Optical Velocimetry Research Articles

Optical coherence tomography angiography-based capillary velocimetry.

Challenge persists in the field of optical coherence tomography (OCT) when it is required to quantify capillary blood flow within tissue beds in vivo. We propose a useful approach to statistically estimate the mean capillary flow velocity using a model-based statistical method of eigendecomposition (ED) analysis of the complex OCT signals obtained with the OCT angiography (OCTA) scanning protocol. ED-based analysis is achieved by the covariance matrix of the ensemble complex OCT signals, upon which the eigenvalues and eigenvectors that represent the subsets of the signal makeup are calculated. From this analysis, the signals due to moving particles can be isolated by employing an adaptive regression filter to remove the eigencomponents that represent static tissue signals. The mean frequency (MF) of moving particles can be estimated by the first lag-one autocorrelation of the corresponding eigenvectors. Three important parameters are introduced, including the blood flow signal power representing the presence of blood flow (i.e., OCTA signals), the MF indicating the mean velocity of blood flow, and the frequency bandwidth describing the temporal flow heterogeneity within a scanned tissue volume. The proposed approach is tested using scattering phantoms, in which microfluidic channels are used to simulate the functional capillary vessels that are perfused with the scattering intralipid solution. The results indicate a linear relationship between the MF and mean flow velocity. In vivo animal experiments are also conducted by imaging mouse brain with distal middle cerebral artery ligation to test the capability of the method to image the changes in capillary flows in response to an ischemic insult, demonstrating the practical usefulness of the proposed method for providing important quantifiable information about capillary tissue beds in the investigations of neurological conditions in vivo.

Flow of a yield-stress fluid over a cavity: Experimental study of the solid–fluid interface

This paper presents an experimental characterization of the flow of an elasto-viscoplastic fluid (Carbopol) over a dead zone constituted of the same material. The studied configuration consists of a closed rectangular channel with a cavity in its base. A curved solid–fluid interface forms into the cavity, separating a yielded flowing layer above from an unyielded dead zone below. The hydrodynamics of the flow is investigated by means of high-resolution optical velocimetry (PIV). We focus in particular on the velocity profiles and shear-rate evolution in a quasi-longitudinal flow domain located around cavity mid-length. Our measurements show a non-monotonous evolution of the shear rate, which increases from zero at the solid–liquid interface, passes through a peak (sometimes leveling off at its maximum value), and returns to zero in a plug zone sufficiently far above the cavity. Two main flow zones can be distinguished: a Poiseuille zone, in which velocity profiles are the same as in the flow over a rigid wall, and a boundary layer ensuring the transition with the dead zone. Hence, consistently with our previous work (Luu et al., 2015 [9]), the flow self-organizes to partially smooth out the bottom perturbation. The characteristic thicknesses of the flow zones are shown to evolve with cavity length and hydrodynamic properties of the incoming flow. The study also points out the influence of elastic effects, notably on the shape (asymmetry) of the solid–fluid interface.

Elastic turbulence in entangled semi-dilute DNA solutions measured with optical coherence tomography velocimetry

The flow instabilities of solutions of high molecular weight DNA in the entangled semi-dilute concentration regime were investigated using optical coherence tomography velocimetry, a technique that provides high spatial (probe volumes of 3.4 pL) and temporal resolution (sub μs) information on the flow behaviour of complex fluids in a rheometer. The velocity profiles of the opaque DNA solutions (high and low salt) were measured as a function of the distance across the gap of a parallel plate rheometer, and their evolution over time was measured. At lower DNA concentrations and low shear rates, the velocity fluctuations were well described by Gaussian functions and the velocity gradient was uniform across the rheometer gap, which is expected for Newtonian flows. As the DNA concentration and shear rate were increased there was a stable wall slip regime followed by an evolving wall slip regime, which is finally followed by the onset of elastic turbulence. Strain localization (shear banding) is observed on the boundaries of the flows at intermediate shear rates, but decreases in the high shear elastic turbulence regime, where bulk strain localization occurs. A dynamic phase diagram for non-linear flow was created to describe the different behaviours.

