Chamber Width Research Articles

Analysis of oblique wave interaction with perforated caisson breakwaters with partial wave absorption parts

This article presents a three-dimensional (3D) iterative analytical solution for water wave interactions with perforated caisson breakwaters with partial wave absorption parts based on linear potential flow theory. A periodic boundary condition is adopted for developing the series solutions of the velocity potentials by the separation of variables method. A quadratic pressure drop condition is imposed on the perforated walls to introduce wave energy dissipation. The unknown expansion coefficients in the velocity potentials are determined by matching the boundary conditions between adjacent fluid domains combined with iterative calculations. The hydrodynamic quantities, including the reflection coefficient, wave forces, and free surface elevation, are estimated. The convergences of the series solutions and the iterative calculation process are examined. The analytical solution calculations agree well with the known analytical and experimental results for special cases in the literature. Variations in the hydrodynamic quantities versus the main influencing factors are clarified. Partial wave absorption concept design enables the hydrodynamic performance of the present caisson breakwater with a smaller perforated wall area to be similar to that of a fully perforated caisson breakwater. To achieve a lower reflection coefficient and wave forces, the ratio of the wave chamber length to the caisson length is suggested to be 0.3–0.5, and the front wave chamber width should be less than half of the total wave chamber width.

The Effect of Parameter Variation on Spiral Flow Inducing Cannula Performances

Spiral flow-inducing cannula has been shown in previous research to exhibit a considerable effect on flow hemodynamic. However, there is still room for improvement. In this study, several design variations were tested to determine which variants were the best in terms of flow reduction. Computational Fluid Dynamics (CFD) software was used to simulate flow within a spiral flow-inducing cannula with several variations from chamber width and angle differences. The variants were compared against each other by using several flow parameters and a selection method was employed to determine which model was the best. It was found that a variant that has the widest chamber (14 mm) and biggest angle opening (70°) from the chamber to the cannula tube was the best in several parameters, and as such was chosen as the best variant. When compared with the standard straight cannula, the reduction in flow output was recorded to be 30% which is deemed significantly. In conclusion, spiral flow cannula recorded better hemodynamic effects with lower outflow velocity and wall shear stress value.

Numerical investigation on the performance of transcritical CO2 two-phase ejector with a novel non-equilibrium CFD model

Flashing flow in the transcritical CO2 ejector was simulated using a novel non-equilibrium evaporation-cavitation CFD model. The novel model was verified using the experimental results of three ejectors with nozzle diverging angles (NDAs) of 0°, 2.00° and 6.70°. Furthermore, the effects of dimensions of mixing chamber and diffuser on the ejector performance were disclosed. The results suggested that prediction errors of secondary flow mass flow rate using the proposed model were less than 9%, and the maximum error of primary flow mass flow rate was within the range of 15%, which was much smaller than that of −34.55% predicted by homogenous equilibrium model. The results also showed that the mass transfer rates increased with increasing NDAs, and the maximum mass transfer rate of evaporation was approximately 3–13 times that of cavitation as the NDAs increased from 0° to 6.70°, proving evaporation dominates the flashing process in the CO2 ejector. Besides, the results showed that the entrainment ratio increased first and then decreased with increasing the mixing chamber width, mixing chamber length and diffuser angle, and the entrainment ratio was improved by 36.55%. This study is helpful to understand flashing mechanisms inside the CO2 ejector and improve the ejector performance.

Intra-session repeatability of anterior chamber depth across the chamber width using Pentacam Scheimpflug imaging in healthy subjects.

Despite the importance of anterior chamber depth (ACD) measurements in disease and ageing, the repeatability and their threshold for change is not known. Our purpose was to determine the intra-session repeatability of Pentacam Scheimpflug photography for measuring the ACD across the chamber width in healthy subjects and thus inform expected limits of normality. Pentacam Scheimpflug photography was used to obtain ACD measurements at 57 points across the central 8mm of the chamber width from one randomly selected eye of 130healthy (normal vision and no ocular diseases, except age-normal cataracts) subjects (median age 58.0years, interquartile range 46.3-63.0years; 48males, 82 females). Intra-session ACD measurements were compared. Univariate and multivariate linear regression was performed to identify categorical and continuous variables demonstrating a significant relationship with ACD and its repeatability. Bland-Altman analyses showed no directional or depth-dependent bias in the difference between the first and second tests (mean bias -0.003mm, 95% limits of agreement -0.115 to +0.109mm). Multivariate analysis found gender to be a significant factor (p<0.0001), but not age (p=0.69) nor ethnicity (p=0.65), although the model fit was poor (R2 =0.004). There were no regional differences in repeatability measures found in males, but six locations in the superior aspect in females were found to be significantly different in their repeatability characteristics. Tolerance limits used to calculate the number of step sizes between <20 and >60-year-old age groups found 8.1-11.5steps for females, and 7.5-9.2steps for males. Scheimpflug imaging using the Pentacam has excellent intra-session repeatability. Only gender appeared to affect repeatability characteristics, manifesting with a greater number of meaningful steps of change between two extremes of age range in females compared to males, which provides guidance for identifying clinically significant and measurable change between tests.

