Vertical Loop Research Articles

Implementation of a ultraviolet area imaging detector for analysis of polyvinyl alcohol microbubbles by capillary electrophoresis

Contrast agents are widely used to enhance the image quality in clinical imaging using e.g. ultrasound. The contrast agents used for ultrasound imaging are mainly microbubbles (MBs) with a soft or hard shell encapsulating a core of gas. In the present study, MBs with a hard shell of polyvinyl alcohol (PVA), and a core of air were analysed in a capillary electrophoretic system using a UV area imaging detector. The detector was operating at 3 wavelengths; 214 nm, 255 nm and 525 nm, and the highest absorbance for individual PVA-MBs were obtained at 214 nm. Two detection windows and a vertical loop capillary position enabled tracking of the PVA-MBs both in an upward and a downward flow direction, where PVA-MBs had different flow distributions and slightly higher average flow velocity upwards, attributed to temperature differences in the capillary that was part within the instrument and part outside. The tracking also allowed counting and quantification of the PVA-MBs. Separation of PVA-MBs from proteins present in human blood plasma was achieved, with multi-wavelength imaging showing best contrast at 525 nm. The PVA-MBs absolute values of negative zeta potential and anionic mobility when injected from plasma in the pH 12 background electrolyte are higher than those obtained for MBs injected from buffer, consistent with their increased negative charge due to a protein corona coating of the PVA-MBs.

Methane hydrate formation in a water-continuous vertical flow loop with xanthan gum

Hydrate phase transition in drilling fluid is a non-ignorable problem for developing deep-water oil, natural gas and natural gas hydrate resources. Once gas hydrates form during drilling, it will increase the difficulty of wellbore pressure management and flow assurance, which enlarges the risk of hydrate blockage and causes serious property damage and casualties. Methane hydrate formation experiments are conducted in xanthan gum (XG) aqueous solution to mimic the drilling fluid flowing condition in a vertical flow loop. The experiments reveal that the hydrate formation process is a mass transfer process and experiences four different hydrate formation periods, because of the kinetics formation and slough of hydrate shells. The subcooling temperature has a weaker impact on the hydrate formation than the flow velocity and XG. The increase of flow velocity can enhance the hydrate formation rate in drilling fluid but the increase of XG concentration can inhibit the hydrate formation. The influence mechanisms of hydrate shell kinetic slough, flow velocity and XG concentration on hydrate formation are analyzed and discussed in detail. We built a mass-transfer hydrate formation model based on the mechanism of methane molecule diffusing from gas phase to liquid phase. The empirical overall mass transfer coefficient is introduced involving the influence of hydrate shell kinetic slough, flow velocity and XG concentration. In model validation, the maximum discrepancy of the developed model decreases from 146.85% to 11.03% after using the overall mass transfer coefficient.

Modeling and Mitigation of Multiloops Related Device Overvoltage in Three-Level Active Neutral Point Clamped Converter

This article establishes an analytical model for the device drain–source overvoltage related to the two loops in three-level active neutral point clamped (3L-ANPC) converters. Taking into account the nonlinear device output capacitance, two common modulation methods are investigated in detail. The results show that the line switching frequency device usually has higher overvoltage, and the switching speed of the high switching frequency device is not strongly influenced by the multiple loops. By keeping the nonactive clamping switch off , the effect of the nonlinear device output capacitance can be significantly mitigated, which helps reduce the overvoltage. Moreover, the loop inductance can be reduced with vertical loop layout and magnetic cancellation in the printed circuit board and busbar design. A 500-kVA 3L-ANPC converter using silicon carbide mosfet s was built and tested. The experimental results validate the overvoltage model of the two modulation methods as well as the busbar design. With the nonactive clamping switch off , the overvoltage of both the high and line switching frequency devices is significantly reduced, which helps achieve higher switching speed.