Fourier-based layout for grating function structure in spatial filtering velocimetry

Optical spatial filtering velocimetry (SFV) has been used for several decades for velocity measurements. Since the 1990s, charge-coupled device (CCD) line sensors have been used for the realization of spatial filtering systems by the inherent implementation of grating functions using a specialized clock regime. Another approach is the realization of optical SFV systems by utilizing array detectors (CCD or CMOS) with software-implemented grating functions, especially for two-dimensional velocity measurements.Choosing a suitable grating function for the observed scene can be an obstacle when using SFV, and relies on the experience of the user. With this in mind, this contribution presents an overview of how to assemble an optical spatial filtering system. After a general description of signal generation in spatial filtering systems, a straightforward approach to identifying matching harmonic grating functions by using Fourier analysis is presented. This approach has particular advantages for observed scenes with a periodically structured pattern, which were problematic when using SFV in connection with a fixed grating function. Matching periods of harmonic grating functions can be found as peaks in the spectral density distribution of the imaged scene. Once a matching grating function has been found, the signal processing can be made with SFV, which is simpler than calculating the cross-correlation of full frames and is suitable for real-time application. Criteria for the layout of an array-detector-based spatial filtering velocimeter are then discussed.

Combination of the optical analyzer technique and multiply photon doppler velocimetry to measure the sound velocities in shock-compressed metals

It is proposed to combine the optical analyzer technique (OAT) and multiply photon Doppler velocimetry (MPDV) in every explosive experiment in order to overcome the reported discrepancies in the sound velocities measured in shock-compressed metals using different techniques. Such a combination is demonstrated to be efficient in explosive experiments with stepped samples of 12Kh18N10Т austenitic stainless steel and high-purity Mg95 magnesium under their shock-wave loading in ranges of 60–120 and 20–30 GPa, respectively. The OAT ensures classical recording of the longitudinal and bulk sound velocities. Depending on the loading intensity, the MPDV technique recorded temporal changes in the velocity of the “sample–indicator” interface or temporal changes in the shock-front velocity in the indicator. These data were used to monitor the parameters of the shock-compressed sample and to determine the instant when the first characteristic of the rarefaction-wave fan overtakes the shock-wave front in the indicator. Within the range of relatively low loads where the indicating fluid remains transparent and acts as a window material, the MPDV registers temporal variations in the velocity of the “sample–indicator material” interface. The OAT ensures reliable registration in the range of high-intensity loads, while the MPDV ensures time-resolved registration of the steady-shock-wave front velocity in the indicator up to the instant of its overtaking by a rarefaction wave. Both techniques are observed to work well in the intermediate range of loads. Combining these techniques enhanced the reliability of the obtained consistent data on the sound velocities in shock-compressed structural materials and also allowed a decreased number of explosive experiments with samples of toxic materials.

Experimental progress of laser-driven flyers at the SG-III prototype laser facility

Laser-driven flyers have unique advantages of high flyer velocity, low cost, simple facility compared with the flyers driven by other conventional dynamic high-pressure loading techniques. With the fast development of laser technique, launching hypervelocity flyers with high-intensity laser pulse has become more and more prevalent. In this paper, we introduce the recent experiments of laser-driven flyers at the SG-III prototype laser facility. Three ways of launching hypervelocity flyers are developed and introduced, respectively. In the first way, multilayered aluminum flyers are gradually accelerated to a terminal velocity of 8 km/s, which is measured by optical velocimetry, without melting and vaporization. The pressure distribution within the flyer shows that the temporally ramped pulse ablation generates a compression wave, and the flyer is accelerated by this wave and its reverberation within the flyer. In the second way, a strong laser ablates the low-density reservoir foil and generates strong shock in the foil. The shock wave is strong enough, and when the shock breaks out from the free surface, the foil will unload as plasma towards the flyer with a density profile. The plasma decelerates upon colliding the flyer, and the single-layered flyer is gradually accelerated by the momentum transition. In our experiments, single-layered aluminum foil and single-layered tantalum foil are accelerated to 11.5 km/s and 6.5 km/s, respectively. According to the pressure distribution within the flyer, the flyer is also accelerated by the compression wave produced by the plasma collision, which is similar to the case of direct ablation by temporally ramped pulse. However, the way of plasma collision could better reduce X-ray and electron preheat and obtain cleaner flyers. In the last way, the flyers are launched by direct strong short-laser ablation. The multi-layered aluminum foil is accelerated to a high average velocity of 21.3 km/s by using a 3-ns quadrate laser pulse at 351 nm after spatial homogenization. A line-velocity interferometer system for any reflect (VISAR) is employed to monitor the processes of flyer launch and flight in a vacuum gap and the shock velocity associated with phase change in fused silica target after flyer impact is inferred. The reflectivity variations of the VISAR fringe pattern and the shock velocity in the fused silica suggest that the flyer owns a density gradient characteristic. Furthermore, specifically designed multi-layered flyers (polyimide/copper) are accelerated by shock impedance and reverberation techniques to a super high averaged velocity of 55 km/s, which is much faster than recently reported results. Light-emission signals of shock breakout and flyer impact on flat or stepped windows are obtained, which indicates the good planarity and integrity for the flyer. Compared with single-layer flyers, multi-layered flyers have a good planarity, and a high energy conversion efficiency from laser to flyers. In this paper, we give a comprehensive analysis and comparison of the experimental designs, technique means and data results about laser-driven flyers. This would provide a reference for further experimental study of laser-driven flyers and also verify that the SG-III prototype laser facility is a very promising facility for studying the hypervelocity flyers launching field.

