Droplet Radius Research Articles

Characterization of Voltage Generation Obtained from Water Droplets on a Taro Leaf (Colocasia esculenta L) Surface

Voltage generation was obtained using a water droplet characterization on a taro (Colocasia esculenta L) leaf surface. This method relies on the superhydrophobic effect from the contact angle between the water droplet and the taro leaf’s surface allowing electron jumping and voltage generation. Water droplets were dropped on the top of taro leaf surface equipped with aluminum foil underneath as an electrode. The voltage was measured at various slope angles of 20°, 40° and 60° in a real-time basis. A digital camera was used to capture the droplet movement and characterization. It is found that the taro leaf has a surface morphology of nano-sized pointed pillars which created a superhydrophobic field. The energy generation was primarily obtained from the electron jump which was caused by the surface tension of the nano-stalagmite structure assisted by the minerals contained in the taro leaf surface. The results reported that the smaller the droplet radius (the smaller the droplet surface area), the greater the droplet surface tension and the greater the voltage generation. Furthermore, the highest voltage generation was obtained 321.2 mV at 20°-degree angle of slopes.

New insights into protein stabilized emulsions captured via neutron and X-ray scattering: An approach with β-lactoglobulin at triacylglyceride-oil/water interfaces

HypothesisTo analyze protein stabilized emulsions, SAXS and SANS are emerging techniques capturing oil droplet radius, interfacial coverage and structure. Protein shape, thus protein structure change during interfacial adsorption with partial protein unfolding is detected via SAXS analysis at and below the monolayer concentration for proteins, known as critical interfacial concentration (CIC). SANS determines the same phenomena below and above the CIC, via contrast variation and coarse-grained modelling. Experimentsβ-lactoglobulin concentration dependent SAXS experiments were performed focusing on molecular length scales to characterize protein shape in water, and interfacial structure in emulsions. Complementary SANS experiments with contrast variation via deuterated triacylglyceride-oil provided insight into oil droplet radius, interfacial coverage and structure via data analysis with scattering models and low-resolution shape reconstruction with the DENFERT model. FindingsSAXS and SANS experiments allowed to determine the interfacial structure below and above the CIC, as well as oil droplet radius and interfacial coverage. These findings were identified via Q-4 Porod scattering at low-Q, protein scattering at high Q, and a Q-2 scattering of the interface. Since SANS with accurate contrast variation highlights the interface in comparison to other techniques like FTIR, the presented results show a high impact to understand interfaces in emulsions.

Improved Heat Transfer Modeling of Moist Air Condensation on Hydrophobic Metallic Surface

For dropwise condensation of water over a textured surface, the condensation rate is limited by the conduction resistance of the droplet. Conduction models with varying levels of approximation have been reported in the literature. In the present study, the conduction resistance of a spherical-cap droplet is derived by regression analysis of data generated by 3D numerical simulation. Results show that conduction resistance is sensitive to the choice of contact angle and droplet radius. The proposed model has significant differences from reported models which are based on 1-D and 2-D approximations. An important source of discrepancy is traced to additional heat flux localized at the three-phase contact line. Equivalently, high local heat flux serves to lower thermal resistance between the vapor-liquid interface and the condensing wall. The prediction of the droplet growth rate using the proposed conduction model is in good agreement with the experiments reported in the literature. The improved conduction resistance correlation is incorporated in the model for a space- and time-resolved dropwise condensation cycle for vapor condensing from moist air. Simulations with the improved condensation model show close agreement with experimental data, justifying the utility of an improved correlation for conduction resistance.

Fingerprinting pattern of orange essential oils in surfactant-free microemulsion by 3D fluorescence spectroscopy

The effect caused by surfactant-free microemulsion (SFME) systems in orange essential oil analysis was evaluated by 3D fluorescence spectroscopy. The SFME formation region was studied at different water:EO proportions (1:4, 1:2, 1:1, 2:1, 4:1 w/w) in the presence of propanol and octanol (10:3 w/w). Conductometric titrations indicated micellar aggregates containing EO (oil-in-water microemulsion) for the 4:1 proportion (droplets of hydrodynamic radius of 95.7 ± 5.3 nm). In such conditions, fluorescence increased allowing the use of 3D fluorescence spectroscopy to obtain spectroscopic fingerprint pattern that was used aiming discriminant analysis, considering nine EO Brazilian brands, along with unfold principal component analysis (UPCA). Cumulative variance of 96.7 % was obtained for the first three principal components and score plots showed distinct location for each group. Preliminary study showed the capability of these systems in evaluating storage conditions, and adulteration. The impact of storage conditions was made over 21 days exposed to light with results showing large spectral differences compared to a sample stored in amber flask at 22 °C. Adulteration of EOs by canola and mineral oil fortification was detected at different levels (1, 5, 10 and 20 %, in mass proportion) and, in addition to the spectral differences, a change in microemulsion stability was observed.