Dental midline correction using a cantilever spring: A novel approach

A 13-year-old patient presented with Angle's Class II subdivision right malocclusion with anterior crowding, protruded lower incisors, and a lower arch that was skewed to the left. A morphological lower midline shift of 3 mm to the left was detected. Following extraction of the upper and lower first premolars, full-arch 0.022” MBT™ appliances were placed in both arches. A 0.018” × 0.025” stainless steel archwire was split into two posterior segments and an anterior segment from the right lateral incisor to the left canine including an open vertical helical loop extending apically toward the center of resistance of the consolidated anterior segment. Subsequently, a 0.017” × 0.025” titanium–molybdenum alloy cantilever spring from the right first molar auxiliary tube was bent buccally and connected to the loop with an elastomeric chain to achieve lower midline correction by translation. Midline correction with the use of segmented-wire technique and cantilever spring provides an effective method of incisor movement by translation with minimal side effects.

Void Fraction Measurement in a Gas-Liquid Swirling Flow Using an Ultrasonic Sensor

In this article, we propose a novel ultrasonic technique to measure the gas void fraction in a liquid-gas intermittent swirling flow. The method converts the liquid film thickness measurement to a gas void fraction value considering a symmetrical flow pattern. We propose the use of the first echo peak instead of the standard maximum echo peak to estimate the liquid film thickness. The results are compared with a wire-mesh sensor, a reference for gas void fraction measurement, in a 1-inch inner-diameter vertical flow loop. A Root-Mean-Square-Deviation (RMSD) of 2.87% was observed between the proposed ultrasonic method and the reference sensor. An improvement of 6.06% if compared to the standard film thickness method (8.93%). The studied cases show that our method improves the use of ultrasound for gas void fraction measurement in a gas-liquid swirling flow.

Positive and negative exchange bias in maghemite nanoparticles

Maghemite nanoparticles were synthesized using sol–gel method. The structural study of the samples was done using XRD technique. Zero-field-cooled (ZFC) and field-cooled (FC) magnetization versus applied field (M−H) measurements were conducted between −5 T and +5 T at several temperatures and several field cooled values. The XRD study revealed that the average diameter of the nanoparticles to be around 20 nm. XRD patterns show mainly maghemite phase with very slight hematite phase. The coercively was found to decrease sharply with temperature up to 200 K above which it remains almost constant. Negative and positive horizontal exchange bias was obtained in the ZFC state and only negative exchange bias was obtained at all field cooled values. The magnitudes of the exchange bias were found to decrease sharply with temperature and disappearing above 100 K. Negative and positive vertical loop shifts were obtained in the ZFC state and only positive loop shifts were obtained at all field cooled values. The magnitudes of the loop shifts were found to decrease sharply with temperature and disappearing above 50 K. These results are discussed and attributed mainly to the exchange coupling between the maghemite (ferrimagnetic) and hematite (antiferromagnetic) phases in the nanoparticle system.

Students making sense of motion in a vertical roller coaster loop

Describing the motion in a vertical roller coaster loop requires a good understanding of Newton’s laws, vectors and energy transformation. This paper describes how first-year students try to make sense of force and acceleration in this example of non-uniform circular motion, which was part of a written exam. In addition to an analysis of the exam solutions by about 60 students, a group interview was performed a couple of weeks later with four students, who had all passed the exam. The interview allowed the students to reflect on assumptions made and information missed.