Micro-bubbles seeding for flow characterization

Micro-bubbles injection has long been used in hydrodynamic facilities for the control of dissolved and free air. In some cavitation tunnels [9], very large quantities of microbubbles (billions per second) are injected for rapid degassing and, in smaller quantities (millions per second), for cavitation nuclei seeding. Micro-bubbles can also be used as tracers for optical measurements including visualization, LDV or PIV. For these applications, bubbles must be sufficiently small to faithfully follow the flow. Depending on the quality and spatial characteristics of the micro-bubbles seeding, several optical methods can be applied: simple visualization gives access to semi-quantitative information on the behaviour of flows; LASER velocimetry provides information on the mean velocity and other temporal local characteristics of the flow. This paper presents some new micro-bubbles seeding devices recently developed by YLEC Consultants. These devices have been designed to fulfill specific requirements related to integration into cavitation tunnels and permit optical velocimetry measurement techniques such as Particle Image Velocimetry (PIV).The LEGI cavitation tunnel is the first tunnel which has been equipped with these microbubbles seeding systems dedicated to optical velocimetry. This paper presents the final integration schemes selected for micro-bubbles seeding into LEGI tunnel and discuss about practical concerns related to the use of the injection system for optical velocimetry.

Fundamental uncertainty limit of optical flow velocimetry according to Heisenberg's uncertainty principle.

Optical flow velocity measurements are important for understanding the complex behavior of flows. Although a huge variety of methods exist, they are either based on a Doppler or a time-of-flight measurement principle. Doppler velocimetry evaluates the velocity-dependent frequency shift of light scattered at a moving particle, whereas time-of-flight velocimetry evaluates the traveled distance of a scattering particle per time interval. Regarding the aim of achieving a minimal measurement uncertainty, it is unclear if one principle allows to achieve lower uncertainties or if both principles can achieve equal uncertainties. For this reason, the natural, fundamental uncertainty limit according to Heisenberg's uncertainty principle is derived for Doppler and time-of-flight measurement principles, respectively. The obtained limits of the velocity uncertainty are qualitatively identical showing, e.g., a direct proportionality for the absolute value of the velocity to the power of 32 and an indirect proportionality to the square root of the scattered light power. Hence, both measurement principles have identical potentials regarding the fundamental uncertainty limit due to the quantum mechanical behavior of photons. This fundamental limit can be attained (at least asymptotically) in reality either with Doppler or time-of-flight methods, because the respective Cramér-Rao bounds for dominating photon shot noise, which is modeled as white Poissonian noise, are identical with the conclusions from Heisenberg's uncertainty principle.

Parametric study of the wetting transition of a moving meniscus

In this study, we investigated the wetting transition of a moving meniscus in a grooved microchannel through a detailed parametric study based on measurement by an optical tool and μ-particle image velocimetry (PIV) to avoid the transition in designing the microchannel. The parameters investigated were pitch, flow rate, and height of a microchannel. The contact angle, contact speed, and interfacial pressure difference were analyzed according to the parameters. We found that the pitch is most effective, the flow rate is moderately effective, and the height is least effective on that. The height even does not affect the contact angle, because the solid–fluid interaction at the groove edge is stronger than the fluid–air interaction. As the critical correlation, the contact angle, which is dependent on the pitch and the flow rate, and the height affect the air pressure between the grooves, which governs the air penetration flux and mainly determines the wetting transition. Therefore, a powerful way to delay the wetting transition is to reduce the degree of air pressure variation, specifically with a low pitch and a tall height with a low flow rate. Eventually, understanding dominant input parameters in relation to the wetting transition will be very useful in the design stage of microfluidic applications.

