Effect Of Fluid Type Research Articles

Investigation of the immersion cooling system for 280Ah LiFePO4 batteries: Effects of flow layouts and fluid types

The widespread use of high-capacity LiFePO4 batteries (LFPB) is crucial for meeting the growing demand for energy storage systems (ESSs). This requires effective thermal management systems, and single-phase immersion cooling (SPIC) is emerging as a promising option due to its superior cooling capability. This paper investigates the effects of flow layout and fluid type on 280 Ah LFPB under SPIC through experimental and numerical analyses. Three flow layouts (opposite sides, same side, and jet impingement) are proposed, and six fluids are used for simulations. Results show that the jet impingement achieves the lowest temperature and pressure drop. During 1P discharge with DF1 flowing at 0.006 m/s, the maximum temperature, temperature difference, and pressure drop are 317.67 °C, 4.71 °C, and 0.09 Pa, respectively. Varying flow velocities within 0.006–0.053 m/s significantly impact battery temperature in the same-side layout. The volatility due to different fluid types, including CV,ΔP (pressure drop), CV,Tmax (maximum temperature) and CV,ΔT (temperature difference) are presented. As the flow velocity increases, CV,ΔP decrease by 35.9 %, 39.4 %, and 36.2 % for opposite sides, jet impingement, and same side, respectively. CV,Tmax increases with the P-rate, and the same-side layout has the lowest CV,Tmax, below 0.9 % at 0.5P and 0.6 % at 1P. This study emphasizes that the effect of fluid type should be considered in the design of flow layouts, especially at low flow rates. Experimental observation indicates that no ignition or explosion occurred during battery thermal runaway under SPIC. The maximum battery temperature during thermal runaway is 241.9 °C. This research provides valuable insights into SPIC application and fluid selection for ESS.

Experiment on Heat Exchanger Using Innovative Coils and Phase Change Material/MXene Nanofluids

The utilization of innovative coiled wire turbulators along with phase change material (PCM; improving heat capacity) or MXene (having good dispersion stability) dispersed nanofluid in tubular heat exchangers may boost performance; however, it has not been explored yet. In the current analysis, experimental research is done on various mono-nanofluids and hybrid nanofluids flowing in a double-pipe heat exchanger with tapered, coiled wire turbulators to examine the hydrothermal aspects. Four coiled wire turbulators (conventional helical, conversing tapered, diverging tapered, and converging–diverging tapered) and four nanofluids (Al2O3/water, PCM/water, Al2O3+PCM/water and MXene/water) are utilized in the heat exchanger with all possible combinations. The effects of fluid types, turbulator types, total nanoparticle volumetric fraction, and nanofluid volume flow rate are investigated. Two thermal parameters (heat transport coefficient and Nusselt number), two hydraulic parameters (drop of pressure and friction coefficient), and two hydrothermal parameters (ratio of heat transport coefficient and drop of pressure, and generation of entropy) are considered objective functions. The study reveals that the diverging tapered, coiled wire yields significantly higher performance as compared to the conventional helical coiled wire as an insert. MXene/water has higher thermal performance; however, PCM-dispersed hybrid nanofluid yields better hydrothermal performance than other studied fluids.

Numerical simulation of the dynamical behavior of a spinning cylinder partially filled with liquid

The flow pattern and transient response of a spinning cylinder partially filled with fluid are investigated in this paper. A two-dimensional finite element model of the fluid domain in the cylinder cavity is developed via the structured tetrahedral element. By using the volume of fluid model, the flow pattern of the liquid is examined numerically. Also, the effects of fluid type, rotating speed, and liquid height on the flow pattern are investigated. Then, the obtained fluid pressure exerted on the inner wall of the cylinder is considered as the input load, and transient dynamic analysis of the spinning liquid-filled cylinder is carried out. Finally, a comprehensive parametric study is conducted to evaluate the effects of liquid type, spinning speed, and fluid height on the dynamical behavior of the system. The results show that these parameters greatly influence the fluid flow pattern and dynamic characteristics of the spinning liquid-filled cylinder system.