In-field performance evaluation and economic analysis of residential ground source heat pumps in heating operation

The objective of this study is to investigate the field performance, economic benefits, and environmental impact of ground source heat pumps (GSHPs) for residential space heating compared with conventional natural gas furnaces in a severely cold climate. A total of 32 residential houses with 16 vertical and 16 horizontal loop GSHPs in Iowa, U.S. were included in this study. The required heating energy in each house was estimated by using the heating degree-day (HDD) method and the building characteristics obtained during the on-site energy audits. The monthly GSHP electricity use in each house was collected over two consecutive heating seasons. Based on the estimated heating energy and the monthly GSHP electricity consumption, the coefficient of performance (COP) was derived for each unit on a monthly basis over the dominant heating period. Results showed that the median values in the calculated COP were 2.8 for both horizontal and vertical loop systems. The calculated COPs were found to be 30%–124% of the nominal values for horizontal systems and 46%–110% for vertical systems, with an average being 80% of the nominal value for both horizontal and vertical systems. In addition, 28 out of 32 GSHPs showed lower calculated COPs compared with the nominal values. The economic analysis showed 44–86% savings in energy expenses as a result of using GSHPs in place of conventional natural gas furnaces, with median savings being 70–77% depending on the electricity rates. The environmental analysis showed 23%–61% CO2 emission reduction with a median of 45% compared with natural gas furnaces. These results quantified the economic and environmental benefits of using GSHPs in Iowa, U.S., which provided essential information for policy making and incentive program development. Also, the developed analytical approach to determining the field performance of GSHPs is suitable for large-scale, long-term GSHP performance evaluation given its minimum requirement on field measurements and readily available utility data.

Evaluation of a Simplified Loops System for Emergency Rescue Lifting of the Stranded or Recumbent Horse.

Simple SummaryHorses, once stranded or recumbent, can hurt themselves and endanger the personnel trying to rescue them. Successful rescuing of these horses often requires emergency lifting. The objective of this study is to describe a new sling system for short-term lifting of horses. This simple system, called here the Loop Vertical Lift System, or Loops System, utilizes commercially available, and reasonably priced equipment that when used correctly may save lives of stranded horses needing emergency rescue and short-term lifting.Stranded and recumbent equids often require emergency rescue, and a successful rescue often requires vertical lifting of the animal. Currently, the devices used for vertical lifting of equids are not readily available at an incident or urgent situation. The current study describes and evaluates the use of a simple lift device utilizing commercially available, and reasonably priced, equipment. The system, referred to as the Loop Vertical Lift System or Loops System, is basically composed of four round slings placed in such a way that utilizes the skeletal system for support. The study demonstrates the lifting of six standing, sedated adult horses for 3 min without adverse effects. In conclusion, this novel lift system is an affordable, practical and quick alternative to rescue a stranded or recumbent horse that requires a brief vertical lift of the animal. In contrast, for longer-term lifting and support, other devices such as the UC Davis Large Animal Lift, the Anderson Sling Support Device, or the Animal Rescue and Transport Sling (ARTS) should be used as deemed appropriate.

Comparative Evaluation of the Force and Load Deflection Rate for Different Loop Springs with Varying Designs, Wire Dimensions, and Materials: A Finite Element Method Study

Objective: To evaluate and compare the force and load deflection rate generated by differing unit displacement through 1 to 4 mm of springs that vary in design (Double Delta Closing Loop, Double Vertical T Crossed Closing Loop, Double Vertical Helical Closing Loop and Ricketts Maxillary Retractor), constituting wire materials (stainless steel and beta titanium), and wire dimensions (0.017" × 0.025" and 0.019" × 0.025"). Materials and methods: Computer-assisted design (CAD) model of the said loop springs was created and converted to the finite element method (FEM). The boundary conditions assigned were restraining anterior segment of the loops in all the 3 axes and displacement of the posterior segment progressively only along the x-axis in increments of 1, 2, 3, and 4 mm. Force and load deflection rate were calculated for each incremental displacement. Results: For all loop designs, force and load deflection rate increased with incremental displacement. Loop springs of beta titanium and 0.017" × 0.025" dimension showed lesser force and load deflection rate than those of stainless steel and 0.019" × 0.025", respectively. Ricketts Maxillary Retractor showed the least force and load deflection rate. Comparable force and load deflection values were found for 0.017" × 0.025" Double Vertical T Crossed Loop and 0.019" × 0.025" Double Vertical Helical Closing Loop. Conclusions: Variations in wire dimensions, materials, and designs have a profound effect on force and load deflection rate of the different loop springs studied.

