Cylindrical Orifice Research Articles

An Experimental Investigation of the Hydrate Formation Mechanism in the Throttling of Carbon Dioxide-Containing Trace Moisture

Carbon capture, utilization and storage are facilitated through carbon dioxide (CO2) transport. Pipe transportation is the main method for transporting CO2. However, hydrate blockages reduce transport efficiency in the pipelines, and the throttling devices are the main location of hydrate blockages. In this paper, the mechanism of hydrate formation in the throttling of CO2-containing trace moisture was investigated. The throttling device in a pipe was mimicked using a cylindrical orifice plate. The work also studied the effects of moisture content, upstream pressure and upstream temperature on hydrate formation. The results indicate that the Joule–Thomson cooling effect is a key contributor, and promotes the condensation of trace moisture, resulting in the free water necessary for hydrate nucleation. Under the effect of gas flow back-mixing, it is easy for the hydrate to adhere to the inner surface of the pipe behind the orifice plate. When the moisture content in the gas increases from 123 μmol/mol to 1024 μmol/mol, the hydrate induction time decreases from infinity to 792 s. However, the moisture content has no effect on the adhesion strength of the hydrate to the inner surface of the pipe. When the initial upstream pressure increases from 2.0 MPa to 3.5 MPa, the hydrate induction time decreases from infinity to 306 s. When the upstream temperature decreases from 291.15 K to 285.15 K, the hydrate induction time decreases from infinity to 330 s. With the decrease in the initial upstream temperature, the adhesion of hydrate particles to the inner surface of the pipe is promoted. This study provides experimental evidence for the characteristics of hydrate formation in the process of CO2 throttling.

Vortex-enhanced jet impingement and the role of impulse generation rate in heat removal using additively manufactured synthetic jet devices

This article presents an approach to the design and fabrication of synthetic jet devices (SJDs) using rapid prototyping via additive manufacturing, marking the first study to employ this method for such devices. This manufacturing technique empowers researchers with complete design freedom, enabling the production of ultra-thin SJDs—as thin as 4 mm—without mechanical fasteners and facilitating the rapid fabrication of multiple devices with varying geometries. To showcase the potential of this method, SJDs with conical and cylindrical cavities and orifices ranging from 1.6 mm to 7 mm were designed, fabricated, and tested.These devices achieved air jet exit velocities exceeding 106 m/s using a single piezoelectric diaphragm—among the highest reported in the literature—validating the effectiveness of this manufacturing approach. This high jet velocity is significant for practical applications requiring efficient thermal management, such as cooling high-power-density electronics, where compact and energy-efficient solutions are essential. Beyond achieving high velocities, it was revealed that maximizing jet velocity alone is not always optimal for heat removal. The hydrodynamic impulse generation rate was introduced as a more significant factor influencing heat transfer performance. By fabricating and testing multiple SJDs with different geometries, it was demonstrated that the impulse generation rate, which accounts for both jet velocity and flow rate, better correlates with enhanced heat transfer capabilities than jet velocity alone. This insight addresses an often-overlooked parameter in SJD design and has substantial implications for optimizing heat removal performance. Moreover, lumped element modeling, tuned solely on diaphragm deflection behavior, accurately predicted device performance and was validated using a hotwire anemometer. This model effectively characterizes center-axis orifice devices and confirms its applicability to thin-cavity designs, providing a valuable tool for future SJD development. Despite moderate volume flow rates (0.2 to 0.8 m3/h), the fabricated SJDs delivered significant improvements in heat transfer. Compared to natural convection, these devices achieved over 13 times greater heat removal rates, with an average heat transfer coefficient exceeding 120 W/m2·K over a 30 mm × 30 mm heated surface. These findings demonstrate the practicality and effectiveness of vortex-enhanced synthetic jet impingement for targeted and efficient cooling of localized hot spots. This approach offers multiple advantages over traditional rotary cooling systems like fans, including increased reliability, lower profile, while consuming less than 100 mW. The ability to rapidly prototype and optimize SJDs using additive manufacturing accelerates research and development in this field, paving the way for advanced thermal management solutions in real-world applications.