A technique for studying the response of materials to high rate, high strain deformation

A gas-gun technique is described in which a thick-walled cylinder of a chosen solid may be collapsed over a wide range of effective strains, and at shear strain-rates of the order 104 s−1. Two variants of the basic concept are described. Initially a 70 mm bore gun was used to dynamically collapse stainless steel 304 cylinders to a wide range of final effective strains. Early-stage shear bands were observed to intersect the inner circumference of the collapsed cylinder. However, although the configuration provides a useful vehicle for studying high rate, high strain deformation it has the disadvantage that the strain vs. time field experienced by the sample is complex. In addition, the 70 mm bore size limited the diameter of the specimen tube studied and hence diagnostic access to the collapsing cylinder wall was not possible. Therefore the Sandia hydrocode CTH was used to modify the initial configuration to generate a simpler strain history in the sample. This refinement of the original concept was used to implode cylinders of the titanium alloy Ti–6Al–4V using a larger 100 mm bore gas launcher. The velocities of the inner surfaces of the imploding cylinders were measured using optical velocimetry from which the macroscopic strain and shear strain-rate were determined as a function of time. The samples were sectioned after the tests, revealing severe localised adiabatic shear patterns. The gas-gun technique is shown to be a versatile configuration with potential for easily varying the specimen's initial geometry and the strain-rates at which it is collapsed.

In situ calibrated defocusing PTV for wall-bounded measurement volumes

In many situations, 3D velocity measurements in thin (∼1 mm) but wide (∼100 × 100 mm2) flow channels is an important task. To resolve the in-plane and out-of-plane velocity gradients properly, a precise calibration is required, since 3D measurement approaches rely strongly on the accuracy of the calibration procedure. It is likely that calibration targets do not fit domains with small depths, due to their size. Furthermore, in fields where such measurements are of interest, the accessibility of the measurement volume is often limited or even impossible. To overcome these drawbacks, this paper introduces an in situ calibrated defocusing particle tracking velocimetry approach for wall-bounded measurement domains with depths in the low millimeter range. The calibration function for the particle depth location is directly derived from the particle image geometries and their displacements between two frames. Employing only a single camera, this defocusing approach is capable of measuring the air flow between two parallel glass plates at a distance of 1 mm with an average uncertainty of 2.43% for each track, relative to the maximum velocity. A tomographic particle tracking velocimetry measurement, serving as a benchmark for the single camera technique, reaches an average uncertainty of 1.59%. Altogether, with its straightforward set-up and without requiring a calibration target, this in situ calibrated defocusing approach opens new areas of application for optical flow velocimetry. In particular, for measurement domains with small optical windows and a lack of accessibility.

Spatial filtering velocimetry for real-time measurements of speckle dynamics due to out-of-plane motion.

This paper describes an optical spatial filtering velocimetry technique that converts an expanding or contracting speckle pattern into a photocurrent. This photocurrent will have a quasi-sinusoidal dependency on this specific speckle motion. The spatial filter consists of a series of concentric rings. Each ring divides the incoming light into two radial-wise, almost even contributions and directs them by refraction toward two half-rings of photodetectors. The corresponding two photocurrents are balanced and provide a differential photocurrent. In this paper the optical spatial filtering velocimetry technique is used to demonstrate real-time measurements of speckle dynamics due to out-of-plane motion.

Non-intrusive calibration for three-dimensional particle imaging

This letter introduces a non-intrusive calibration scheme for three-dimensional (3D) optical flow velocimetry techniques. For these 3D techniques, including tomographic PIV and 3D-PTV, calibration targets need to be imaged within the measurement volume at different depth positions. However, for domains with limited access and with small dimensions, it is difficult or impossible to place a calibration target. Therefore, a non-intrusive calibration approach is proposed to overcome these drawbacks, by employing light reflections of a continuous wave laser in the measurement domain. The laser is translated to different locations, yielding a set of calibration points, comprising the spatial coordinates of the light reflections and their corresponding sensor coordinates.