Simulation of the dynamic behavior of a rectangular single-phase natural circulation vertical loop with asymmetric heater

The critical capability of Natural circulation flow for the removing heat has been demonstrated and are widely used in the industry particularly received notable attention to improve passive safety and decrease running expenses in the latest version of nuclear reactors. Among the different type of natural circulation systems, the distinctive characteristics of single-phase natural circulation loops (NCLs), those involved even in very simplified models, are identified to be characterized by a deep complexity of chaotic behavior. In this investigation the experimental data gathered in the AKIAU-R-1P loop, a rectangular single-phase NCL through a test operation, are compared with the results of simulations obtained by one-dimensional RELAP5/Mod3.2 code and three-dimensional ANSYS FLUENT 17.1 computational fluid dynamic (CFD) code. The experimental data, including time histories of the temperature difference over the heater, was almost similar to the predicted simulation results of RELAP5 and ANSYS FLUENT. The RELAP5 code has the capability of prediction the status at low power levels (stable mode) with adequate correctness rather than CFD code whereas when the system is unstable at higher power, CFD indicates further oscillatory behavior in comparison with RELAP5 code and experimental data. The CFD code was functional in presenting the diffusive phenomena which could not be estimated by the RELAP5 one-dimensional model.

Evaluation of short folded dipole antennas as receive elements of ultra-high-field human head array.

To improve the receive (Rx) performance of a human head transceiver (TxRx) array at 9.4T without compromising its transmit (Tx) performance, a novel 16-element array was developed, constructed, and tested. We designed and constructed a phased array, which consists of 8 TxRx surface loops placed in a single row and circumscribing a head, and 8 Rx-only short folded dipole antennas. Dipoles were positioned along the central axis of each transceiver loop perpendicular to its surface. We evaluated the effect of Rx dipoles on the Tx efficiency of the array and maximum local specific absorption rate (SAR) as compared to the array of 8 surface loops only. We also compared the new array to a 16-channel array of the same size consisting of 8 TxRx surface loops and 8 Rx-only vertical loops in terms of Tx efficiency, SAR, and signal-to-noise ratio (SNR). The new array improves both peripheral (up to 2 times) and central (1.17 times) SNR as compared to the 16-element array of the same geometry consisting of 8 TxRx surface loops and 8 Rx-only vertical loops. We demonstrated that an addition of actively detuned Rx-only dipole elements produces only a small decrease (~7%) of the transmit field and a small increase (<7%) of the maximum local SAR. As a proof of concept, we developed and constructed a prototype of a 9.4T (400 MHz) head array consisting of 8 TxRx surface loops and 8 Rx-only short optimized folded dipoles. We demonstrated that at ultra-high field, dipoles outperformed Rx-only vertical loops in vivo.

Double-row 18-loop transceive-32-loop receive tight-fit array provides for whole-brain coverage, high transmit performance, and SNR improvement near the brain center at 9.4T.

To improve the transmit (Tx) and receive (Rx) performance of a human head array and provide whole-brain coverage at 9.4T, a novel 32-element array design was developed, constructed, and tested. The array consists of 18 transceiver (TxRx) surface loops and 14 Rx-only vertical loops all placed in a single layer. The new design combines benefits of both TxRx and transmit-only-receive-only (ToRo) designs. The general idea of the design is that the total number of array elements (both TxRx and Rx) should not exceed the number of required Rx elements. First, the necessary number of TxRx loops is placed around the object tightly to optimize the Tx performance. The rest of the elements are loops, which are used only for reception. We also compared the performance of the new array with that of a state-of-the-art ToRo array consisting of 16 Tx-only loops and 31 Rx-only loops. The new array provides whole-brain coverage, ~1.5 times greater Tx efficiency and 1.3 times higher SNR near the brain center as compared to the ToRo array, while the latter delivers higher (up to 1.5 times) peripheral SNR. In general, the new approach of constructing a single-layer array consisting of both TxRx- and Rx-only elements simplifies the array construction by minimizing the total number of elements and makes the entire design more robust and, therefore, safe. Overall, our work provides a recipe for a Tx- and Rx-efficient head array coil suitable for parallel transmission and reception as well as whole-brain imaging at UHF.

