Maximum Flow Research Articles

Can We Differentiate Between Organic and Functional Bladder Outlet Obstruction in Males With Parkinson's Disease?

To determine the type of bladder outlet obstruction (BOO) in patients with Parkinson's disease (PD). A case-control study was carried out in 46 patients divided into two groups. Group 1 formed by 23 PD patients with BOO (a URA parameter ≥ 29 cm H2O). Group 2 formed by 23 patients with benign prostatic hyperplasia (BPH) and compressive obstruction (an opening pressure > 35 cm H2O) and URA parameter ≥ 29 cm H2O). Both groups underwent a pressure-flow study to calculate Dynamic Urethral Resistance Relationship (DURR) patterns. Based on previous research, we describe two types of DURR pattern. Pattern A typical of dynamic or functional obstruction and pattern B typical of static or organic obstruction. We found that PD patients had a significantly higher frequency of pattern A (70%) than BPH patients (4%). Other significant differences between groups were age (greater in PD group), bladder compliance (greater in PD group), maximum flow rate [Qmax (greater in BPH group)], maximum detrusor pressure [Pmax (greater in BPH group)], detrusor pressure at maximum flow rate [PQmax (greater in BPH group)], opening detrusor pressure (greater in BPH group), and the bladder contractility parameters BCI and Wmax (greater in BPH group). There were no significant differences in perineal voiding electromyography (EMG) activity between groups nor relationship between voiding EMG activity and the type of DURR pattern. Our results are consistent with the usefulness of the DURR pattern to differentiate between functional and organic BOO in PD patients. Most PD patients have functional obstruction although a minority has organic obstruction consistent with BPH.

The Effect of Physiotherapy on Erectile Dysfunction Secondary to Prostatic Adenectomy: A Randomized Control Trial Study.

The objective of this randomized controlled trial was to investigate the impact of manual therapy (friction massage) and pelvic floor muscle (PFM) training on erectile dysfunction (ED), pelvic floor muscle thickness, and blood flow in the penile arteries and veins in men who have undergone prostatic adenectomy (PA). This study employed a randomized, double-blinded, controlled trial design. Forty patients participated and were divided into two groups: intervention and control (n=20 per group). The intervention group received 10 sessions of pelvic floor muscle training and manual therapy, while the control group solely underwent pelvic floor muscle training. The recovery rate was measured using the International Index of Erectile Function 15 (IIEF-15) questionnaire and Erection Hardness Score (EHS). Sonographic factors were assessed using simple and Doppler ultrasound. The intervention group exhibited significantly higher erectile function scores (F(1,37)=158.04, P < 0.001, η2 P = 0.810) and a higher average total (IIEF-15) score (20.52) (F(1,37)=136.76, P < 0.001, η2 P = 0.787) compared to the control group in the post-test assessment. Comparison between the two groups revealed an increase in ultrasonic parameters such as the thickness of the ischiocavernosus and bulbospongiosus muscles, maximum systolic velocity, and minimum diastolic velocity of the cavernosal artery in the intervention group. However, the maximum blood flow velocity in the posterior vein decreased. PFM training and friction massage play a significant role in managing ED following PA, positioning them as the primary treatment approach for men experiencing ED post-prostatectomy.

A piezoelectric pump with composite vibrator for bubble resistance

Piezoelectric pumps, as microfluidic drive units, are widely used in microfluidic systems. Due to the fact that most piezoelectric pumps are driven by displacement, the introduction of air bubbles will produce a significant impact on their output performance. To minimize the adverse effect of air bubbles, a piezoelectric pump with composite vibrator (PPCV) is proposed. The composite vibrator consists of the active vibrator and the passive vibrator. By vibrating the passive vibrator in the pump chamber, it prevents bubbles retention. Multi-physics field simulation is established，which verifies the PPCV is feasible. Furthermore, a prototype is fabricated and experimentally investigated. At a voltage of 300 Vpp, the experimental results indicate a maximum output flow rate of 41.4 ml/min and a maximum output pressure of 18.7 kPa. After continuously entering 100 bubbles, the output performance of the PPCV decreases by less than 10 %, indicating that the PPCV owns excellent bubble resistance ability. The PPCV provides a new approach to microfluidic pumping devices.