Influence of Chamber Geometrical Parameters on Suppressing Explosion Propagation

In this article, the effect of a chamber’s geometrical parameters on suppressing gas explosion propagation was studied. Three rectangular chambers were used in the study, with a constant length of 0.5 m, a constant height of 0.2 m, and a variable width of 0.3 m, 0.5 m, and 0.8 m; each chamber was installed in a pipeline system for experimental research. The experimental results showed that when the chamber length and height were fixed at 0.5 m and 0.2 m, respectively, the suppression effect of the chamber on the explosion shockwave improves with the increase in the chamber width; when the chamber width increases to 0.8 m, the chamber has suppressive effect on explosion shockwave propagation. It was also found that the suppression effect of the chambers on the explosion flame improves with the increase in the chamber width; when the width of the chamber is 0.5 m, the chamber effectively suppresses explosion flames. Based on the experimental results, a numerical model was established to simulate the suppression effect of five types of chambers with a length, width, and height of 0.5 m × 0.3 m × 0.2 m, 0.3 m × 0.5 m × 0.2 m, 0.5 m × 0.5 m × 0.2 m, 0.5 m × 0.8 m × 0.2 m, and 0.8 m × 0.5 m × 0.2 m, respectively. The numerical simulation results indicated that when the chamber length and height are constant at 0.5 m and 0.2 m, respectively, the suppressive effect of the chamber on the shockwave improves as the chamber width increases; when the chamber width increases to 0.8 m, the shockwave overpressure at the chamber outlet is attenuated by 10.61%, indicating that the chamber suppresses the propagation of explosion shockwave, which is consistent with the experimental results obtained in the study. It was also found that when the chamber width and height were constant at 0.5 m and 0.2 m, respectively, as the chamber length increases, the overpressure increases first and then weakens. When the chamber length increases to 0.8 m, the overpressure at the chamber outlet is attenuated by −14.16%, indicating that the chamber is not able to suppress the propagation of explosion shockwave. Finally, a numerical simulation of the propagation process of a methane-air mixture and explosion flames in different chambers was performed to analyse the effect of chamber geometrical parameters on explosion suppression effect.

Numerical study of water waves interacting with open comb-type caisson breakwaters

The waves interacting with open comb-type caisson breakwaters was numerically investigated based on a three-dimensional numerical model by compiling a modified k-ω turbulence model. The numerical model can significantly supress nonphysical overestimation of turbulence kinetic energy. The numerical model was established in a specific strip of breakwater by introducing a periodic boundary condition to improve computational efficiency. The numerical model was validated against analytical and experimental results. Effects of wave and structural parameters on hydrodynamic performances, including wave reflection, wave transmission, wave forces, and energy dissipation, were investigated. The numerical results suggested the significance of the relative chamber width on hydrodynamic quantities. The hydrodynamic interaction, including the wave run-up on the superstructure and the eddy formation process, was illustrated by the time instants of the velocity and dynamic pressure, turbulence kinetic energy field and streamline. The energy dissipation was mainly due to wave breaking and vortex shedding and hence effectively reduced the wave transmission but had little influence on wave reflection. More wave energy went to higher frequency component as incident wave period increased. The investigation regarding the phase shift of wave forces acting on rectangular caisson and the side plates proved the advantage in mechanical characteristics of comb-type structure.