Three-dimensional Euler grid approximation method for multi-droplet motions in the steam-water separator

Motions of multi-droplets in steam flow are a common and important phenomenon in various fields such as the environment, chemical industry, and energy. To simulate the motion of multiple droplets, a three-dimensional Euler grid approximation method, which applies to structured and unstructured grids, was proposed. Criteria were established to ensure that the motion of droplets is restricted to the grid nodes without compromising accuracy. The method is capable of updating the information of multiple droplets at each calculation step for all nodes and obtaining distribution information including droplet density and velocity. The multi-droplet motions in the steam separator were simulated and velocity field of multi-droplets showed a symmetrical distribution. The multi-droplet motions process in the swirl vane separator of the steam-water separator was also simulated. The results demonstrated that under the studied operating conditions, the critical droplet radius that can be separated by the steam-water separator was 40 μm. The specific positions of droplet-wall collisions were mainly concentrated on the blades and outer wall of the swirl-vane separator, as well as the inner cylinder. The model may serve as a dependable guide for the optimal solution of separation device structures and simulating various other multi-droplet motion processes.

A Closer Look at the Evolution of Supercooled Cloud Droplet Temperature and Lifetime in Different Environmental Conditions with Implications for Ice Nucleation in the Evaporating Regions of Clouds

Abstract This study investigates the evolution of temperature and lifetime of evaporating, supercooled cloud droplets considering initial droplet radius (r0) and temperature (), and environmental relative humidity (RH), temperature (T∞), and pressure (P). The time (tss) required by droplets to reach a lower steady-state temperature (Tss) after sudden introduction into a new subsaturated environment, the magnitude of ΔT = T∞ − Tss, and droplet survival time (tst) at Tss are calculated. The temperature difference (ΔT) is found to increase with T∞, and decrease with RH and P. ΔT was typically 1–5 K lower than T∞, with highest values (∼10.3 K) for very low RH, low P, and T∞ closer to 0°C. Results show that tss is <0.5 s over the range of initial droplet and environmental conditions considered. Larger droplets (r0 = 30–50 μm) can survive at Tss for about 5 s to over 10 min, depending on the subsaturation of the environment. For higher RH and larger droplets, droplet lifetimes can increase by more than 100 s compared to those with droplet cooling ignored. Tss of the evaporating droplets can be approximated by the environmental thermodynamic wet-bulb temperature. Radiation was found to play a minor role in influencing droplet temperatures, except for larger droplets in environments close to saturation. The implications for ice nucleation in cloud-top generating cells and near cloud edges are discussed. Using Tss instead of T∞ in widely used parameterization schemes could lead to enhanced number concentrations of activated ice-nucleating particles (INPs), by a typical factor of 2–30, with the greatest increases (≥100) coincident with low RH, low P, and T∞ closer to 0°C. Significance Statement Cloud droplet temperature plays an important role in fundamental cloud processes like droplet growth and decay, activation of ice-nucleating particles, and determination of radiative parameters like refractive indices of water droplets. Near cloud boundaries such as cloud tops, dry air mixes with cloudy air exposing droplets to environments with low relative humidities. This study examines how the temperature of a cloud droplet that is supercooled (i.e., has an initial temperature < 0°C) evolves in these subsaturated environments. Results show that when supercooled cloud droplets evaporate near cloud boundaries, their temperatures can be several degrees Celsius lower than the surrounding drier environment. The implications of this additional cooling of droplets near cloud edges on ice particle formation are discussed.