Derivation of analytic formulae for several resonance frequencies of the SparkJet actuator

Building on previous research that emphasized the importance of focusing on resonance frequencies for a fundamental understanding of the thrust and complex internal flow phenomena of the SparkJet actuators, this study theoretically derives analytic formulae for several important resonance frequencies. The research addresses the typical configuration of the SparkJet actuators, which consists of a cylindrical cavity and orifice connected by a conical converging nozzle. While the resonance frequencies of the SparkJet actuators can be obtained by solving the eigenvalue problem presented in previous studies, this eigenvalue problem, despite being a typical boundary value problem in the form of an elliptic partial differential equation, is challenging to solve using conventional numerical methods such as iterative methods, because the eigenvalue is included as an unknown in the operator. Consequently, Boundary Element Method (BEM) or methods using the Green functions have been proposed to obtain numerical solutions, but these still require handling large matrix data, resulting in significant computational costs and memory consumption. To overcome this, the current study first simplifies the eigenvalue problem using the conformal mapping presented in previous research. Then, referencing prior studies that claim that three types of resonance frequencies (Helmholtz resonance frequency and resonance frequencies representing streamwise or radial directional oscillation) significantly affect the thrust of the SparkJet actuators, characteristics of these frequencies are mathematically defined. Using these mathematical characteristics, the study derives the asymptotic and approximate solutions of the simplified eigenvalue problem, from which the resonance frequencies are obtained. The analytic formulae proposed in this study theoretically explain the already known geometric tendencies of the resonance frequencies and reveal new geometric factors influencing resonance frequencies, which were previously unknown. This approach is expected to facilitate obtaining several important resonance frequencies of the SparkJet actuator more promptly and accurately and to provide a deeper understanding of the nature of the complex oscillation phenomena inside the actuator.

Study of the effect of cavitation flow patterns in diesel injector nozzles on near-field spray atomization characteristics using a LES-VOF method

The spray atomization process plays a critical role in achieving high efficiency and reducing emissions in internal combustion engines. The fuel injection atomization process, especially the spray primary atomization process, is significantly influenced by turbulent flow and cavitation phenomena within the nozzle. In this study, based on the coupled large eddy simulation(LES) and a volume-of-fluid (VOF)method, the effects of four typical nozzle internal flow patterns on the spray primary breakup in the near-nozzle region were investigated. To realize this objective, the generation of four distinct flow patterns was accomplished through the design and construction of corresponding nozzle structures: (1) nearly single-phase flow in a tapered-orifice nozzle with low orifice location, (2) strong geometry-induced sheet cavitation flow with sheet region extending to the nozzle orifice exit in a normal cylindrical orifice, (3) vortex-induced string cavitation flow in a tapered-orifice nozzle with relative high orifice location, and (4) geometry-induced sheet cavitation is partially suppressed while it is enhanced in the orifice region close to exit in a convergent-divergent orifice. The numerical results unequivocally reveal that the initial atomization of the spray exhibits remarkable efficacy in the case of the conventional cylindrical nozzle, characterized by internal regions of substantial sheet cavitation, despite a relatively minimal flow discharge coefficient. Conversely, the normal tapered-orifice nozzle, lacking significant cavitation, demonstrates a larger flow discharge coefficient, yet its initial atomization performance is notably suboptimal.It is worth noting that the appropriate vortex-induced cavitation in the nozzle can correspond a higher flow rate with a thin string-type cavitation and simultaneously a better spray atomization quality with a strong vortex flow. Also it is concluded that a convergent-divergent nozzle with appropriate transition location can achieve strong atomization .

Cylindrical orifice testing in laminar flow with the orifice diameter ratio β = 0.5

The paper presents the results of an experimental study of a cylindrical orifice with the orifice diameter ratio β = 0.5 and the flow opening length-to-diameter ratio L/d = 1, with hydraulic oil flowing in the DN50 measuring channel. The measurements of the values characterising the oil flow were made in the laminar flow regime, for the Reynolds numbers ranging between Re = 100 to 950. Based on the experimental tests, standard flow characteristics were created for four kinematic viscosity values in the range of 13.4–33.3 cSt, for which the average value of the discharge coefficient C in the tested flow rate range of qv < 0.5 dm3/s was determined.