Exact closed-form solution for buckling and free vibration of pipes conveying fluid with intermediate elastic supports

In this paper, the exact closed-form solution is given to investigate the influence of the intermediate elastic support on the buckling and free vibration of an elastically supported pipe. According to the Euler–Bernoulli beam theory, the mechanical model of the pipe is established. The exact equilibrium configuration is derived using the generalised function method without enforcing continuity conditions. A simple solution to the eigenvalue problem is formulated using the methods of complex mode superposition and Laplace transformation. The comparative study shows the differences in the supercritical vibration characteristics and highlights the limitations of previous studies. Parametric studies are carried out to investigate the influence of elastic support and intermediate support conditions on the equilibrium configuration, critical flow velocity, and natural frequency. The results demonstrate that the proposed closed-form solution can determine the support conditions that lead to the maximum critical flow velocity and natural frequency of a pipe with multiple intermediate supports. The maximum values are required to adjust the support conditions leading to the nodes of higher-order equilibrium configurations and complex modes. Furthermore, the natural frequencies of the pipe conveying supercritical fluid no longer satisfy the monotonicity for the support stiffness, the symmetry for the support position, and the ‘zero-point’ property for the support number.

HYDROLOGICAL REGIME AND WATER RESOURCES OF RIVERS OF THE ZERAFSHAN BASIN UNDER CLIMATE CHANGE

The work assessed the impact of climate change on the hydrological regime - long-term fluctuations, intra-annual distributions, maximum flow rates and, in general, on the water resources of the rivers of the Zeravshan basin. Calculations to assess changes in meteorological parameters were performed for two climatic periods. Some changes in the regime of air temperature and precipitation were revealed. Their influence on the hydrological regime of rivers is assessed. Particular attention is paid to the issues of quantitative assessment of water resources of the rivers of the studied basin.

Lentinan combined with docetaxel and nedaplatin in the treatment of pulmonary tuberculosis complicated by nonsmall cell lung cancer

Purpose: To investigate the efficacy and safety of lentinan combined with docetaxel and nedaplatin (DN) in the treatment of pulmonary tuberculosis complicated by non-small cell lung cancer (NSCLC). Methods: A total of 100 patients diagnosed with pulmonary tuberculosis combined with NSCLC in Ankang People's Hospital, Ankang, China were randomized equally into study and control groups. Control group received standard anti-tuberculosis therapy and intravenous chemotherapy regimen based on docetaxel (75 mg/m² on day 1) and nedaplatin (80 – 100 mg/m²), while the study group received, in addition, lentinan (given intravenously every two days). The patients received a total of 2 courses of treatment. Tumor response, survival, adverse reactions, quality of life score, and pulmonary function indices were compared before and after treatment. Results: The study group showed significantly higher total response rate than the control group (p &lt; 0.05). Median overall survival and progression-free survival in the study group was significantly higher than in the control group (p &lt; 0.05). Also, the study group showed significantly lower incidence of adverse reactions compared to control group (p &lt; 0.05). Quality of life score, maximum voluntary ventilation (MVV) and peak expiratory flow (PEF) levels in the study group was significantly higher compared to control group (p &lt; 0.05). Conclusion: Lentinan combination with DN chemotherapy regimen improves response rate, prolongs survival, reduces incidence of adverse reactions, improves quality of life and pulmonary function in patients with pulmonary tuberculosis complicated by NSCLC. These findings provide a new perspective for future studies on the application of lentinan in the treatment of pulmonary tuberculosis complicated by NSCLC.