In situ study on the oscillation of mobile droplets and force analysis during the directional solidification of Al-Bi alloy

During solidifications of immiscible alloys, the motion of droplets at the solid/liquid (S/L) interface is generally driven by dragging force, gravity force, repulsion force of interface, and thermal-solutal Marangoni force. However, there is few in situ study investigating kinetics behavior to analyze the forces on droplets. The mechanism of droplet motion remains unclear due to the unavailability or uncertainty of the effect of convection and solutal Marangoni force on droplet behavior. In this study, directional solidification of immiscible Al-Bi alloy was observed via synchrotron radiography, and the horizontal oscillation of droplets at S/L interface was detected for the first time. Forces, especially solutal Marangoni force, were calculated based on the in situ measured radius of droplets and thermal-solutal gradients. The experimental results cannot be reasonably explained by the previous analysis model which neglects melt convection. The non-negligible effect of flow on droplet motion was demonstrated, and the force balance of droplet both vertically and horizontally can be obtained considering a lift force of 6.39 × 10−9 N and a modified solute-related parameter dσdc of 0.45−0.65 J m−2, respectively.

Simulation of morphology for oil droplets in aqueous solution controlled by electric fields

This study investigate the morphology of oil-in-water at high density ratio controlled by electric field. We incorporated the electric field into the Lattice Boltzmann method (LBM). The focus is on the modified lattice Boltzmann color gradient model simulate the evolution of the oil-in-water and analyze the relation between morphologies and electric field parameters. The results show that the stretching, merging and even breaking can be regulated by electric field strength, conductivity, dielectric constant, oil-water density ratio and droplet radius. Simulation results showed that the larger dielectric constant resulted in the smaller deformation, and the larger conductivity related to the greater deformation. Meanwhile, the larger radius droplet is easier to deform and break, and the higher density droplet is less likely to break. And this paper also gives the morphology of the stretching and destabilization of the droplets at each stage. These results are in good agreement with the relevant theoretical and experimental results.

Reducing the condensing flow effects on the steam turbine blades through modified design geometry

Nowadays, a large part of energy is provided by steam turbines; thus, increasing the efficiency and improving the steam turbines performance are of special importance. The presence of the liquid phase in the low-pressure stage of the steam turbine can cause energy loss, efficiency drop, and erosion/corrosion problems; therefore, one of the essential issues is to identify wet steam flow and try to reduce condensation loss. In order to decrease the liquid fraction, the drainage groove technique can be applied. The drainage groove sucks the water droplets from the turbine blade surface and drains them into the condenser. In this study, the effect of the drainage groove location on the surface of steam turbine blades has been investigated on the condensation, droplet radius, inlet mass flow, erosion rate, liquid drainage ratio, condensation losses, and total drainage ratio. For modeling the condensing flow, the Eulerian–Eulerian approach has been applied. The results show that the location of the drainage groove affects the groove performance and flow pattern in the turbine blade. In the selected drainage, the liquid drainage ratio, condensation losses, and erosion rate are reduced by 7.6%, 12%, and 88%, respectively, compared with the no-drainage groove case. Also, the total drainage ratio is 7.2% in the selected drainage. The outcomes of the present work have been a major step forward in the techniques having a great influence on the lifetime, repair and maintenance, and the output power of steam power generation facilities.

Experimental and numerical analysis of the emulsification of oil droplets in water with high frequency focused ultrasound

Focused high frequency ultrasound emulsification provides significant benefits such as enhanced stability, finer droplets, elevated focal pressure, lowered power usage, minimal surfactant usage and improved dispersion. Hence, in this study, the high frequency focused ultrasound emulsification of oil droplets in water was investigated through experiments and numerical modeling. The effect of transducer power (74–400 W), frequency (1.1 and 3.3 MHz), oil viscosity (10.6–512 mPas), interfacial tension (25–250 mN/m) and initial droplet radius (10–750 µm) on the emulsification process was assessed. In addition, the mechanism of droplet break-up was examined. The experiments showed that the acoustic pressure increased from 9.01 MPa to 26.24 MPa as the power was raised from 74 W to 400 W. At 74 W, the Weber number (We) at the surface and focal zone are 0.5 and 939.8, respectively. However, at 400 W, the We at the transducer surface and focal region reached 2.7 and 6451.8, respectively. Thus, bulb-like and weak catastrophic break up dominates the emulsification at 74 W. The catastrophic break up at 400 W is more vigorous because the ultrasound disruptive stress and We are higher. The time for the catastrophic dispersion of a single droplet at We = 939.8 and We = 6451.8 are 1.01 ms and 0.45 ms, respectively. The numerical model gives reasonable prediction of the trend and magnitude of the experimental acoustic pressure data. The surface and focal pressure amplitudes were estimated with errors of ∼ 6.5% and ∼ 10%, respectively. The predicted Reynolds number (Re) between 74 and 400 W were 8442 and 21364, respectively. The acoustic pressure at the focal region were ∼ 26 MPa and ∼ 69 MPa at frequencies of 1.1 MHz and 3.3 MHz, respectively. Moreover, the acoustic velocities were ∼ 16 m/s and ∼ 42 m/s at 1.1 MHz and 3.3 MHz, respectively. Hence, smaller droplets could be attained at higher frequency excitation under intense catastrophic modes. The Ohnesorge number (Oh) increased from 0.062 to 3.12 with the viscosity between 10.6 mPas and 530 mPas. However, the We remained constant at 856.14 for the studied range. Generally, higher critical We is required for the different breakup stages as the viscosity ratio is elevated. Moreover, the We increased from 25.68 to 1284.22 as the droplet radius was elevated from 15 to 750 µm. Larger droplets allow for higher possibility and intensity of breakup due to diminished viscous and interfacial resistance.