Association of peripheral anterior synechiae with anterior segment parameters in eyes with primary angle closure glaucoma

To investigate the association of peripheral anterior synechiae (PAS) with intraocular pressure (IOP) and anterior-segment parameters in subjects with primary angle-closure glaucoma (PACG). A total of 267 subjects with PACG were recruited and underwent gonioscopy and anterior-segment optical coherence tomography (ASOCT). Customized software was used to measure ASOCT parameters, including angle opening distance (AOD750) and trabecular-iris-space-area (TISA750) at 750 µm from the scleral spur, anterior chamber depth, width, area and volume (ACD, ACW, ACA, ACV), iris thickness (IT750), iris area (IAREA), and lens vault (LV). Presenting IOP was defined as the first IOP reading before the initiation of IOP-lowering treatment. The mean age of the 267 subjects was 67.0 ± 8.9 years, 140 (52.4%) were male, and 246 (92.1%) were of Chinese ethnicity. PAS was present in 122 (45.7%) subjects, and was most frequently found in the superior quadrant (79.5%). Subjects with PAS had greater presenting IOP (28.7 ± 12.9 vs 22.4 ± 9.7 mmHg, p < 0.001), narrower AOD750 (p < 0.001), smaller TISA750 (p < 0.001), ACD (p = 0.04), ACA (p = 0.02), ACV (p = 0.01) and larger LV (p = 0.01) compared to PACG eyes without PAS. No significant differences were noted for iris parameters. A multivariate logistic regression analysis showed that higher presenting IOP (β = 0.20, p < 0.001), worse visual field mean deviation (β = − 0.20, p = 0.01) and narrower AOD750 (β = − 0.25, p = 0.03) were the only parameters that significantly correlated with the extent of PAS in clock hours. Almost one-half of the subjects with PACG demonstrated PAS; these eyes were associated with higher presenting IOP, smaller anterior segment dimensions and more severe disease.

Diagnostic accuracy of swept source optical coherence tomography classification algorithms for detection of gonioscopic angle closure

PurposeTo evaluate the performance of swept source optical coherence tomography (SS-OCT) to detect gonioscopic angle closure using different classification algorithms.MethodsThis was a cross-sectional study of 2028 subjects without ophthalmic symptoms...

Compensation scheme for non-linear beam defocusing inside planar undulator

The Delhi Light Source (DLS), is a compact THz facility based on the principle of pre-bunched FEL, which is at the commissioning stage at Inter University Accelerator Centre (IUAC), New Delhi. The facility will produce relativistic electron beam in the energy range 4 to 8 MeV to generate THz radiation in the range 0.18–3.0 THz. To study the effect of the undulator U48 on this low energy range of the electron beam, a 3D field map of U48 was generated with the help of measured magnetic field data. Beam tracking simulations were performed with the generated field map at the minimum gap of U48. Simulations showed that the quadrupole component of the transverse field roll-off, which is the dominant component within the width of the vacuum chamber can introduce a substantial growth of the beam size in the wiggling plane and result in severe beam loss while propagating through the vacuum chamber inside the undulator. To compensate the dynamic quadrupolar field, an extended quadrupole field correction coil was implemented in the simulation by superimposing its field on the magnetic field of U48. Such a correction scheme showed a remarkable improvement to contain the beam transverse growth.

Displacement between anterior chamber width obtained by swept-source anterior segment optical coherence tomography and white-to-white distance.

PurposeTo determine the relationship between the external limbal location, represented by white-to-white (WTW) distance, and the actual angle location, represented by spur-to-spur (STS) and angle-to-angle (ATA) distances.Methods166 eyes from 166 participants were imaged using CASIA2 anterior chamber optical coherence tomography (AS-OCT) and LenStar LS 900 optical biometer. The horizontal ATA and STS were measured using the swept-source Fourier-domain AS-OCT (CASIA2). The horizontal WTW was automatically measured using LenStar. The displacement lengths (DL) between WTW-STS and WTW-ATA were calculated. Bland-Altman plots and intraclass correlation were performed.ResultsThe study showed that WTW has a positive correlation with STS (ICC = 0.82, p<0.001) and ATA (ICC = 0.82, p<0.001). The Bland-Altman analysis demonstrated that the mean difference of WTW-STS is 0.10 mm (95% CI 0.06 to 0.14 mm) with limits of agreement of -0.42 to 0.63 mm between WTW and STS, and the mean difference of WTW-ATA is 0.10 mm (95% CI 0.06 to 0.15 mm) with limits of agreement of -0.48 to 0.64 mm between WTW and ATA. Linear regression with adjustment showed that a WTW value greater than 12.07 mm is associated with a greater DL (WTW-STS DL ß 0.18, p = 0.003; WTW-ATA DL ß 0.14, p = 0.03).ConclusionsGreater WTW was significantly associated with higher displacement of WTW from the two distances representing anterior chamber width. External limbal location may not accurately represent the actual angle location in eyes with larger WTW.