Sensitivity of flows over three-dimensional swept wings at low Reynolds number

High angle of attack flows over swept three-dimensional wings based on the NACA 0015 profile are studied numerically at low Reynolds numbers. Linear stability analysis is used to compute instability and receptivity of the flow via the respective three-dimensional (triglobal) direct and adjoint eigenmodes. The magnitude of the adjoint eigenvectors is used to identify regions of maximum flow receptivity to momentum forcing. It is found that such regions are located above the primary three-dimensional separation line, their spanwise position varying with wing sweep. The wavemaker region corresponding to the leading global eigenmode is computed and found to lie inside the laminar separation bubble (LSB) at the spanwise location of peak recirculation. Increasing the Reynolds number leads to the wavemaker becoming more compact in the spanwise direction, and concentrated in the top and bottom shear layers of the LSB. As sweep is introduced, the wavemaker moves towards the wing tip, following the spanwise displacement of maximum recirculation. Flow modifications resulting from application of different types of forcing are studied by direct numerical simulation initialised with insights gained from stability analysis. Periodic forcing at the regions of maximum receptivity to momentum forcing results in greater departure from the baseline case compared to same (low, linear) amplitude forcing applied elsewhere, underlining the potential of linear stability analysis to identify optimal regions for actuator positioning.

A three-dimensional curve interface reconstruction algorithm for two-phase fluid flow

The curve interface reconstruction algorithm has received significant attention in the context of two-dimensional two-phase flow. However, it remains absent in the three-dimensional scenario. This paper proposes a novel three-dimensional curve interface reconstruction (CIR) algorithm to address this challenge within structured meshes for the first time. Specifically, a portion of the spherical surface is employed to reconstruct the three-dimensional curve interface segment, with the radius and center coordinates determined by curvature and mass conservation constraints, respectively. To enhance curvature accuracy, a sphere-based iterative reconstruction (SIR) algorithm is proposed to calculate the reconstructed distance function (RDF) for the three-dimensional curve interface. Various tests involving the interface reconstruction of spherical, ellipsoidal, and cubic objects demonstrate that the coupled SIR and CIR (SIR-CIR, simplified by SCIR) method achieves higher accuracy than many popular methods, particularly with coarse mesh resolutions. Additionally, the SCIR method offers the advantages of straightforward implementation and coding for interface reconstruction in two-phase flow research. This advantage results in reduced computational costs compared to the coupled volume-of-fluid and level set (VOSET) method, which also utilizes an iterative method to solve RDF.

Design of experimental facility for helium gas component testing

The current state-of-the-art helium gas test loops for component testing are constrained by the maximum operating temperatures, pressures, and flow rates of such facilities. Idaho National Laboratory is designing a new experimental facility known as HECTOR (HElium Component Testing Out-of-pile Research), which is a helium gas test loop for evaluating the performance of components to helium gas pressures, temperatures, and flow rates up to 8 MPa, 800 °C, and 0.15 kg/s, respectively. The construction of this facility will enable researchers to perform experiments across a wide range of Reynolds and Nusselt numbers, which could result in the maturation of technology for high-temperature gas-cooled reactor (HTGR) components.

An integrated distributionally robust model for two-echelon patient appointment scheduling

We develop a distributionally robust optimization (DRO) model for the outpatient appointment scheduling problem of a set of patients served in two serial stages, consultation and examination. The arrival sequence of patients is known, and the problem of scheduling is to assign appointment time for each patient to minimize total cost with random service time for two serial stages. A max–min problem is formulated for the two-stage appointment scheduling as a whole, in which the waiting time exhibits a high degree of coupling due to the continuous two-stage process. To address this, we devise a two-stage network maximum flow model that provides an equivalent linear expression for the waiting time. For the inner maximum problem, we employ a conic programming approach for equivalent representation, incorporate the scheduling decision of the outer minimum problem, and convert the model to its equivalent copositive programming by taking the conic duality. We conduct numerical experiments and sensitivity analysis using real and simulated data, and the results verify the effectiveness of our proposed DRO model.