Magnetic-field-driven director configuration transitions in radial nematic liquid crystal droplets.

We study the director configurations of nematic liquid crystal (NLC) droplets with homeotropic anchoring in a magnetic field and report observation of a magnetic-field-driven transition from a deformed radial to an axial-with-defect configuration. Magnetic-field-induced transitions in NLC droplets differ fundamentally from the traditional planar Freedericksz transition due to the spherical droplet geometry and resulting topological defect. This transition has been studied theoretically, but the director configurations and mechanism of defect evolution in an applied magnetic field have yet to be observed experimentally. To this end, we combine polarized optical microscopy with a variable electromagnet (≤1T) for continuous observation of droplet director fields, and we employ Landau-de Gennes numerical simulations to elucidate the director configurations and first-order nature of the transition. We report a configuration transition from point defect to ring defect at a critical field, which varies inversely with droplet radius and is relatively independent of surfactant type and concentration. We also estimate anchoring strengths of commonly used surfactants at the NLC-aqueous interface.

Thermocapillary migration of a compound droplet on a substrate

We present a numerical study of the thermal migration of a compound droplet attached to a horizontal substrate. The different constant temperatures are applied to the left and right boundaries of the computational domain. The compound droplet contains one inner core. The problem is solved by using a front-tracking technique associated with the finite difference method. The investigated parameters include the radius ratio (Rio) of the inner droplet and the equivalent radius of the outer droplet (Rio varied in the range of 0.2 to 0.7), the viscosity ratio (μom) of the outer to middle fluids (μom varied in the range of 0.1 to 2.4), and the static contact angle θe (θe varied in the range of 60° to 120°). The results reveal that the inner droplet drives the compound droplet towards the hot region as its radius is sufficiently large (Rio≥ 0.6). The compound droplet moves towards the cold region as the value of Rio is less than 0.6. Increasing the viscosity of the outer fluid (by increasing μom) or θe causes the compound droplet to move towards the hot region. The trajectory of the centroid of the inner droplet is also investigated.

Angular Patterns of Nonlinear Emission in Dye Water Droplets Stimulated by a Femtosecond Laser Pulse for LiDAR Applications

Femtosecond laser-induced fluorescence (FLIF) and femtosecond laser-induced optical breakdown spectroscopy (FIBS) are important tools for remote diagnostics of atmospheric aerosols using LiDAR (Light Identification Detection and Ranging) technology. They are based on light emission excitation in disperse media via multiphoton nonlinear processes in aerosol particles induced by high-power optical pulses. To date, the main challenge restraining the large-scale application of FLIF and FIBS in atmospheric studies is the lack of a valued theory of the stimulated light emission in liquid microparticles with a sufficiently broad range of sizes. In this paper, we fill this gap and present a theoretical model of dye water droplet emission under high intensity laser exposure that adequately simulates the processes of multiphoton excited fluorescence and optical breakdown plasma emission in microparticles and gives quantitative estimates of the angular and power characteristics of nonlinear emission. The model is based on the numerical solution to the inhomogeneous Helmholtz equations for stimulating (primary) and nonlinear (secondary) waves provided by the random nature of molecule emission in particles. We show that droplet fluorescence stimulated by multiphoton absorption generally becomes more intense with increasing particle size. Moreover, far-field plasma emission from liquid particles demonstrates a larger angular diversity when changing the droplet radius in comparison with multiphoton excited fluorescence, which is mainly due to the excitation of the internal optical field resonances in spherical particles.