Analysis of melting of phase change material inserted a block via impinging turbulent slot jet

PurposeThe purpose of this study is to do a numerical analysis of the jet to a body filled with phase change material (PCM). The melting of the PCM filled body was investigated by the hot jet flow. Four different values of the Reynolds number were taken, ranging from 5 × 103 = Re = 12.5 103. Water, Al2O3 1%, Al2O3 2% and hybrid nanofluid (HNF; Al2O3–Ag mixture) were used as fluid types and the effects of fluid type on melting were investigated. At 60 °C, the jet stream was impinged on the PCM filled body at different Reynolds numbers.Design/methodology/approachTwo-dimensional analysis of melting of PCM inserted A block via impinging turbulent slot jet is numerically studied. Governing equations for turbulent flow are solved by using the finite element method via analysis and system fluent R2020.FindingsThe obtained results showed that the best melting occurred when the Reynolds number increased and the HNF was used. However, the impacts of using alumina-water nanofluid were slight. At Re = 12,500, phase completion time was reduced by about 13.77% when HNF was used while this was only 3.93% with water + alumina nanofluid as compared to using only water at Re = 5,000. In future studies, HNF concentrations will change the type of nanoenhanced PCMs. In addition, the geometry and jet parameters of the PCM-filled cube can be changed.Originality/valueEffects of impinging jet onto PCM filled block and control of melting via impinging hot jet of PCM. Thus, novelty of the work is to control of melting in a block by impinging hot jet and nanoparticles.

Working fluid study for loop heat pipes

Loop heat pipes (LHPs) provide unique applications for high heat flux and long distance heat transfer. Working fluid aspects, including liquid charging ratio, type and fluid dynamics, in loop heat pipe is quite different as compared to conventional heat pipe. This paper will particularly endeavor to explain these differences, and provide optimal design conditions achieved via experimental study. Design considerations and operational aspects of LHP with respect to working fluid is evaluation and discussed in detail. Important thermal-fluid properties with respect to pressure-temperature relation and merit number are outlined for various heat transfer fluids to choose best option for given conditions. LHP with capillary evaporator, 25 mm diameter and 155 mm long, and heat transfer length ∼250 mm was designed to study and optimize different working fluid aspects including optimum working fluid range for different orientations, effect of fluid type on performance and operational dynamics of loop related to fluid (start-up, oscillations, hysteresis and buoyancy effects). Loop utilized copper containment, nickel wick and mainly water as working fluid. As an outcomes of this investigation, it has been concluded that liquid ratio in range of 40 to 60 % of loop volume provide optimum charge, for different orientations, with 50 % charge showing best thermal performance. In summary, considered working fluid type and optimized overall liquid amount, calculated by giving due consideration to volumes of different loop components, can help to get best performance from the loop systems.

Analysis of fluid flow states in viscometers in ansys software

Viscometers have multiple major applications in various areas of engineering, as the fluid flow is inherently connected to the properties of fluid viscosity. This paper substantively examines the fluid flow state over a capillary viscometer to examine the stability of such flow under the effects of various geometries (variations in tube length and cylinder base shape) of capillary viscometer, using a simulation model improved by means of the application of finite element software in Ansys 16 to depict the flow in the capillary viscometer. In this work, experimental measures were utilised and implemented to evaluate various fluid properties and to observe the effects of the geometrical shapes of the viscometer on the flow properties (pressure, velocity, and temperature) and the effect of fluid type on the vortex and fluid circulation during flow.

Log-based prediction of pore pressure and its relationship to compressional velocity, shear velocity and Poisson’s ratio in gas reservoirs; Case study from selected gas wells in Iran

A precise identification of pore fluid pressure (PP) is of great significance, specifically, in terms of drilling safety and reservoir management. Despite numerous work have been carried out for prediction of PP in oil reservoirs, but there still exists a tangible lack of such work in gas hosting rocks. The present study aims to discuss and evaluate the application of a number of existing methods for prediction of PP in two selected giant carbonate gas reservoirs in south Iran. For this purpose, PP was first estimated based on the available conventional log data and later compared with the PP suggested by Reservoir Formation Test (RFT) and other bore data. At the end, it has been revealed that while PP prediction is highly dependent on the type of litho logy in carbonates, the effect of fluid type is negligible. Moreover, the velocity correlations work more efficiently for the pure limestone/dolomite reservoirs compared with the mixed ones.