Large eddy simulation of highly compressible film cooling in transonic crossflow

Large eddy simulation is performed to study the thermal energy transport and mixing process of compressible film cooling in the fully-turbulent high-Mach-number crossflow. Three Mach numbers, 0.8, 1.2, and 1.4, based on the bulk crossflow velocity, are adopted. And the influence of both the compressibility and shock waves on the transverse jet from cylindrical orifices is discussed in detail. The results reveal that the effects of compressibility should be distinguished from shocks in supersonic flows. The compressibility effect strengthens the jet penetration and lateral spreading by increasing the energy contained in the large-scale coherent structures. The mixing of the jet is enhanced by the strong compressibility in the near field whether shocks exist or not. When the crossflow transits from the subsonic to the supersonic state, the effect of shock waves becomes more significant than that of the compressibility. Various interactions between shocks, coherent structures, and thermal energy transport are analyzed in this study. The results show that the appearance of the separation shock and bow shock reduces the jet penetration and strengthens its interaction with the bottom wall. The generation of this type of shock system suppresses the flow separation on the leeward side of the jet, which results in a higher cooling effectiveness in the jet near field. The incident oblique shock wave also induces lifting of the jet trajectory in the far-field region as a result of the intensified separation trend. In the highly compressible film cooling process with great temperature difference, the advection transport associated with turbulent motion, rather than the one associated with mean motion, turns out to dominate the thermal energy transfer in general. Moreover, the counter gradient behavior of this thermal energy transport in compressible turbulence is also shown.

ANÁLISIS CFD DE CONTROL DE FLUJO MEDIANTE UNA VÁLVULA ESFÉRICA

Flow control in piping systems is present in many engineering applications and is carried out by different components. In particular, ball valves consist of a plug with a cylindrical orifice that regulates the flow through rotation, modifying the effective passage section. In the present work, this type of device is studied using Computational Fluid Dynamics(CFD). The simulations are carried out using the SimScale calculation platform, based on the free OpenFOAM software. The main objective of this analysis is to set and validate a numerical tool to predict the relationship between the opening percentage and the pressure loss for normalized valves, analyzing the flow structures developed in the vicinity of the plug. The models used are validated in axisymmetric problems of conduits with constant section and with a localized structure, comparing with the analytical solution and with numerical simulations, respectively. Then the case of a real ball valve in a turbulent regime at different openings is studied, comparing the results with experimental data and with numerical simulations carried out by other authors. A good agreement of the pressure loss coefficient is observed for each of the opening angles studied, verifying its independence on the Reynolds number.

A numerical analysis of particulate matter control technology integrated with HVAC system inlet design and implications on energy consumption

This paper examines and outlines the development of a novel inlet for an air handling unit (AHU) which controls PM concentration entering mechanically ventilated buildings. The aspiration efficiency reducer (AER), can reduce the ambient PM concentrations drawn into a building ventilation system. The AER device incorporates an array of cylindrical tubed orifices, which create conditions for potential improved indoor air quality (IAQ) and energy savings. Prototypes were designed by reverse-engineering the aspiration efficiency (AE) concept, creating new inlets for AHUs using Computational Fluid Dynamics. This approach helps achieve low AE values and reduce PM concentrations entering the AHU and filter loading rates. 3D k-ω SST models were used to simulate particle laden fluid flow around an AHU with AER attachments. The investigation found that the engineering of wind flow around the AHU and its inlet resulted in lower levels of particles with diameters ≤10 μm entering the AHU. The difference in AE for particles within the PM10 range for the passive AER prototypes in comparison to a commercial rainhood ranged from 5 to 35% for various inlet designs. This translated into increased energy savings of 15.2–20.6% and extended fabric filter lifespan of up to an additional 100 hundred days until saturation. The AER has the potential to reduce energy consumption, minimise waste generation and present cost savings whilst improving IAQ, through a reduction in maintenance activities and the number of filter replacements. This novel technology requires low-capital investment to deliver environmental, energy and economic savings in this sector.

A rotating detonation engine using methane-ethylene mixture and air

Most of hydrocarbon fuels often have larger methane numbers than hydrogen. It is more difficult to detonate the mixture of hydrocarbon fuels and air at room temperatures in non-premixed engines since the mixing is slower than hydrogen-air mixing and the mixing is slower at lower temperatures. Ethylene–air rotating detonation operations have been successful, but methane-ethylene-air mixture at room temperatures is more difficult to detonate for rotating detonation engines since methane is more chemically stable. The hollow combustor channel here had an outer diameter of 220 mm and a length of 163 mm. Methane-ethylene mixture was injected axially into the combustor from cylindrical orifices in a diameter of 0.8 mm, and air was injected radially through a convergent-divergent circular channel with a throat width of 0.8 mm. Non-premixed rotating detonation waves were obtained for methane-ethylene-air mixture at total temperatures of 280–285 K in the present study. Both high-speed images and pressure traces show that three-wave mode has a higher detonation speed than five-wave mode. The rotating detonation speed is increased with the increased detonation height.