The head morphology of Micromalthus debilis (Coleoptera: Micromalthidae) - an archostematan beetle with an unusual morphology and a unique life cycle

Cephalic features of Micromalthus debilis were examined and described in detail for the first time. The head displays several seemingly plesiomorphic features compared to other extant species of Archostemata, especially representatives of Cupedidae and Ommatidae. Cephalic protuberances characteristic for species of these two families are missing and antennal grooves are also absent. The surface of the head capsule is largely smooth, without the characteristic tubercles found in stemgroup beetles and ommatid and cupedid species. Cuticular scales, probably ancestral for Archostemata and possibly for Coleoptera, are also completely absent. The arrangement of three mandibular teeth in a vertical row and an immobilized labrum are derived features shared with Ommatidae. The maxillary endite lobes are absent, as in the very small Crowsoniella relicta (Crowsoniellidae). Like in all other examined archostematan species, mandibular molae and prosthecae are missing. The simplified maxillae apparently play no role in the food uptake but rather function as accessory “ventral antennae”. Derived features include the partly reduced maxillary musculature and lack of extrinsic labial muscles. Apomorphies of the digestive tract include the sclerotized median protuberances of the anterior epipharynx and hypopharynx, and the presence of a vertical anterior pharyngeal loop and a subcerebral postpharyngeal pouch. The tentorium is strongly reduced. Consequently, all antennal muscles originate from the head capsule. A very unusual and possibly plesiomorphic feature is the presence of a short salivary tube and two associated muscles. This is a unique condition in Coleoptera as far as known at present. Structural features suggest that Micromalthus probably feeds on wood infested with fungi. A robust phylogenetic evaluation of anatomical features is presently not possible due to the lack of data for Crowsoniella (Crowsoniellidae) and Sikhotealinia zhiltzovae (Jurodidae). Moreover, phylogenetic and evolutionary interpretations are impeded by possible effects of vestigialization of adults possibly resulting from endosymbionts (e.g. Wolbachia, Rickettsiales).

A Pilot Study on Geothermal Heat Pump (GHP) Use for Cooling Operations, and on GHP Site Selection in Tropical Regions Based on a Case Study in Thailand

In order to reduce electricity consumption, the vertical loop geothermal heat pump (GHP) system coupled with a normal air conditioner was installed in an experimental room in the Parot Racha Building, Chulalongkorn University, Bangkok, Thailand for a comparative, long-term measurement program. The decrease in electricity consumption was approximately 30%. On the basis of the data derived from our measurements, the underground temperature seemed to be consistent and lower than the average outside air temperature, over two years. The underground system consisted mainly of two 50-m-long drilling wells and pipes with a total length of 170 m. The well performance was not examined, but both soil and groundwater aquifer (Bangkok aquifer) at 25 to 50 m. could be utilized for the cooling operation. Moreover, the major controlling factors of electricity consumption were found to be the outside air temperatures and the underground water circulation temperatures. In addition, we considered the geology, underground temperature, and aquifer of Bangkok concluding that almost all Bangkok areas are suitable for GHP installation, except for those where the subsurface temperature is too high compared with the outside air temperature.