Anterior Chamber Measurements in Healthy Children: A Cross-Sectional Study Using Optical Coherence Tomography.

PurposeTo establish anterior chamber measurements in children and investigate the influence of demographic factors on anterior chamber development.MethodsHandheld optical coherence tomography was used to scan the anterior chamber of participants’ eyes, without sedation. ImageJ was used to generate quantitative anterior chamber measurements, including central corneal thickness (CCT), anterior chamber width, trabecular meshwork length (TML), Schwalbe's line–angle opening distance (SL-AOD), and trabecular iris surface area (SL-TISA). The average anterior chamber measurements per age group, with 95% prediction intervals, were estimated using fractional polynomial modeling. Mixed regression models were used to evaluate the influence of age, gender, eye, angle, and refractive error variation on anterior chamber measurements.ResultsScans from 223 healthy children (2 days to 15 years of age) and 59 adults (16 to 47 years of age) were included. The anterior chamber width, TML, Schwalbe's line–angle opening distance, and Schwalbe's line–trabecular iris surface area significantly increased, whereas CCT decreased with aging (all P < 0.001). The anterior chamber has a rapid phase of development during the first 18 months of age and reaches maturity by the age of 5 years. Girls have significantly smaller anterior chambers compared with boys (all P < 0.001). There was no difference between right and left eye development (all P > 0.05). The temporal TML development was significantly greater than the nasal TML (P < 0.05). CCT development was negatively correlated with refractive power.ConclusionsThis novel, non-invasive study describes the postnatal development of anterior chamber in newborn children.Translational RelevanceOur established quantitative measurements have potential clinical use in understanding anterior segment diseases.

Performance of an OWC device placed over multi-stepped bottom in random waves environment

The performance of an OWC device placed over multi-stepped bottom is analyzed in random incident waves environment. To model the irregular local wave climate, the Pierson-Moskowitz spectrum along with two different sea states are considered. The effect of chamber width, lip-wall thickness and draft, and turbine damping coefficient of the OWC device on the performance and efficiency are discussed in a detailed manner. It is observed that the OWC device parameters and the local wave climate play a crucial role on the performance and efficiency of the OWC device.

A correlation study of optimal chamber width with the relative front wall draught of onshore OWC device

Based on the open source OpenFOAM software package, a computational fluid dynamic model for two-phase incompressible flow (air and water) is developed to study the correlation of the optimal chamber width with the relative front wall draught of the onshore Oscillating Water Column (OWC) device. The numerical model is firstly validated by comprising the predicted results with the corresponding experimental data for wave interaction with the fixed offshore and onshore OWC devices with different opening ratios. The validated model is applied to study the influence of the front wall draught and the chamber width on the wave energy conversion efficiency of the onshore OWC device. Phase differences of the water surface fluctuations inside and outside the chamber are discussed. Based on the numerical results, an exponential fitting formula is proposed to describe the correlation between the optimal relative chamber width and the relative front wall draught, and wavelength is also included in the fitting formula to consider the effect of wave conditions. Good agreements are found between the predicted results by the proposed fitted formula and the existing data in the literatures related to the onshore OWC device with different opening rates and wave conditions.

Evaluation of 3-D Computational Model of Oscillating Water Column Converter with Constructal Design with Three Degrees of Freedom and Limited Chimney Height

Theoretically, ocean waves contain enough mechanical energy to supply the entire world’s demand and, as of late, are seen as a promising source of renewable energy. To this end, several different technologies of Wave Energy Converters (WEC) have been developed such as Oscillating Water Column (OWC) devices. OWCs are characterized by a chamber in which water oscillates inside and out in a movement similar to that of a piston. This movement directs air to a chimney where a turbine is attached to convert mechanical energy. The analysis conducted was based on the Constructive Design Method, in which a numerical study was carried out to obtain the geometric configuration that maximized the conversion of wave energy into mechanical energy. Three degrees of freedom were used: the ratio of height to length of the hydropneumatic chamber (H1/L), the ratio of the height of the chimney to its diameter (H2/d) and the ratio of the width of the hydropneumatic chamber to the width of the wave tank (W/Z). A Design of Experiments (DoE) technique coupled with Central Composite Design (CCD) allowed the simulation of different combinations of degrees of freedom. This allowed the construction of Response Surfaces and correlations for the efficiency of the system depending on the degrees of freedom (width and height of the chamber), as well as the optimization of the system based on the Response Surfaces.