Large Eddy Simulation Investigations of Periodic Cavitation Shedding With Special Emphasis on Three-Dimensional Asymmetry in a Scaled-Up Nozzle Orifice

Abstract The periodic shedding of cloud cavitation in a nozzle orifice has a significant influence on the flow field and may have destructive effects. Most of the existing research on the shedding of cloud cavitation in an orifice is based on experimental visualization with a focus on the two-dimensional (2D) motion of the re-entrant jet and the shedding mechanism. However, the actual cloud cavitation shedding in an orifice is a complex three-dimensional (3D) process. Some limited signs of three-dimensionality and asymmetry in cylindrical orifices have been detected recently, but the 3D shedding characteristics remain unclear. In this paper, the cavitation regimes and periodic shedding process in the scaled-up nozzle orifice used by the Stanley experiment were simulated with large eddy simulation (LES). The re-entrant jet and periodic shedding mechanism, as well as, the shedding frequency, were analyzed from 2D and 3D perspectives. The main results show that the simulated cavitation regimes and the 2D periodic shedding mechanism agree fairly well with the experimental observations, but more 3D features are revealed. By analyzing the 3D shedding process and the three-dimensionality caused by the inclination of the closure line, the three-dimensional asymmetric shedding mode with phase difference π is revealed. Based upon this finding, the shedding frequency, and Strouhal number are calculated. The corresponding relationships between shedding frequencies and the frequency peaks of the power spectrum density (PSD) for pressure fluctuations are also confirmed. These results extend the understanding of the unsteady cavitating flow within nozzle orifices from 2D to 3D patterns.

Combustion Characteristics in Rotating Detonation Engines

A lot of studies on rotating detonation engines have been carried out due to the higher thermal efficiency. However, the number, rotating directions, and intensities of rotating detonation waves are changeful when the flow rate, equivalence ratio, inflow conditions, and engine schemes vary. The present experimental results showed that the combustion mode of a rotating detonation engine was influenced by the combustor scheme. The annular detonation channel had an outer diameter of 100 mm and an inner diameter of 80 mm. Air and hydrogen were injected into the combustor from 60 cylindrical orifices in a diameter of 2 mm and a circular channel with a width of 2 mm, respectively. When the air mass flow rate was increased by keeping hydrogen flow rate constant, the combustion mode varied. Deflagration and diffusive combustion, multiple counterrotating detonation waves, longitudinal pulsed detonation, and a single rotating detonation wave occurred. Both longitudinal pulsed detonation and a single rotating detonation wave occurred at different times in the same operation. They could change between each other, and the evolution direction depended on the air flow rate. The operations with a single rotating detonation wave occurred at equivalence ratios lower than 0.60, which was helpful for the engine cooling and infrared stealth. The generation mechanism of longitudinal pulsed detonation is developed.

Scalable Heat Transfer Characterization on Film Cooled Geometries Based on Discrete Green’s Functions

Abstract The aerothermal characterization of film-cooled geometries is traditionally performed at reduced temperature conditions, which then requires a debatable procedure to scale the convective heat transfer performance to engine conditions. This paper describes an alternative engine-scalable approach, based on Discrete Green’s Functions (DGF) to evaluate the convective heat flux along film-cooled geometries. The DGF method relies on the determination of a sensitivity matrix that accounts for the convective heat transfer propagation across the different elements in the domain. To characterize a given test article, the surface is discretized in multiple elements that are independently exposed to perturbations in heat flux to retrieve the sensitivity of adjacent elements, exploiting the linearized superposition. The local heat transfer augmentation on each segment of the domain is normalized by the exposed thermal conditions and the given heat input. The resulting DGF matrix becomes independent from the thermal boundary conditions, and the heat flux measurements can be scaled to any conditions given that Reynolds number, Mach number, and temperature ratios are maintained. The procedure is applied to two different geometries, a cantilever flat plate and a film-cooled flat plate with a 30 degree 0.125 in. cylindrical injection orifice with length-to-diameter ratio of 6. First, a numerical procedure is applied based on conjugate 3D unsteady Reynolds-averaged Navier–Stokes (URANS) simulations to assess the applicability and accuracy of this approach. Finally, experiments performed on a flat plate geometry are described to validate the method and its applicability. Wall-mounted thermocouples are used to monitor the surface temperature evolution, while a 10 kHz burst-mode laser is used to generate heat flux addition on each of the discretized elements of the DGF sensitivity matrix.