On the stability of a charged rotating liquid droplet in plasma

The instability condition of a charged liquid dust particle (droplet) immersed in a plasma is considered theoretically. Both charging process and rotation effect are incorporated in the model. The dependence of the critical charge on the droplet radius is obtained for the regimes of fast and slow fragmentation.

Coalescence-induced droplet jumping on superhydrophobic surfaces with non-uniformly distributed micropillars

The phenomenon of droplet jumping induced by coalescence holds significant potential for application in diverse areas such as water collection, self-cleaning, and thermal management of electronic devices. In comparison to a flat surface, a superhydrophobic surface with structure can affect the interaction between the droplet and the surface, thereby affecting parameters such as the droplet jumping velocity. In this study, numerical simulation was used to examine the similarities and differences of coalescence-induced droplet jumping on superhydrophobic surfaces with uniform and non-uniform micropillars, as well as the effect of micropillar non-uniformity on droplet jumping. The results indicated that the non-uniform distribution of micropillars could lead to asymmetries in the shrinkage of the liquid bridge, the morphology of the droplet when it jumps off the surface, and the distribution of the high-pressure region at the bottom of the droplet. Additionally, it decreased the droplet’s vertical velocity while substantially increasing the horizontal velocity. When the droplet radius was constant, decreasing the micropillar width or increasing the micropillar spacing on the sparse side was advantageous for the droplet jumping on a superhydrophobic surface with non-uniform micropillars. By defining the solid fraction on the micropillar surface with non-uniform distribution, the coupling effect of the width and spacing of the micropillars on the droplet jumping was thoroughly analyzed, and the optimal solid fraction for the best directional transport effect of droplets was determined. This study revealed the mechanism underlying the effect of surface micropillar structure on coalescence-induced droplet jumping, and the findings could guide the design of superhydrophobic surface microstructures, which was of great significance for the advancement of droplet jumping applications.

Mathematical model of killing an oil horizontal well

The physical picture of the killing fluid and the formation fluid movement in the process of killing a horizontal oil well has been described, a physical and mathematical model of the process has been developed and the limits of the model applicability have been indicated. It is recommended to conduct the killing process in two stages, separated by a technological break. During the first stage, the injected killing fluid fills the tubing, the annulus and the part of the horizontal wellbore. For the duration of the technological break, the denser tubing slowly displaces the formation fluid from the horizontal wellbore into the annulus where the formation fluid floats to the surface in the form of droplets. For the period of the second stage, the remaining amount of tubing is pumped into the well. The model is based on the well-known hydraulic equations for laminar flow of liquids, the solution of the flooded jet problem, as well as the model of one-dimensional vertical inertialess flow of a two-phase medium with incompressible phases. A closed system of equations has been formed taking into account the viscous friction losses on the walls of the horizontal pipe and at the interface between the formation fluid and the killing fluid flows. The solution of this system has been obtained and the values of the main process parameters have been found: velocities and flows of liquid gas and liquid coolant and time of complete replacement of liquid coolant by the killing fluid depending on the inclination angle of the horizontal pipe. It is shown that the character of the movement of the formation fluid drops in the pipe space depends on their volume fraction φ in the mixture with the killing fluid. With the value φ < 1/3 the jelly drops float up with a constant speed, while the jelly droplet radius and the speed of their floating up are unambiguously determined by the jelly stream size, density and viscosity of jelly and liquid hydrocarbon. The graphs of dependence of these parameters on the value of the formation fluid flow have been presented. On the basis of the research the recommendations for the process of killing horizontal oil wells have been formulated.