Agreement of Ocular Biometry Measured by LenStar LS 900 and CASIA2 Optical Coherence Tomography

Introduction:The present study aimed to compare the anterior segment measurements between optical low-coherence reflectometry (LenStar LS900) and anterior segment optical coherence tomography (CASIA2 OCT). Methods:A total of 198 right eyes of 198 healthy participants were used for the current study, according to the inclusion and exclusion criteria. Ocular biometry parameters, such as central corneal thickness (CCT), anterior chamber depth (ACD), keratometry, and anterior chamber width (ACW), were measured usingLenStar LS 900 and CASIA2 OCT. The differences and correlations were assessed between these two instruments. The agreement was calculated as the 95% limits of agreement (LoA). Results: Among 198 subjects with a mean age of 29.39±7.88 years who enrolled in the study, 106 individuals (53.5%) were women. The mean CCT values were 531.7±35.25 and 527.3±37.82 µm for LenStar and OCT, respectively (P˂0.0001). The ACD measurements showed 2.92±0.40 and 2.95±0.43 mm for LenStar and OCT, respectively (P=0.0549). The ACW mean values were 12.04±0.52 and 11.79±0.49 mm by LenStar and OCT (P˂0.0001). The 95% LoA between the two instruments were within the ranges of -20.79 to 29.43 µm, -0.50 to -0.43 mm, -0.32 to 0.82 mm, and -0.70 to 0.87 D for CCT, ACD, ACW, and astigmatism, respectively. Conclusion: LenStar and OCT showed to have interchangeable ACD measurements; however, the results of CCT, ACW, and corneal astigmatism measured by these two instruments demonstrated clinically significant differences

Changes in anterior segment optical coherence tomography following pars plana vitrectomy without tamponade

BackgroundTo evaluate changes in anterior segment morphology on anterior segment optical coherence tomography (AS-OCT) following pars plana vitrectomy (PPV) without tamponade.MethodsPatients who underwent PPV without tamponade for epiretinal membrane were evaluated. Eligible patients underwent intraocular pressure (IOP) measurement and AS-OCT preoperatively as well as 1 month and 6 months post-operatively. Anterior chamber width (ACW), anterior chamber depth (ACD), trabecular iris angle (TIA), angle opening distance at 500 and 750 µm (AOD), and trabecular iris space area at 500 and 750 µm (TISA) at four quadrants were recorded and analyzed. Additionally, the mean values of TIA (MTIA), AOD (MAOD), and TISA (MTISA) for each eye (mean of four quadrants) were analyzed.Results23 patients completed the study. The mean age of participants was 56.4 ± 3.6 years of age and 13/23 (56%) were female. Mean IOP of patients was 18.1 ± 1.1, 18.3 ± 1.1, and 18.1 ± 1.2 preoperatively,1 month post-operatively, and 6 months post-operatively, respectively. (p = 0.83). No difference was detected post-operatively in measurements of ACW, ACD, MTIA, MAOD500, MAOD750, MTISA500, and MTISA750.ConclusionPars plana vitrectomy without tamponade was not associated with changes in anterior chamber morphology.

Influence of Wave-Absorbing Chamber Width on the Wave Attenuation Performance of Perforated Caisson Sitting on Rubble-Mound Foundation

A Jarlan-type perforated caisson consisted of a perforated front wall, a solid rear wall, and a wave-absorbing chamber between them. The wave-absorbing chamber was the main feature of the perforated caisson, and its width had a great effect on wave attenuation performance. In this study, a larger range of the wave-absorbing chamber width was observed in model experiments to investigate the effect on wave attenuation performance including the reflection coefficients and the horizontal wave forces of a perforated caisson sitting on a rubble-mound foundation. A resistance-type porosity numerical model based on the volume-averaged Reynolds-averaged Navier–Stokes (VARANS) equations was validated by comparing the present results with those of previously reported and present experiments. The validated numerical model was then used for extended research. It was found that the reflection coefficients, the total horizontal wave force, and its components all tended to oscillate in a decrease ⟶ increase ⟶ decrease manner with increasing the wave-absorbing chamber width. The reflection coefficients and wave forces acting on both sides of the perforated front wall were found to be synchronized regardless of perforation ratio or the rubble-mound foundation height.