Cavitation patterns in high-pressure homogenization nozzles with cylindrical orifices: Influence of mixing stream in Simultaneous Homogenization and Mixing

High-pressure homogenization is the state of the art to produce high-quality emulsions with droplet sizes in the submicron range. In simultaneous homogenization and mixing (SHM), an additional mixing stream is inserted into a modified homogenization nozzle in order to create synergies between the unit operation homogenization and mixing. In this work, the influence of the mixing stream on cavitation patterns after a cylindrical orifice is investigated. Shadow-graphic images of the cavitation patterns were taken using a high-speed camera and an optically accessible mixing chamber. Results show that adding the mixing stream can contribute to coalescence of cavitation bubbles. Choked cavitation was observed at higher cavitation numbers σ with increasing mixing stream. The influence of the mixing stream became more significant at a higher orifice to outlet ratio, where a hydraulic flip was also observed at higher σ. The decrease of cavitation intensity with increasing back-pressure was found to be identical with conventional high-pressure homogenization. In the future, the results can be taken into account in the SHM process design to improve the efficiency of droplet break-up by preventing cavitation or at least hydraulic flip.

On the influence of thermal phenomena during cavitation through an orifice

Thermal properties of cryogenic fluids can profoundly change the nature of cavitation since the fluid pressure drop is not, anymore, the only driving parameter of this phenomenon.In this research, we have conducted experiments inducing cavitation via a cylindrical orifice using Liquid Nitrogen as working fluid and exploring cavitation regimes going from bubbly cavitation to full flashing. Among others, we performed unsteady pressure measurements to derive the speed of sound during cavitation and high-speed imaging to understand the evolution of the two-phase flow along the pipe.In our analysis we use five dimensionless numbers to describe the flow conditions upstream and downstream of the orifice, and the type of transition taking place across the orifice.In this paper, we show that the fluid initial subcooling level ΔTsub upstream of the orifice and the superheat level Rp of the flow downstream of the orifice are two parameters essential to take into account the metastability of the fluid. Therefore, we propose a new semi-empirical model for predicting the effect of the fluid thermal properties on cavitation. Specifically, we define a parameter T which, multiplied by the saturation pressure at the inlet temperature, allows us to estimate the pressure reached at the orifice to cavitate.

Acoustic impedance of a cylindrical orifice

We use matched asymptotics to derive analytical formulae for the acoustic impedance of a subwavelength orifice consisting of a cylindrical perforation in a rigid plate. In the inviscid case, an end correction to the length of the orifice due to Rayleigh is shown to constitute an exponentially accurate approximation in the limit where the aspect ratio of the orifice is large; in the opposite limit, we derive an algebraically accurate correction, depending upon the logarithm of the aspect ratio, to the impedance of a circular aperture in a zero-thickness screen. Viscous effects are considered in the limit of thin Stokes boundary layers, where a boundary layer analysis in conjunction with a reciprocity argument provides the perturbation to the impedance as a quadrature of the basic inviscid flow. We show that for large aspect ratios the latter perturbation can be captured with exponential accuracy by introducing a second end correction whose value is calculated to be in between two guesses commonly used in the literature; we also derive an algebraically accurate approximation in the small-aspect-ratio limit. The viscous theory reveals that the resistance exhibits a minimum as a function of aspect ratio, with the orifice radius held fixed. It is evident that the resistance grows in the long-aspect-ratio limit; in the opposite limit, resistance is amplified owing to the large velocities close to the sharp edge of the orifice. The latter amplification arrests only when the the plate is as thin as the Stokes boundary layer. The analytical approximations derived in this paper could be used to improve circuit modelling of resonating acoustic devices.

Discharge characteristics of drilled throttle orifices in fiber-reinforced plastics for an HLFC system

A series of test campaigns at DLR’s large flow meter (LFM) has been conducted to investigate the discharge characteristics of cylindrical throttle orifices, drilled in fiber-reinforced plastics, with respect to their diameter and manufacturing imperfections. In hybrid laminar flow control (HLFC) applications following the simplified so-called ALTTA concept, those throttle holes interfacing a common plenum to multiple chambers play an important role in regulating the local amount of suction through the porous wing surface. The work performed aims at the further development and industrialized application of HLFC in an aircraft environment. This question is tackled by the industry-oriented drilling of throttle holes into coupon-sized flat samples. Drilling parameters allowing a stable and reproducible process were established through optical inspection. The major experimental findings are discussed in this article alongside some general manufacturing recommendations for throttle holes in HLFC applications.

