uptake in S3, as observed experimentally. It also accurately predicts the impact of acute hyperglycaemia on urinary albumin excretion. Simulations reproduce observed increases in albumin excretion in early DN by considering the combined effects of increased glomerular filtration rate (GFR), osmotic diuresis, hypertrophy, and megalin and cubilin downregulation, without stipulating changes in glomerular permselectivity. The results indicate that in isolation, glucose-elicited osmotic diuresis and glucose transporter upregulation raise albumin excretion only slightly. Enlargement of PT diameter not only augments uptake via surface area expansion, but also reduces fluid velocity and thus shear stress-induced stimulation of endocytosis. Overall, our model predicts that downregulation of megalin and cubilin and hyperfiltration both contribute significantly to increasing albumin excretion in rats with early-stage diabetes. The results also suggest that acute sodium-glucose cotransporter 2 inhibition lowers albumin excretion only if GFR decreases sufficiently, and that angiotensin II receptor blockers mitigate urinary albumin loss in early DN in large part by upregulating albumin receptor abundance. KEY POINTS: The urinary excretion of albumin is increased in early diabetic nephropathy (DN). It is difficult to experimentally disentangle the multiple factors that affect the renal handling of albumin in DN. We developed a mathematical model of albumin transport in the rat proximal tubule (PT) to examine the impact of elevated plasma glucose, hyperfiltration, PT hypertrophy and reduced abundance of albumin receptors on albumin uptake and excretion in DN. Our model predicts that glucose-elicited osmotic diuresis per se raises albumin excretion only slightly. Conversely, increases in PT diameter and length favour reduced albumin excretion. Our results suggest that downregulation of the receptors megalin and cubilin in PT cells and hyperfiltration both contribute significantly to increasing albumin excretion in DN. The model helps to better understand the mechanisms underlying urinary loss of albumin in early-stage diabetes, and the impact of specific treatments thereupon.

A novel solar power generation hybrid system comprising evacuated U-tube solar collector and thermally regenerative thermocapacitive cycle

While solar energy offers a promising solution for sustainable energy, there’s a continuous drive to explore alternative methods of solar power generation. This paper introduces a novel solar power generation hybrid system that merges an angle-independent evacuated U-tube solar collector (EUSC) with a thermally regenerating thermocapacitive cycle (TRTC). Under AM 1.5 conditions, the hybrid system is anticipated to achieve a power density of 44.33 W m−2, accompanied by an efficiency of 4.43 %, underscoring its great prospect for practical applications. To unlock the performance potential, considerable parametric studies are conducted to find out diverse strategies to boost the hybrid system’s efficacy, encompassing the elevation of EUSC’s inlet temperature, reduction of external environmental temperature, moderation of fluid velocity within EUSC, and enhancement of thermal conductivity in the TRTC. Through meticulous optimization of thermal conductivity between TRTC and the environment, the hybrid system’s theoretical efficiency can attain a maximum of 9.38 %. A gradient-based local sensitivity analysis pinpoints that the EUSC’s internal fluid flow velocity is the most sensitive while the thermal conductivity coefficient between the TRTC and EUSC is the least sensitive. These results uncover key information critical for efficiently designing and operating the hybrid system.

On the dual diffusion flow of Powell–Eyring hybrid nanofluid with motile microorganism and non-uniform heat source using Darcy–Forchheimer model

This communication elaborates the rheological behavior of bioconvection flow of Powell–Eyring hybrid nanofluid over a stretchable heated cylinder embedded in Darcy–Forchheimer porous medium. The single and two-phase nanofluid models are used as mixture model by taking volumetric friction and dual diffusion of injected nanomaterial’s, while the Buongiorno model takes the dual diffusion of nanomaterials, allowing us to evaluate the thermophoresis and Brownian diffusion properties. The governing equations are solved with an efficient Runge–Kutta–Fehlberg numerical technique. The effects of appropriate parameters on flow, temperature, concentration, and motile microorganism. Our findings reveal that the fluid velocity increases with curvature parameter, while detract with Darcy and porosity parameter. Temperature is increasing function of Brownian, thermophoresis and heat source parameters. The concentration and motile profile increases with curvature parameter. An escalating trend for energy and mass transport was seen against curvature and thermophoresis parameter. Higher values of Curvature and Schmidt number depict positive impact on nanoparticle concentration, while the results for chemical reaction are conflicting. An increasing value of Brownian and thermophoresis parameters promote higher temperature. The temperature and thermal boundary layer thickness are also affected by the heat source and sink parameters in opposite manner.