A first application of a marine inductive source electromagnetic configuration with remote electric dipole receivers: Palinuro Seamount, Tyrrhenian Sea

ABSTRACTWe study a new marine electromagnetic configuration that consists of a ship‐towed inductive source transmitter and a series of remote electric dipole receivers placed on the seafloor. The approach was tested at the Palinuro Seamount in the southern Tyrrhenian Sea, at a site where massive sulphide mineralization has been previously identified by shallow drilling. A 3D model of the Palinuro study area was created using bathymetry data, and forward modelling of the electric field diffusion was carried out using a finite volume method. These numerical results suggest that the remote receivers can theoretically detect a block of shallowly buried conductive material at up to ∼100 m away when the transmitter is located directly above the target. We also compared the sensitivity of the method using either a horizontal loop transmitter or a vertical loop transmitter and found that when either transmitter is located directly above the mineralized zone, the vertical loop transmitter has sensitivity to the target at a farther distance than the horizontal loop transmitter in the broadside direction by a few tens of metres. Furthermore, the vertical loop transmitter is more effective at distinguishing the seafloor conductivity structure when the vertical separation between transmitter and receiver is large due to the bathymetry. As a horizontal transmitter is logistically easier to deploy, we conducted a first test of the method with a horizontal transmitter. Apparent conductivities are calculated from the electric field transients recorded at the remote receivers. The analysis indicates higher apparent seafloor conductivities when the transmitter is located near the mineralized zone. Forward modelling suggests that the best match to the apparent conductivity data is obtained when the mineralized zone is extended southward by 40 m beyond the zone of previous drilling. Our results demonstrate that the method adds value to the exploration and characterization of seafloor massive sulphide deposits.

Excitation of vertical coronal loop oscillations by impulsively driven flows

Context. Flows of plasma along a coronal loop caused by the pressure difference between loop footpoints are common in the solar corona. Aims. We aim to investigate the possibility of excitation of loop oscillations by an impulsively driven flow triggered by an enhanced pressure in one of the loop footpoints. Methods. We carry out 2.5D magnetohydrodynamic (MHD) simulations of a coronal loop with an impulsively driven flow and investigate the properties and evolution of the resulting oscillatory motion of the loop. Results. The action of the centrifugal force associated with plasma moving at high speeds along the curved axis of the loop is found to excite the fundamental harmonic of a vertically polarised kink mode. We analyse the dependence of the resulting oscillations on the speed and kinetic energy of the flow. Conclusions. We find that flows with realistic speeds of less than 100 km s−1 are sufficient to excite oscillations with observable amplitudes. We therefore propose plasma flows as a possible excitation mechanism for observed transverse loop oscillations.

Exploring ferroelectric and magnetic properties of Tb-substituted m = 5 layered Aurivillius phase thin films

Here, we report the effect of A-site substitution of Tb at the expense of Bi on the ferroelectric and magnetic properties in m = 5 layered 2-D Aurivillius Bi6Ti3Fe2O18 thin films. The nominal stoichiometry of the prepared compound is Tb0.40Bi5.6Fe2Ti3O18, Tb0.90Bi5.1Fe2Ti3O18, and Bi6Ti3Fe2O18. Phase examination reveals that only 0.40 mol. % is successfully substituted forming Tb0.40Bi5.6Fe2Ti3O18 thin films. Lateral and vertical piezoresponse switching loops up to 200 °C reveal responses for Bi6Ti3Fe2O18, Tb substituted Tb0.40Bi5.6Fe2Ti3O18, and Tb0.90Bi5.1Fe2Ti3O18 thin films along the in-plane (±42.31 pm/V, 88 pm/V and ±134 pm/V, respectively) compared with the out-of-plane (±6.15 pm/V, 19.83 pm/V and ±37.52 pm/V, respectively). The macroscopic in-plane polarization loops reveal in-plane saturation (Ps) and remanence polarization (Pr) for Bi6Ti3Fe2O18 of ±26.16 μC/cm2 and ±22 μC/cm2, whereas, ±32.75 μC/cm2 and ±22.11 μC/cm2, ±40.30 μC/cm2 and ±28.5 μC/cm2 for Tb0.40Bi5.6Fe2Ti3O18 and Tb0.90Bi5.1Fe2Ti3O18 thin films, respectively. No ferromagnetic signatures were observed for Bi6Ti3Fe2O18 and Tb0.40Bi5.6Fe2Ti3O18. However, a weak response was observed for the Tb0.90Bi5.1Fe2Ti3O18 at 2 K. Microstructural analysis of Tb0.90Bi5.1Fe2Ti3O18 revealed that it contains 4 vol. % Fe:Tb rich areas forming FexTbyOz, which accounts for the observed magnetic moment. This study demonstrates the importance of thorough microstructural analysis when determining whether magnetic signatures can be reliably assigned to the single-phase system. We conclude that Tb0.40Bi5.6Fe2Ti3O18 and Tb0.90Bi5.1Fe2Ti3O18 samples are not multiferroic but demonstrate the potential for Fe-RAM applications.