Comparative analysis of macroscopic traffic models for evaluating shockwaves under lane closures on an urban highway using the LWR model

ABSTRACT Lane closure due to traffic crashes is a complex phenomenon that negatively affects the operational performance of highways and leads to secondary lane closures. The present study investigates the effects of shockwaves caused by a heavy vehicle run-off-road crash on a three-lane urban highway in Isfahan, Iran. Additionally, the study simulates the effects of lane closures on shockwaves and density using the Lighthill, Whitham, and Richards (LWR) theory and macroscopic traffic flow based on field data. An analysis of traffic flow models revealed that one-lane and two-lane closures reduce maximum flow by 29% and 61%, respectively, compared to normal conditions. The results showed that the minimum relative error (RE) for lane closures is associated with shockwave models based on the Underwood speed-density model, expanded using the Taylor series. Therefore, the shockwave model based on the Underwood model with Taylor series expansion outperforms other models.

An experimental study of transient front velocity for miscible exchange flow in a rectangular channel

ABSTRACT This experimental study considers the exchange flow of two miscible fluids in a rectangular channel. The main purpose is to understand the mixing dynamics and explore how mixing and different channel inclinations can affect variations in front velocity. In contrast to previous studies, no steady state is assumed. The larger channel cross-section used in the current study provides an opportunity to visualize and analyze the inertia dominated regime in finer details. For horizontal channels, after opening the gate valve and allowing the transient phase to pass, it is observed that the front velocity remains almost constant for a period before gradually decreasing. In inclined flows, the mixing and transition to inertia dominated flow begin when the viscous flow rate of the main flow increases. This flow rate may exceed the maximum flow rate that the front can tolerate according to the equations describing the momentum balance at the front. At sufficiently high density contrasts or large inclinations, the front velocity may continue to decrease as the flow progresses due to interfacial instabilities and mixing. Under such conditions, the results may also cast doubt on the presence of a true steady state front velocity in miscible exchange flow.

Hawaiian legends of coastal devastation and paleotsunami reconstruction, Nu'u, Kaupō, Maui, Hawai'i

In Hawaiʻi, tsunamis are often described in orally transmitted legends (moʻolelo). This study examines sedimentary evidence of a possible local submarine landslide-generated tsunami, described in a legend from the south east coast of Maui which originated between the 15th Century CE and the first arrival of Europeans in 1778 CE. Physical evidence for a tsunami, found at the Nu'u Refuge, Maui, is primarily comprised of an extensive coral clast deposit (found 8.5 m above msl and 251 m inland from the shoreline) together with waterworn cobbles which form fracture-embedded wedge clasts in a local basalt escarpment (at up to 8 m above msl). U/Th dating of the coral clasts gives a maximum tsunami deposit age of 1671 CE for the event that may have inspired the local moʻolelo. This depositional sequence is used to characterize the nature of the assumed tsunami in terms of inundation distance, maximum wave runup and minimum flow velocities. A numerical model developed using GeoClaw matches well with the physical evidence. The data and modeling presented here suggest that locally-generated tsunamis from submarine landslides warrant further research attention as sources of destructive high energy marine inundation events.

On-orbit spectral characteristics analysis of the greenhouse gases monitoring instrument: Spectral wavelength stability and instrumental line shape stability

The Greenhouse Gases Monitoring Instrument (GMI) is a carbon satellite payload developed based on the principle of spatial heterodyne spectroscopy technology, which is specifically designed for the global analysis of greenhouse gases (CO2 and CH4) “sources” and “sinks”. Due to the low concentration and minimal gradient variations of CO2 and CH4 in the atmosphere, higher precision is required for their retrieval. Vibrations during satellite launch and harsh space environments during on-orbit operation may cause changes in the performance of various payload components, resulting in decreased quality of spectrum products and retrieval precision. This paper proposes a set of on-orbit spectral characteristic evaluation methods tailored for the GMI to monitor the quality of its spectrum. It also develops an adaptive blind pixel detection and correction algorithm specifically for the GMI and optimizes the interferogram processing flow algorithm. On-orbit spectral calibration is performed, and methods to evaluate spectral characteristic parameters have been established. The analysis focuses on the variations of the spectral characteristics in the CO2-1 bands (1.575 μm) of the GMI during one-year of on-orbit calibration spectrum. The initial spectral wavenumber offset is 0.133 cm−1 after entering orbit, and the average spectral wavenumber offset is 0.0313 cm−1 during stable operation. During the one-year period, the maximum variation in the instrumental line shape function of the GMI is 0.006 cm−1. The observed spectrum obtained in nadir observation mode, underwent to accuracy verification. The results demonstrate consistency between the spectral peak wavenumbers and the relative trend changes of the observed and theoretical spectrum, with an average relative residual of 0.987%.