Stereoscopic Particle Image Velocimetry Investigation of the Bidirectional Natural Convection Flow Through a Horizontal Vent

An experimental study investigates the natural convection flow through a horizontal ceiling vent of a fire compartment. This flow is governed by the buoyancy forces and the friction forces, and is bidirectional. The orifice used is of circular cross section and is characterized by the aspect ratio L/D of its thickness L over its diameter D. The reduced scale apparatus consist of two superimposed compartments of $$1.5 \times 1 \times 1 \, \mathrm{m}^3$$ for the lower and $$1 \times 1 \times 1 \, \mathrm{m}^3$$ for the upper. These two rooms are connected by a 0.038 m length circular orifice with different diameters available ( $$ D \in [63.5, \, 76.2, \, 127, \, 152.4, \, 190.5, \, 260$$ mm]). For the study of natural convection, only the lower compartment is used; the upper compartment is left at atmospheric conditions by removing all its walls. The temperature gradient ( $$\Delta T \approx 50^\circ $$ C between the bottom and the top of the orifice) is generated by a 2 kW electrical resistor located in the lower compartment. This electrical resistor makes it possible to generate, without mass inlet, a plume with no soot and to reach a thermal steady state in the “fire room”. The optical stereoscopic particle image velocimetry measurement technique provides the velocity field through the opening for different diameters. This technique, based on the finding of the displacement of a set of particles between two consecutive snapshots of a seeded fluid, makes it possible to obtain all three components of the velocity vector field by non-intrusive measurement. The use of this technique is a novelty for such vent flows and allows accessing information not only on the variation of the flow rate but also on the distribution of the fluids moving upward and downward through the orifice. Despite an unsteady dynamic regime, the analysis of averaged fields shows a geometrical organization of the bidirectional flow through the orifice, with a central area occupied by the hot fluid flowing upward and a peripheral zone where the cold fluid flows downward. The flow section occupancy ratio reverses with the extrema of flow velocities, for $$L/D \approx 0.41$$ .

Formation of vortices in long microcavities at low Reynolds number

Microcavities are a central feature of many microflow systems ranging from sprouting capillaries during angiogenesis to various microfluidic devices. Recently, the flow and transport phenomena in microcavities have been subject of a number of studies, yet a physical picture of the flow properties at low Reynolds number, which is the relevant regime in many biological applications, has not been fully brought out. We have therefore systematically investigated, experimentally and by modeling, the flow in a long microcavity and found that the flow properties depend decisively on the depth/width ratio of the cavity. Notably, if this cavity aspect ratio is higher than approximately 0.51, counter-flow vortices emerge in the cavity even at vanishing Reynolds number. The distance of the first vortex from the cavity entrance decreases with an increasing aspect ratio as an inverse power law. In the vortex-free regime below the threshold aspect ratio, the flow velocity decays exponentially away from the cavity entrance, with a decay length that scales with the width of the cavity and depends also on the aspect ratio of its cross section. The results of our numerical simulations are supported by a theoretical analysis and are in good agreement with experimental data, acquired by optical velocimetry with optical tweezers.

Hypervelocity launching of flyers at the SG-III prototype laser facility

Experiments of laser-driven hypervelocity flyers have been conducted at the SG-III prototype laser facility. Using the continuum phase plate technique, four laser beams each with a 3-ns quadratic profile are configured to produce relatively uniform irradiated spots of diameter size either 500 μm or 2000 μm. With the former, specifically designed multi-layered flyers (polyimide/copper) were accelerated by shock impedance and reverberation techniques via direct laser ablation to a super-high averaged velocity of 55 km/s, much faster than recently reported results. Light-emission signals of shock breakout and flyer impact on flat or stepped windows were obtained that indicated good planarity and integrity for the flyer. In the latter, single-layered aluminum flyers were gradually accelerated to a terminal velocity of 11 km/s, as measured by optical velocimetry, without melting and vaporization. The results suggest that the SG-III prototype laser facility has the capability to launch high-speed flyers to create extreme conditions for investigating the science of shock compression and its equation of state.