Melting heat transfer and irreversibility analysis in Darcy-Forchheimer flow of Casson fluid modulated by EMHD over cone and wedge surfaces

The present mathematical model analyses the melting heat transfer and irreversibility in Darcy-Forchheimer flow of Casson fluids modulated by the electroosmosis and magnetohydrodynamic mechanisms over the wedge and cone surfaces. The effects of thermal radiation, thermal buoyancy and heat generation/absorption are taken into consideration. Appropriate similarity transformations are utilized to establish a system of ordinary differential equations which are non-linear. The model has been numerically simulated using shooting approach in conjunction with the fourth order Runge-Kutta method under the bvp4c tool of MATLAB. Numerical results are computed for fluid velocity, fluid temperature, Nusselt number and Bejan number for analysing the fluid flow behaviour and heat transfer characteristics for the Casson fluid. A comparative analysis is performed to determine the irreversibility and heat transfer in the absence and presence of melting parameters, respectively. Variations in skin friction coefficient, local Nusselt number and Bejan number have also been examined under the effects of key parameters. Key findings of the present study indicate enhanced velocity distribution with increasing zeta potential and electric field parameters, while it diminishes with higher Prandtl number and Forchheimer terms. Moreover, fluid temperature reduces with rising zeta potential, while the Bejan number escalates with greater thermal radiation in the core region of geometries. The findings of the model may be useful in various applications of thermal systems.

Entropy generation on inclined magnetize double diffusive convective transportation of radiative Casson nanofluid in porous medium with source/sink

This research intends to investigate the entropy generation on the magnetized double diffusive heat and mass transfer flow of the Casson nanofluid under the influence of an inclined magnetic field in a porous medium. Additionally, the combined impact of heat absorption, chemical reaction, Brownian diffusion, source/sink, and thermophoresis phenomena is also taken care of. The fluid flow involves convective boundary conditions for both temperature and concentration instead of a constant value at the surface. The flow-regulating system involved nonlinear PDEs that are turned into nonlinear systems of ODEs by using scaling variables and then solved this system numerically in Matlab using the bvp4c strategy, which is a collocation technique based on the Lobatto 3-stage FDM algorithm. Graphical representations illustrate the behavior of fluid velocity, entropy generation, concentration, and temperature in response to changes in flow parameters. Physical quantities like skin friction coefficient, Nusselt number, and Sherwood number have been investigated using 2D and 3D plots. Here, we concluded that the inclined magnetic field decimates the flow velocity gradually and greater values of the magnetic field lead to an increased rate of entropy generation. Furthermore, it has been noted that the temperature profile improves as the Brownian motion of particles increases, and the distribution of energy also enhances with larger values of the thermophoresis. The obtained key findings are discussed in a physical manner using graphic representation.

Determine velocity of fluid in curved micro channels fabricated with 3d printing (SLA)

The study investigated fluid dynamics in curved microchannels, exploring 3D printing parameters, channel geometry, and fluid properties, crucial for applications in medicine and energy. It highlighted the importance of microfluidics in handling small samples and enabling rapid analysis, stressing the need for precise measurement techniques to validate fluid velocity. Using 3D printing for microchannel design illustrated their utility, with microscopy aiding flow behavior comprehension. The research aimed to validate fluid velocity, covering technology analysis, microdevice design, fabrication, and measurement methodologies. It successfully fabricated microdevices confirming fluid movement via capillarity, revealing the relationship between channel radius and flow velocity. Distinct flow velocity patterns were observed, vital for design optimization. The study affirmed capillary flow as a spontaneous phenomenon, with fluid velocity variations along curved microchannels consistent with mass conservation principles in incompressible flows.

Honeycomb-configured dissipative nanofluid flow within a squeezed channel with entropy generation: regression and numerical evaluations

PurposeNanosized honeycomb-configured materials are used in modern technology, thermal science and chemical engineering due to their high ultra thermic relevance. This study aims to scrutinize the heat transmission features of magnetohydrodynamic (MHD) honeycomb-structured graphene nanofluid flow within two squeezed parallel plates under Joule dissipation and solar thermal radiation impacts.Design/methodology/approachMass, energy and momentum preservation laws are assumed to find the mathematical model. A set of unified ordinary differential equations with nonlinear behavior is used to express the correlated partial differential equations of the established models, adopting a reasonable similarity adjustment. An approximate convergent numerical solution to these equations is evaluated by the shooting scheme with the Runge–Kutta–Fehlberg (RKF45) technique.FindingsThe impression of pertinent evolving parameters on the temperature, fluid velocity, entropy generation, skin friction coefficients and the heat transference rate is explored. Further, the significance of the irreversibility nature of heat transfer due to evolving flow parameters are evaluated. It is noted that the heat transference rate performance is improved due to the imposition of the allied magnetic field, Joule dissipation, heat absorption, squeezing and thermal buoyancy parameters. The entropy generation upsurges due to rising magnetic field strength while its intensification is declined by enhancing the porosity parameter.Originality/valueThe uniqueness of this research work is the numerical evaluation of MHD honeycomb-structured graphene nanofluid flow within two squeezed parallel plates under Joule dissipation and solar thermal radiation impacts. Furthermore, regression models are devised to forecast the correlation between the rate of thermal heat transmission and persistent flow parameters.