Comparison of the Role of Anticholinergics and α-1 Adrenergic Blockers in Bladder Management in Posterior Urethral Valves: A Pilot Randomized Control Trial

Introduction: Posterior urethral valve (PUV) is a major cause of congenital bladder dysfunction, often persisting despite treatment. Emerging therapies, including anticholinergics and α-1 blockers, offer potential but lack clear guidelines. This study evaluates their effectiveness in improving bladder function after valve fulguration. Methods: Twenty PUV patients, aged ≥3 years, were randomized into anticholinergic (group A, n = 11) and α-1 adrenergic blocker (group B, n = 9) groups post-fulguration. Follow-up included clinical, radiological, and urodynamic assessments 6 months posttreatment initiation. Results: In group A, the mean maximum detrusor pressure (Pdet) decreased from 30.17 to 23.45 cm H2O (p = 0.033). Two patients normalized from high detrusor pressure (>40 cm H2O). In group B, 1 patient retained high detrusor pressure posttreatment. Group B improved in average urinary flow (Q avg) and maximum flow rate (Q max), with all patients having initially low Q avg (<10 mL/s). Two group B patients showed improved average flow rates posttreatment (p = 0.016); three in group A showed improvement but were not statistically significant (p = 0.197). Q max/flow time ratio was abnormal in all group B patients pretreatment. Two of the nine improved posttreatment, while only one in group A did. Conclusions: Anticholinergic medications positively impact cystometric parameters and are effective for detrusor instability and low compliance bladder. α-Adrenergic blockers influence uroflow parameters and can help treat bladder outflow obstruction. Consideration for a larger study with extended follow-up is warranted.

Comprehensive pulmonary function analysis identifies predominant obstructive phenotype in former premature infants around one year of age.

Preterm infants suffer from significant respiratory morbidity during the first years of life, but the underlying lung pathophysiology is not fully understood. This study aimed to comprehensively characterize the pulmonary functions of preterm infants using full infant pulmonary function testing (iPFT). Between 2008 and 2019, we recruited 150 infants (Mage 10.5 ± 6 months) of them 104 preterm infants (median gestational age [GA] = 34 weeks (28-36), n = 23 with bronchopulmonary disease [BPD]) and 46 controls born at term. We compared full iPFT parameters of preterm infants to a control group of term infants. Subanalysis included a comparison of preterm infants by BPD status and GA. Preterm infants had impaired flow parameters, reduced compliance, and air trapping, compared to term infants. Only 15% (n = 14) of the preterm group had normal iPFT, compared to 69% (n = 31) of the term group. The majority of the impaired iPFT in preterm infants were obstructive and 72% (n = 69) had no response to bronchodilators. Reduced maximal flow at the functional residual capacity point (V'maxFRC) was associated with low birth weight and GA. There were no major differences between preterm infants with or without BPD. Preterm infants in the first year of life, demonstrated a high prevalence of obstructive iPFT unresponsive to bronchodilators. BPD status did not add to the degree of pulmonary impairment. These data reveal an airway-predominant pathology of the modern-era prematurity-associated lung disease. Pulmonary function screening tests at an early age may be of value in determining the presence and severity of lung disease in the preterm population. V'maxFRC may provide a good assessment of pulmonary impairment in preterm infants.