Natural convection heat transfer characteristics of molten salt with internal heat generation

Molten salt is a promising heat transfer fluid with its high heat capacity, high boiling point, and chemical stability. In liquid fueled molten salt reactors and spent fuel reprocessing unit, molten salt carries heat generating fuel itself in a liquid state. To investigate the natural convection heat transfer performance of molten salt, a vertical heater vertical cooler rectangular loop filled with chloride salt containing liquid fuel, NaCl-KCl-(Pu, 238U)Cl3, is simulated using an open source CFD package, OpenFOAM under various heat input conditions; external heat flux, internal heat generation (IHG), and a combined heat input type condition. Different aspects of natural convection heat transfer according to heat input condition are found for same amount of total heat. The external heat flux condition generates a high temperature gradient near the heater wall with very thin thermal boundary layer due to the low thermal conductivity of molten salt. On the other hand, the IHG condition has a relatively flat temperature profile from its uniform volumetric heating. Due to the different behaviors of temperature evolution, local upward flow is formed only at the wall region under the heat flux condition, but global natural circulation flow is promoted under IHG condition. The combined type condition is largely dependent on how much heat exists in heat flux type, which strongly influences local heat and fluid phenomena in natural convection heat transfer. Molten salt has a high dependence on the heat input condition from its thermo-physical properties. Therefore, the distinct characteristics of molten salt and heat input conditions should be considered, when designing and analyzing the molten salt systems with both external and internal heating conditions.

Pressure Drop Measurements in Venturi Meters of Different Beta Ratios for Oil–Water Flow Experiments

The performances of the venturi meters for oil–water flow under real oil well operating conditions were investigated in the present experimental investigation. The pressure drop measurements were studied in Tercom flanged machined venturi meters with a beta ratio ( $$\beta )=0.4$$ , 0.5 and 0.6 for oil–water two-phase flow experiments in a 0.0762 m (3-in.) pipe. The experimental data for different fluid mixture flow rates and water cuts were acquired using a two-phase, large-scale inclinable flow loop. Potable water and Exxsol mineral oil (D80) were used for the single-phase and two-phase oil–water experiments for the three venturi meters. The experiments were conducted for water cuts varying from 0 to 100% in steps of 20%, flow rates ranging from 2000 to 10,000 barrels per day (bpd), and for horizontal and vertical flow loop inclinations ( $$0{^{\circ }}$$ and $$90{^{\circ }}$$ ). Real oil wells flow rates were matched by selecting test liquid flow rates. The experimental results showed that the venturi pressure drop varies as the square of the fluid flow rate for given water cut through the venturi meters studied. For given flow rate and water cut, the venturi pressure drop is inversely proportional to the venturi $$\beta $$ ; however, the venturi pressure drop varies almost linearly with the water cut for a given fluid flow rate. Within the range of test fluid flow rates, the venturi pressure drop measurements were unaffected by the inclination of the three venturi meters studied in the flow loop. This is very important from an application standpoint.