Hydrothermal irreversibility analysis based on multi-criteria assessment in a modified spiral piping system utilized in solar ponds

Present study provides a numerical simulation with experimental validation of the modified spiral piping system employed in solar ponds. The most important part of the solar ponds that plays a key role in its performance is its piping system, which has not been considered appropriately so far. To enrich this field, grooving the wall of the spiral piping system (which is considered to be placed at the lower convective zone (LCZ)) was adopted as an improvement mechanism. It is worth mentioning that in this innovative modification technique grooves were made in an annular form on the wall of spiral pipe with various spacing. Although made changes increases the extraction of heat from pond, it intensifies irreversibility to some extent. Therefore, various decisive parameters including distance between the grooves, depth of grooves, flow rate, fluid type, and inlet temperature (Pr) were considered to explore their contribution to entropy generation. Moreover, to find out which of Nu∗ (or Q) or S ’ gen outweighs the other one, the effect of said parameters analyzed based on the multi-criteria design concepts like η W − S and N H. Three different working fluid including water, ethylene-glycol, and therminol-55 were used at different inlet temperatures (283K, 303 K, and 323 K) to cover a Pr range of 3.35–744. The obtained results show that with increment of flow rate and the depth of grooves also decreasing the pitch of grooves increases entropy generation. The maximum increment of N H is about 26% when the depth of grooves is the highest and the pitch of grooves is the lowest. Results proved that, therminol-55 and ethylene-glycol are recommended when the inlet temperature goes up. The overall performance of solar pond is in a most desirable condition when η W − S = 0.125 . • Implementing a novel technique to modify the spiral piping system utilized in solar ponds. • Hydrothermal irreversibility analysis of the system to pinpoint adverse conditions in heat extraction. • The effect of fluid type, Re, Pr, and geometrical parameters were considered. • Evaluations were performed based on multi-criteria design concepts like η W − S and N H .

Experimental and numerical analysis on vibration features of typical external pipe in aero-engine

The aero-engine pipe vibration phenomenon is a serious complicated problem in engine structure design and application. In this paper, an experimental and computational study was implemented on the aviation straight and L-shape pipe vibration characteristics. The pipe vibration shape and natural frequency were obtained by both hammering and Finite Element Methods (FEM). Effects of fluid type, pressure and temperature were examined on pipe vibration characteristic parameters. The results show that the pipe vibrates along transverse and vertical directions. There are slight differences in pipe vibrating natural frequency in the two directions. The pipe experimentally natural frequency and vibration modes agree well with those obtained in FEM computation. The fluid type, pressure and temperature can change the pipe vibrating amplitude values, but cannot influence the pipe vibration modal characteristics. Varying fluid pressure and temperature can to some extent change the pipe natural frequencies.

Effect of Fluid Type and Multiphase Flow on Sand Production in Oil and Gas Wells

Summary Controlled laboratory experiments and some field studies have shown that the onset of sand production in gas wells differs from that in oil wells. Results from a general 3D sand-production numerical model are presented to explain the differences in the onset of sanding and sand-production volume for different fluids and under different flow and in-situ stress conditions. The sand-production model accounts for multiphase-fluid flow and is fully coupled with an elasto-plastic geomechanical model. The sanding criterion considers both mechanical failure and sand erosion by fluid flow. Non-Darcy flow is implemented to account for the high flow rates. The drag forces on the sand grains are computed on the basis of the in-situ Reynolds number. Both the intact rock strength and the residual rock strength depend on water saturation. Water evaporation (drying) resulting from gas flow is modeled using phase equilibrium calculations. The onset of sand production is compared for different fluid types (oil and gas). Model results are shown to be consistent with experimental observations reported in the literature. For example, the onset of sanding is observed at higher compressive stresses for gas wells as compared with oil wells. The primary mechanism for this is for the first time shown to be sand strengthening induced by evaporation of water. This effect is not observed in oil wells. The sand-production rate when non-Darcy effects are considered is lower than for Darcy flow. The reason for this is the lower fluid velocity (for the same drawdown) and, consequently, smaller drag forces on the failed sand grains. The effect of water breakthrough and water cut on sand production is studied from both mechanical and erosion perspectives. The model is shown to be capable of accurately predicting the onset of sanding and sand production induced by multiphase- and compressible-fluid flows, helping us to predict sanding issues in both oil and gas wells.