Robust interpolation for dispersed gas‐droplet flows using statistical learning with the fully Lagrangian approach

SummaryA novel methodology is presented for reconstructing the Eulerian number density field of dispersed gas‐droplet flows modelled using the fully Lagrangian approach (FLA). In this work, the nonparametric framework of kernel regression is used to accumulate the FLA number density contributions of individual droplets in accordance with the spatial structure of the dispersed phase. The high variation which is observed in the droplet number density field for unsteady flows is accounted for by using the Eulerian‐Lagrangian transformation tensor, which is central to the FLA, to specify the size and shape of the kernel associated with each droplet. This procedure enables a high level of structural detail to be retained, and it is demonstrated that far fewer droplets have to be tracked in order to reconstruct a faithful Eulerian representation of the dispersed phase. Furthermore, the kernel regression procedure is easily extended to higher dimensions, and inclusion of the droplet radius within the phase space description using the generalised fully Lagrangian approach (gFLA) additionally enables statistics of the droplet size distribution to be determined for polydisperse flows. The developed methodology is applied to a range of one‐dimensional and two‐dimensional steady‐state and transient flows, for both monodisperse and polydisperse droplets, and it is shown that kernel regression performs well across this variety of cases. A comparison is made against conventional direct trajectory methods to determine the saving in computational expense which can be gained, and it is found that times fewer droplet realisations are needed to reconstruct a qualitatively similar representation of the number density field.

Interfacial activity dynamics of confined active droplets

Active emulsions can spontaneously form self-propelled droplets or phoretic micropumps. However, it remains unclear how these active systems interact with their self-generated chemical fields, which can lead to emergent chemodynamic phenomena and multistable interfacial flows. Here, we simultaneously measure the flow and chemical concentration fields using dual-channel fluorescence microscopy for active micropumps, i.e. immobilised oil droplets that dynamically solubilise in a supramicellar aqueous surfactant solution. With increasing droplet radius, we observe (i) a migration of vortices from the posterior to the anterior, analogous to a transition from pusher- to puller-type swimmers, (ii) a bistability between dipolar and quadrupolar flows and, eventually, (iii) a transition to multipolar modes. We also investigate the long-time dynamics. Together, our observations suggest that a local build-up of chemical products leads to a saturation of the surface, which controls the propulsion mechanism. These multistable dynamics can be explained by the competing time scales of slow micellar diffusion governing the chemical buildup and faster molecular diffusion powering the underlying transport mechanism. Our results are directly relevant to phoretic micropumps, but also shed light on the interfacial activity dynamics of self-propelled droplets and other active emulsion systems.

Heat flux characteristics of a single droplet splashing on the liquid film obtained with a thermal lattice Boltzmann method

The double-distribution-function thermal lattice Boltzmann method is employed to investigate the heat flux characteristics of single droplet impact on a liquid film above a heated wall. The effects of impact velocity, liquid film thickness, droplet radius, and viscosity coefficient on the average and instant heat flux distribution are analyzed. The droplet impact first breaks the steady-state thermal boundary layer in the impact region, causing the heat flux in the wall impact region to increase. This is because the temperature gradient between the liquid film and the wall increases as the droplet dives downward and expands. The velocity discontinuity at the liquid jet sheet prevents the transfer of the transverse velocity in the liquid film to the static region, yielding a transition region. Convective heat transfer is dominant in the impact and transition regions, while conductive heat transfer is dominant in the static region. Moreover, a large impact velocity promotes the synergy between the temperature and flow velocity fields, enhancing the heat transfer efficiency. The kinetic energy consumption of the droplet increases with the liquid film thickness, which causes the heat flux to decrease. The effect of droplet radius on the heat flux at the wall is minimal. Furthermore, an increased liquid viscosity is not beneficial for wall heat dissipation.

Droplet heating and evaporation: A new approach to the modeling of the processes

A new model for mono-component droplet heating/evaporation is developed, tested, and applied to the analysis of in-house experimental data. The new model links the previously developed liquid phase model, using the analytical solution to the heat transfer equation at each time step, and the gas phase model, using the solution to the equations of the conservation of mass, momentum, and energy leading to an explicit expression for the Nusselt number and implicit expression for evaporation rate of the droplet. The latter expressions are used as boundary conditions for the liquid phase model. The new model is verified using a comparison between its predictions of the droplet temperatures and radii for very large liquid thermal conductivity [1000 W/(m K)] and those of the model, using the assumption that the thermal conductivity of liquid is infinitely large. The closeness between the predictions of these models supports the reliability of both. The model is validated using the experimental data obtained at the Heat and Mass Transfer laboratory of Tomsk Polytechnical University with regard to the heating/evaporation of droplets. The deviations between the measured and predicted droplet radii and temperatures in most cases are shown to be within experimental error margins.