On the visualization of droplet deformation and breakup during high-pressure homogenization

The properties of emulsions are strongly influenced by the size distribution of the droplets. In order to achieve droplets on a microscale, high-pressure homogenization is used to transfer stresses to the droplet surface in the flow field upstream, in and downstream the disruption unit of the homogenizer. The droplets are deformed and eventually break up when exceeding critical values. Inline measurement techniques are still very challenging, due to highly complex flow conditions on microscales, high process pressures and large velocities. In this work, the optical flow measurement technique micro particle image velocimetry (μPIV) is used to quantify the flow field, the local stresses as well as droplet deformation and breakup. A special homogenization orifice which is optical accessible enabled the visualization in the whole area of interest before, in and after the restriction up to 80 bars homogenization pressure. The study of the single-phase flow with particular focus on the local stresses showed laminar and transitional conditions at Re number ranging from 285 to 1280. Droplets of two different viscosities are then examined at these conditions while passing the orifice. At the inlet, their size, deformation and position are investigated by an automated image processing algorithm and correlated with the local velocity gradients. At the outlet and downstream, deformation and breakup of droplets are shown within the possibilities of the μPIV and discussed in relation to known droplet breakup mechanisms. Finally, the droplet size distributions offline obtained by static light scattering are compared with observed phenomena of the individual drops in order to gain insights into droplet disruption in high-pressure homogenization.

Startup shear of a highly entangled polystyrene solution deep into the nonlinear viscoelastic regime

We have employed optical particle tracking velocimetry to directly visualize the deformation field of a highly entangled polystyrene/diethyl phthalate (PS/DEP) solution (entanglement density Z = 61) in a parallel plate geometry. To probe the existence of shear banding, startup shear tests were carried out deep into the nonlinear viscoelastic (NLVE) regime. By roughening the surface of the rheometer plates, wall slip was effectively suppressed. In the presence of edge fracture and prior to it, steady-state shear banding was not seen as evidenced by velocity profiles that were linear for most of the shear tests. An exception was for an extremely high Weissenberg number Wi = 255, for which weak transient banding was observed. For the PS/DEP system studied, the results suggest that in the absence of wall slip, shear banding is not a steady-state phenomenon and weak shear banding is observed only in the transient state and this could possibly correlate with the edge fracture effects.

Zonal jets in equilibrating baroclinic instability on the polar beta‐plane: Experiments with altimetry

AbstractResults from the laboratory experiments on the evolution of baroclinically unstable flows generated in a rotating tank with topographic β‐effect are presented. We study zonal jets of alternating direction which occur in these flows. The primary system we model includes lighter fluid in the South and heavier fluid in the North with resulting slow meridional circulation and fast mean zonal motion. In a two‐layer system, the velocity shear between the layers results in baroclinic instability which equilibrates with time and, due to interaction with β‐effect generates zonal jets. This system is archetypal for various geophysical systems including the general circulation and jet streams in the Earth's atmosphere, the Antarctic Circumpolar Current, or the areas in the vicinity of western boundary currents where baroclinic instability and multiple zonal jets are observed. The gradient of the surface elevation and the thickness of the upper layer are measured in the experiments using the Altimetric Imaging Velocimetry and the Optical Thickness Velocimetry techniques, respectively. Barotropic and baroclinic velocity fields are then derived from the measured quantities. The results demonstrate that the zonal jets are driven by “eddy forcing” due to continuously created baroclinic perturbations. The flow is baroclinic to a significant degree and the jets are “surface intensified.” The meridional wavelength of the jets varies linearly with the baroclinic radius of deformation and is also in a good agreement with a modified Rhines scale. This suggests a linear dependence of the perturbation velocity in the equilibrated baroclinically unstable flow on the β‐parameter.

Experimental evaluation of a facility for jet induced flow analysis

In this work, the performance of a bench, which was designed for investigating the hydrodynamics of jets and plumes in quiescent environment is evaluated. This bench is mainly composed by a water tank with a nozzle placed at the center of its bottom. Through the nozzle, fluid is injected vertically upward into the tank. The tank, with square cross section, has a device attached to its upper edge for containing overflow. For fluid flow measurement and visualization, the optical technique Stereo Particle Image Velocimetry (SPIV) was employed and the influence parameters for the resulting flow pattern inside the tank were analyzed. The investigations showed that, in order to avoid tank wall effects to the axisymmetric jet profile, the minimum and maximum flow rate of injected liquid allowed in the stagnant environment were 0.05 L/min and 0.20 L/min, respectively. All the measurements were accomplished under the maximum water column in the tank.