An Experimental Study on Conductivity of Unpropped Fractures in Preserved Shales

Summary A great deal of evidence shows that hydraulic fracturing creates a large surface area of induced unpropped (IU) fractures that are too small to accommodate commonly used proppants and that, subsequently, close during production (Sharma and Manchanda 2015). Because of their enormous surface area, IU fractures can play an important role in hydrocarbon production if they can remain open during production. Therefore, the conductivity of these IU fractures under different stress conditions and when exposed to different fracturing fluids is of great importance. In this study, core-scale IU fractures were created with preserved shale samples from the Eagle Ford and Utica formations. Samples with different mineralogies were selected to represent a broad cross section of representative samples. Great care was taken to ensure that the shale samples were preserved because large changes in shale mechanical properties caused by sample desiccation have been observed. The fracture conductivities of unpropped fractures created in each of the shale samples were measured as a function of closure stress by using nitrogen or brine. The unpropped fractures were exposed to several water-based fracturing fluids including neutral brine, alkaline brine (pH 11, 12), and acidic brine (pH < 1), with or without clay stabilizers. The effects of fluid type, pH, clay stabilizers, shale mineralogy, and cyclic stress on IU-fracture conductivities were investigated. Batch tests also were performed to study the change of mechanical properties and fines production caused by fluid-shale interaction. Our results show that unpropped fractures yielded conductivities that were 2 to 4 orders of magnitude lower than those of propped fractures, and were more susceptible to closure stress. Exposure to water-based fracturing fluids decreased the unpropped-fracture conductivity by one order of magnitude. The primary mechanism for the decrease was shale softening caused by exchange of water and ions between the native fluid of shale and the exposed fracturing fluid. Shale softening was observed in exposure to all brines tested, regardless of their pH. In addition to shale softening, fines generation also contributed to the reduction of unpropped-fracture conductivity when shales were exposed to alkaline or acidic brine. Amine-based clay stabilizers were able to control the unpropped-fracture conductivity impairment by reducing the amount of clay-based fines. However, they were not as effective at stabilizing nonclay fines. Shale mineralogy affected the unpropped conductivities in two ways: It controlled the mechanical properties of the native preserved shale, and also affected the fluid-shale interactions. A clear correlation was observed between mineralogy and stress dependence. Clay-rich samples showed the most stress sensitivity in the presence of water or brine at neutral pH, whereas the calcite-rich samples showed less stress sensitivity. High clay content also resulted in lower restored conductivity after cyclic stress. Mechanical properties of shale such as hardness and Young's modulus, before and after fluid exposure, strongly correlated with the mineralogy of shales. Unpropped conductivity was more sensitive to cyclic stress than propped conductivities, and it dropped by 80% after one cycle of closure stress between 300 and 4,000 psi of closure stress. Clearly, it is shown that water-based fracturing fluids can affect conductivities of IU fractures in shales significantly, and these impacts need to be considered in the selection of fracturing fluids.

Effects of fluid type and pressure order on performance of convergent–divergent nozzles: An efficiency model for supersonic separation

AbstractA deep analysis on the hydrodynamics of convergent–divergent nozzles is performed by changing the working conditions and fluid type. The nozzle geometry lowers the temperature of the flowing fluid, which contributes to condensation and phase change. The focus of this paper is to evaluate the nozzle performance and cooling capacity in terms of temperature, pressure, and gas type in a fixed geometry of Sajben Laval nozzle. The analysis has been conducted via a 2‐dimensional turbulent computational fluid dynamics simulation for illustrating the behavior of the fluid. A criterion for the nozzle performance is provided by prediction of exact shock wave position. An investigation on 6 different gas types demonstrates that heat capacity and thermal conductivity are the most rolling fluid properties of the nozzle performance. Furthermore, it is found that the shock wave position is unchanged during alteration of fluid type or pressure scale.A new model is provided for prediction of convergent–divergent nozzle performance in the supersonic conditions for dehydration of natural gas as a well‐known industrial application of the nozzles. The model is developed by the genetic algorithm as a multivariable optimization method.