Rotating detonation engines with two fuel orifice schemes

Hollow combustors without centerbodies are becoming popular for rotating detonation engines. The present experimental study compares detonation and pressure gain performances of hollow combustors with two fuel orifice schemes to choose a better one. Hydrogen and air sources at room temperatures of 280–285 K are used as propellants. The combustors are optically accessible by embedding a piece of quartz glass in the outerbody. The hollow combustor channel here has an outer diameter of 100 mm. Fuel is injected into the combustor from 150 cylindrical orifices in a diameter of 0.8 mm or 90 orifices in a diameter of 2 mm, and air is injected through a circular channel with a throat width of 1 mm. Results show that the hollow combustor with 150 cylindrical orifices in a diameter of 0.8 mm has a better detonation performance and a higher pressure gain performance than the other one. High-speed images show the wall surface roughness affects the RDW strength greatly.

An experimental study on a flow control device applicable in pressurized networks

The flow control valve is able to deliver an almost constant discharge which is irrespective to the pressure fluctuations in a pressurized network. In this paper the design of a flow control device for incompressible flow is studied. The design criteria of the device are extended for wider discharge values up to Q = 0.6 l/s and differential pressure limits up to Δp = 20 m. In this regard, experiments were performed on cylindrical orifice device to obtain the associated discharge formula, based on which, the initial valve design was obtained. Then, the performance of the flow control device was enhanced according to analyzing the experimental results of the initial design and modifying the float shape line. A step-by-step design framework was then proposed based on which the improved design criteria were achieved for the design discharges of Q = 0.4 l/s with 1≤Δp (m)≤7, Q = 0.6 l/s with 1≤Δp (m)≤7, and Q = 0.6 l/s with 2.6≤Δp (m)≤20. According to the experimental results, average discharge values of 0.391 l/s, 0.625 l/s, and 0.568 l/s, with the associated relative errors of 2.2%, 4.2%, and −5.3% were obtained in comparison with the design values.

A hollow combustor that intensifies rotating detonation

Annular combustors are traditional, while hollow combustors without centerbodies are becoming popular for rotating detonation engines. Both schemes are studied experimentally in this paper to determine which combustor demonstrates a better detonation performance and pressure gain performance. The hydrogen and air sources are at room temperatures of 280–285 K. The annular and hollow combustors have the same scheme, although the centerbody is removed from the hollow combustor. The combustors are made optically accessible by embedding a piece of quartz glass in the outerbody. The hollow combustor channel has an outer diameter of 100 mm, and the detonation channel of the annular combustor has an inner diameter of 60 mm. Fuel and air are injected into the combustor from 150 cylindrical orifices with a diameter of 0.8 mm and a circular channel with a throat width of 1 mm, respectively. The results show that the hollow combustor demonstrates a better detonation performance and a higher pressure gain than the annular combustor. High-speed images show the rotating detonation is propagating with a lap time which is in good agreement with that obtained from pressure traces.

The effect of cavitation on the estimation of fuel injection rates based on momentum flux measurements

A study was conducted to determine how geometry-induced cavitation affects the reliability of injection rate estimates based on momentum flux measurements. Experiments were performed with two hydro-grinding diesel injector nozzles (Do = 190 µm), one having a cylindrical nozzle orifice that has a strong tendency to induce cavitation, and the other having a convergent nozzle orifice that tends to suppress cavitation. In addition, near-field microscopic images were captured to investigate the influence of cavitation on the liquid jet at the nozzle exit. The momentum flux measurements and near-field imaging were conducted at ambient pressure, using injection pressures of up to 2500 bar. When estimating the injection rate based on momentum flux measurements, failure to account for cavitation caused the integrated injection rate to be overestimated around 9% for the cavitating (cylindrical) nozzle but not for the non-cavitating (convergent) nozzle. We therefore recommend that cavitation should be accounted for when estimating injection rates for cavitating nozzles but not for non-cavitating nozzles. Further, we show that the tendency of a given nozzle orifice to induce cavitation can be evaluated by measuring the nozzle’s momentum flux under the assumption of zero cavitation and then comparing the estimated mass of injected fuel to the weighed mass.