The Iris Thickness in a Healthy Saudi Population.

PurposeIris thickness (IT), a known risk factor for angle closure glaucoma, has not been evaluated in the normal Saudi population.MethodsQuantitative information on IT was evaluated in healthy Saudi eyes using anterior segment optical coherence tomography (ASOCT). IT and iris volume was measured with the room ‘light on’ (LON) and ‘light off’ (LOFF) using Image J software. IT in the nasal and temporal iris was measured at 500 µm (IT500) and 750 µm (IT750) from the scleral spur (SS). Differences in IT measurements by age, gender and type of refractive error were evaluated.ResultsWe included 100 eyes of 50 healthy adult Saudis without ocular disease other than refractive errors. The mean age of 56 males and 44 females in the study group was 41.7 ± 14.5 years. The refractive status was as follows: emmetropia (35 eyes), mild/moderate myopia (33 eyes), high myopia (17 eyes) and hyperopia (15 eyes). The IT750 with LON was significantly more than IT500 both nasally (P = 0.03) and temporally (P < 0.001). The difference in IT750 and IT500 with LOFF was significantly more nasally (P = 0.03), temporally (P = 0.02), and with LON nasally (P = 0.005). IT was thicker in males when compared to females and variation of IT by refractive error was significant but not by age. The mean pupil diameter and anterior chamber depth decreased with age (P < 0.001). Anterior chamber width was not affected by age or illumination.ConclusionThe baseline iris thickness in the Saudi eyes could be used to compare iris thickness in eyes with angle closure glaucoma among the Arab population.

Hydrodynamic Performance of Wave Interaction with Curtain-Wall Breakwater: Using the MPS Model

Iddy, I.; Jiang, Q., and Zhang, C., 2020. Hydrodynamic performance of wave interaction with curtain-wall breakwater: Using the MPS model. In: Hu, C. and Cai, M. (eds.), Geo-informatics and Oceanography. Journal of Coastal Research, Special Issue No. 105, pp. 76–80. Coconut Creek (Florida), ISSN 0749-0208.This paper examines the hydrodynamic performance of wave interactions with double curtain-wall breakwater by the laboratory experiment and numerical model. A vertical two-dimensional moving particle semi-implicit (MPS) numerical model is developed and verified by comparison of the simulated and experimental results. Then it is applied to investigate wave interaction with partially immersed double curtain walls at different immersion depths, porosity of perforated front wall, and chamber width. A good agreement is shown between the numerical results and the experimental data, indicating that the proposed MPS numerical model can successfully capture the essential aspects of wave interactions with breakwater structure and can be a useful predictive tool.

Relationship between Axial Width and Flow Characteristics of Pump Chamber in Double Volute Centrifugal Pump

The axial width of pump chamber has a great influence on the flow characteristics of the pump chamber in the centrifugal pump. A single-stage single-suction double volute centrifugal pump with a semi-open impeller was selected as the object. For the 6 different pump chamber axial width, it was concluded that the pump chamber pressure at the different angles (0°, 90°, 180°, 270°) along the radial variation characteristics according to the contrast analysis of the pump cavity pressure field, velocity field distribution. The correlation between the pump chamber pressure and the impeller radius was revealed. The tangential velocity and radial velocity along the axial distribution curves were draw. The results show that when the axial width of pump chamber increases from 23.9 mm to 43.9 mm, the pressure value of the same radial position increases gradually. The radial pressure difference is decreasing. At the same axial width of pump chamber, the pressure mean increases along the radial approximately parabola. The tangential velocity of different angular directions has little difference in axial distribution. The mean of dimensionless tangential velocity in the turbulent core area decreases from 0.32 to 0.19 with the increasing of pump chamber axial width. The radial velocity varies is greatly along the axial direction. There are eddies at the directions of 0ånd 180°, but the mean of radial velocity in the turbulent core area is about 0. This research provides the reference for centrifugal pump hydraulic design, structural design and the accurate calculation of axial force.