Hysteresis effect on dynamic modeling of AFM heterogeneous dagger MC in the vicinity of sample using MCS theory in liquid

Biological applications of AFM in the liquid medium make the behavior of probe in the liquid medium very important to investigate. This study analyzes the effect of hysteresis and probe mass on the dynamics of AFM rectangular and dagger micro cantilevers (MC) in the liquid medium. To this end, the MCS theory was used for modeling the MC. The model considered the changes in the cross section and a zinc oxide piezoelectric layer between two electrode layers. The beam type of elements was selected and modeling was based on the finite element method (FEM) on the basis of Euler-Bernoulli beam theory. Fluid and the effects of its forces change the vibration behavior of the system. Simplified models have been proposed and used to implement the relationships. Several types of fluid were examined to determine the effect of fluid type on the frequency and time delay. Hysteresis effect causes a phase delay in the time response and a slight increase in the vibration amplitude in the liquid and the air media. The phase difference depends on the type of the medium in which it is placed; the more viscous and dense is the medium, the less the hysteresis effect will be.

Effect of Synthetic Hydraulic Fluid on Warm-Season Turfgrass

Synthetic hydraulic fluid, which was developed for turf equipment in 2005, was compared to traditional hydraulic oils for its potential to cause turf injury. Effects of fluid type, volume, and temperature on area of injury, percent necrosis, and time to healing were investigated at Edison College in 2005-2006 via three experiments on hybrid bermudagrass (Cynodon dactylon L. [Pers.] × C. transvaalensis Burtt-Davey) or seashore paspalum (Paspalum vaginatum O. Swartz). Synthetic fluid applied on container-grown ‘Tifeagle’ at 1.85 ml/cm2 caused minimal shoot necrosis that healed within 10 days, while hydraulic oils caused 100% necrosis of shoots. Synthetic fluid applied on putting greens in the field at a volume of 20 ml caused an average of 70 cm2 of injury with 17% necrosis after 5 days. Time to healing was 15 to 30 days. In contrast, hydraulic oils caused larger areas of injury with more necrosis and longer healing times. Increasing volume increased injury area for all fluids tested, but temperature had minimal effect. Increasing volume and temperature increased percent necrosis for synthetic fluid but not for hydraulic oils. Compared to hydraulic oils, synthetic fluid consistently caused less injury to warm-season turfgrasses and is a viable replacement for traditional hydraulic oil in turf management equipment.

Effect of Fluid Type and Microbial Properties on the Aerosolization of Microorganisms from Metalworking Fluids

Aerosolization of mist from metalworking fluids (MWFs) has been well characterized in previous studies. Much less is known about the aerosolization of microorganisms, although airborne microbial exposures at MWF sites have been associated with occupational respiratory symptoms and diseases. In this study, the effects of fluid type, microorganism concentration in the liquid, and the microbial species on the aerosolization of microorganisms from MWFs were tested. Three microorganisms were employed to represent different size and surface characteristics: Bacillus subtilis bacterial endospores (hydrophobic particles with aerodynamic diameter = 0.9 μm), Pseudomonas fluorescens bacterial vegetative cells (hydrophilic, 0.8 μm), and Penicillium melinii fungal spores (hydrophobic, 3.1 μm). The testing was first performed using a Collison nebulizer to aerosolize microorganisms from three fluids: water, semisynthetic MWF, and soluble oil. No significant difference in the aerosolization ratio (microbial concentration in the air normalized to the microbial concentration in the liquid) was observed among the three fluids. For all tested microorganisms, the concentration in the air increased proportionally with the increase of the microbial concentration in the liquid. The aerosolization ratio of B. subtilis endospores was greater than that of P. fluorescens cells and P. melinii spores. To explore the aerosolization of microorganisms from MWFs under the conditions that are closer to industrial settings, the tests were conducted with a MWF simulator (a laboratory-scale setup simulating the mist generation during grinding process). Simulator tests showed the same trend with respect to microbial aerosolization as those performed with the Collison nebulizer. This was further confirmed by a separate experiment, in which the Collison nebulizer and the MWF simulator were tested with liquids containing polystyrene latex (PSL) particles. As a result, our study showed that hydrophobic microorganisms were easier to aerosolize from MWFs than hydrophilic microorganisms and that increasing microorganism size was likely to result in decreasing aerosolization ratio.