Flow Field Simulation of a Hydrogeological Exploration Drill Bit for Switching between Coring Drilling and Non-Coring Drilling

Drilling is one of the most commonly used techniques in hydrogeological exploration and is employed to obtain rock samples and create boreholes. During conventional drilling, it is necessary to raise all the drilling tools in the borehole when switching between coring drilling and non-coring drilling, which causes large auxiliary operation time consumption and poor drilling efficiency. Based on the structure of wireline coring tools, a large diameter modular drill bit was designed to switch between coring drilling and non-coring drilling without lifting the whole set of drilling tools. In the COMSOL simulation environment, a simulation model of the modular bit was constructed. Drilling fluid velocity and pressure characteristics flowing through the modular bit were studied. According to the analysis results, with the same input flow rate, similar velocities and lower pressure loss can be obtained in non-coring drilling as with the coring bit, and thus drilling cuttings can be removed effectively even if there are more cuttings produced in non-coring drilling than in coring drilling for a borehole drilled at the same diameter. When the outside diameter of the modular bit is 216 mm, the recommended clearance value is 9 mm or 10 mm in order to obtain lower pressure loss and larger diameter core. To generate low pressure loss and ensure bit strength, a layout with four nozzles on the internal non-coring bit is recommended. The modular bit enables fast switching between coring drilling and non-coring drilling without raising the drilling tools. The simulation model can be used for drilling parameter selection and drill bit optimization.

Microgravity analysis of periodic oscillations of heat and mass transfer of Darcy-Forchheimer nanofluid along radiating stretching surface with Joule heating effects

Reduced gravity impact on mixed convection flow plays a significant role for designing of electric-generating plants in space, unwanted effects of free convection, thermodynamic stability, space devices, surface tension and movement of nanoparticles. The novelty of present work is to find the impact of reduced gravity, Joule heating and thermal radiations on Darcy Forchheimer magnetized flow of nanofluid along the stretching porous sheet. The variable gravity is assumed as temperature dependent with maximum density and maximum density. The governing model is converted into convenient model to find physical thermo parameters. The primitive steady, real and imaginary equations are formed by using stokes and primitive transformations. To make programming algorithm in FORTRAN Lahey-90/95, the primitively terms are deduced in each equation. For tabular and numerical findings of steady velocity, temperature and concentration, the implicit form of finite difference approach is applied with Gaussian elimination method. The fluctuating skin friction, fluctuating heat transfer and fluctuating mass transfer are displayed by using steady outcomes in main formula. It is found that the magnitude of fluid velocity enhances as magnetic force, reduced gravity and Darcy Forchheimer parameter enhances. It is concluded that temperature distribution decreases as magnetic force enhances. It is noted that oscillating frequency in skin friction and heat transfer enhances as Schmidt number enhances. It is found that the maximum fluctuating layer in heat and mass transfer enhances as Prandtl number enhances.

Sensitivity analysis and enhanced EMHD performance of unsteady ferrite-water hybrid nanofluid on a Riga plate with variable magnetization and heat generation

In connection to the various applications on energy conservation, fluid-based electronics; the coupling of electro-magnetic along with heat generation presents their significant approach. Therefore, the current investigation aims at analyzing the role of ferrite-water hybrid nanofluid in an Electro-Magnetohydrodynamics (EMHD) system. However, it utilizes the flow over a Riga plate with the variable properties of magnetization with the inclusion of thermal radiation and heat generation. Elucidating the influence of ferrite nanoparticles, the unsteady nature of the system addressed various properties of nanofluid. The system of equations is handled numerically adopting shooting-based fourth-order Runge-Kutta technique followed by similarity rules those are used to transformed the governing phenomena into ordinary. To maximize the EMHD efficiency, an optimization framework is employed using response surface methodology (RSM). However, to validate the work a hypothetical test is conducted with the help of analysis of variance (ANOVA). Through sensitive analysis, the key factors for the response of heat transfer rate are identified. Further, the measure outcomes of the results are; the inclusion of the ferrite nanoparticles with the increasing EMHD parameter the fluid velocity augments in magnitude. Further, increasing radiation the surface of the sheet became cool and it radiate from the surface region for which the fluid temperature boosts up.

An evaluation of microphysics in a numerical model using Doppler velocity measured by ground-based radar for application to the EarthCARE satellite

Abstract. The Cloud Profiling Radar (CPR) of the Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) has a new capability to observe the Doppler velocity related to the vertical air motion of the terminal velocity of hydrometeors. The new observation from space will be used to evaluate and improve the model. Before the launch of EarthCARE, we need to develop a methodology for using the CPR data for model evaluations. In this study, we evaluated simulated data by a stretched version of the global non-hydrostatic model over Japan with a ground-based CPR using an instrument design similar to the EarthCARE CPR. We chose two cases with different precipitation events in September 2019 using two cloud microphysics schemes. We introduced the categorization method for evaluating microphysics using Doppler velocity. The results show that the liquid and solid phases of hydrometeors are divided in Doppler velocity, and the model's terminal velocities of rain, snow, and graupel categories can be evaluated with the observation. The results also show that the choice of microphysics scheme has a more significant impact than the dependence on precipitation cases. We discussed the application of the EarthCARE-like simulation results using a satellite simulator.