Effect of Fluid Type and Microbial Properties on the Aerosolization of Microorganisms from Metalworking Fluids

Aerosolization of mist from metalworking fluids (MWFs) has been well characterized in previous studies. Much less is known about the aerosolization of microorganisms, although airborne microbial exposures at MWF sites have been associated with occupational respiratory symptoms and diseases. In this study, the effects of fluid type, microorganism concentration in the liquid, and the microbial species on the aerosolization of microorganisms from MWFs were tested. Three microorganisms were employed to represent different size and surface characteristics: Bacillus subtilis bacterial endospores (hydrophobic particles with aerodynamic diameter = 0.9 μm), Pseudomonas fluorescens bacterial vegetative cells (hydrophilic, 0.8 μm), and Penicillium melinii fungal spores (hydrophobic, 3.1 μm). The testing was first performed using a Collison nebulizer to aerosolize microorganisms from three fluids: water, semisynthetic MWF, and soluble oil. No significant difference in the aerosolization ratio (microbial concentration...

Abrupt Change of Wake Oscillation and Surface Character on Suppression of the Karman Vortex Street from an Elliptic Cylinder due to Positive Buoyancy.

Abrupt Change of wake oscillation and surface character and effects of fluid type on it are elucidated by numerical calculation on suppression of the Karman vortex street due to positive buoyancy from a heated elliptic cylinder submerged ill upward mainstream of mercury, air or water. Abrupt change in the buoyant wake from an elliptic cylinder occurs at two different Richardson numbers, i.e. one is the first critical Richardson number, Ritr, and the other the second one, Ric(>Riir). At Ritr, the mean coefficient of the shear stress and the mean Nusselt number decrease abruptly for mercury and air, but increase abruptly for water. At Ric, the Strouhal number decreases abruptly for mercury and air, but begins to decrease continuously for water. The above characters for water differ qualitatively from those for mercury and air.

Suppression of the Karman Vortex Street due to Positive Buoyancy. Cause and Effect of Fluid Type on Thermo-Fluid Pattern.

The cause and effect of fluid type on thermo-fluid pattern of the suppression of the isothermal Karman vortex street to a modified vortex street and a plume-like flow due to positive buoyancy in a circular cylinder wake with an upward freestream of mercury, air and water are made clear by solving numerically of the two-dimensional, laminar, time-dependent continuity equation, Navier-Stokes equations with the buoyancy term, and energy equation. For any type of fluid, the cause of the suppression is an extinction of wake vorticity ; shear layers increases and the wake vorticity decreases due to positive buoyancy. Behavior of the suppression is different each other in mercury, air and water, beacuse an increase of the wall vorticity and a decrease of the wake vorticity are different in those fluid.

Suppression of the Karman Vortex Street due to Positive Buoyancy. Effect of Fluid Type on Wake Oscillation and Surface Value.

Effect of fluid type on wake oscillation and surface value in suppression of the Karman vortex street due to positive buoyancy from a heated circular cylinder submerged in an upward mainstream is elucidated by numerical calculation of the Navier-Stokes equations with buoyant term and the energy equation for mercury, air and water flow. Numerical results are validated. The Strouhal number decreases abruptly at the critical Richardson number Ric, which can be regarded as the exact boundary between the regions of the transformed vortex street and the plume flow. The largest Ric is for water, the smallest is for air. The mean Nusselt number of water flow decreases abruptly at Ric. This is because that the local Nusselt number near the rear stagnant point decreases at Ric due to a formation of a twin vortex.

The Effects of Fluid Type and Viscosity on the Steady-State and Advancing Front Permeability Behavior of Textile Preforms

The effects of fluid type and viscosity on the permeability of both saturated and dry preforms were investigated. Fluids used were water, corn oil, and Epon 815, an epoxy resin. Preforms tested included style 162 E-glass, a plain weave E-glass fabric, and IM7/8HS, an eight harness satin carbon fabric. Two methods were used to measure the permeability of the textile preforms. The first, known as the steady-state method, measures the permeability of a saturated preform under constant flow rate conditions. The second, denoted the advancing front method, measures the permeability of a dry preform to an advancing fluid. Results from the two methods showed that fluid viscosity had no significant influence on the permeabilities of the two fabrics. Steady-state and advancing front permeabilities for the warp direction of the two fabrics were similar. In addition, advancing front permeability values were found to be similar for different fluids over a wide range of values for the capillary number. Contact angle measurements indicated that Epon 815 wets both fibers better than the corn oil. In addition, E-glass has lower contact angles with both fluids.