Observation-based quantification of aerosol transport using optical flow: A satellite perspective to characterize interregional transport of atmospheric pollution

Interregional transport plays a significant role in haze formation with varying and disputable contribution extent. Current research on quantitatively analyzing interregional atmospheric pollution transport has mainly relied on meteorological and chemical models. However, these models are typically affected by uncertainties due to the assumptions and simplifications inherent in the numerical simulations and source emission estimations. In this study, a comprehensive optical flow framework is developed to offer a new perspective on quantitative characterization of interregional transport of atmospheric pollution based on synergistic observations from geostationary and sun-synchronous satellites. In this framework, the high-frequency continuous aerosol observing images are regarded as video in computer vision, and an aerosol dynamic optical flow algorithm is proposed by incorporating aerosol-specific assumptions and constraints, overcoming the limitation that traditional optical flow methods are typically confined to rigid bodies. Results demonstrate that the developed optical flow framework could distinguish the aerosol transport process from other dynamic processes of aerosol development and accurately capture the fast-changing details of transport processes. Moreover, the satellite-based optical flow framework achieves aerosol transport results comparable to those of widely accepted model-based methods, demonstrating the physical interpretation of pixel-based optical flow results and highlighting its effectiveness in quantitative characterization of the atmospheric pollution transport process via the Aerosol Transport Index (ATI). Furthermore, a case analysis of long-term assessments of interregional transport of atmospheric pollution indicates that Beijing acts as a “sink” of atmospheric pollution, and a downward trend could be found from the annually averaged transported aerosol net loadings due to the emission reduction policy. Compared with model-based methods, the satellite-based optical flow framework is directly grounded in observations and does not rely on emission inventories that take years to update. Therefore, it not only helps improve understanding the patterns of atmospheric pollution interregional transport, but also provides a more efficient and economical way to assess the effectiveness of regional joint control policy.

Single and multi-threaded power flow algorithm for integrated transmission-distribution-residential networks

The rapid development of renewable sources has significantly increased interdependencies between electricity networks of all voltage levels, leading to bidirectional flows between transmission and distribution networks, and requiring analysis of Integrated Transmission-Distribution (ITD) network. The interconnectivity is further amplified by additional coupling with electricity, gas, heat and hydrogen networks, on both national and regional levels. Moreover, installation of solar, wind and storage on customers’ premises has indicated that residential networks need to be included in the overall integrated model, called Integrated Transmission-Distribution-Residential (ITDR) network. The main goal of the paper is to develop a general model of the ITD/ITDR networks and to solve the power-flow problem on large-scale networks in an efficient way. The general model includes three-phase transmission and multi-phase distribution models, as well as accurate control strategies for traditional and electronically coupled electricity resources. The proposed model is solved via novel single-threaded power flow procedure, which incorporates new network elements’ models and the developed algorithm for integrated power flow calculations in different domains. This is further improved by developing a multi-threaded approach. Analyses on a small-scale ITD network have shown that single- and multi-threaded approaches are, respectively, (1.5–4) and (2–5) times faster compared to the state-of-the-art procedures. As network size increases, the efficiency of the proposed multi-threaded procedure becomes more pronounced compared to the single-threaded one (up to 2.39 times).

Prospective observational study on the efficacy and tolerability of a complex of phytochemicals versus dutasteride in the treatment of Lower Urinary Tract Symptomps due to Benign Prostatic Hyperplasia.

The aim of our study was to treat 2 similar groups of patients suffering from BPH: one group with a complex based on phycocyanin, PEA and selenium; the other group with dutasteride. So the effectiveness of these treatments was checked, especially regarding the improvement of LUTS and the reduction of PSA and prostate volume. We included 104 patients in the study. All patients aged between 50 and 70 years, PSA values between 4 and 10 ng/ml, prostate volume calculated by transrectal ultrasound between 50 and 70 cc, flowmetry with maximum flow value greater than or equal to 10 ml/s, no suspicious nodules on DRE, no suspicious lesions on MRI (PI-RADS 1-2), negative previous prostatic biopsies or never bioptied, moreover absence of diabetes mellitus or chronic renal failure (blood creatinine >2 mg/dl). We considered: -Group A of 54 men who used the complex; -Group B of 50 patients treated with dutasteride. Then we controlled all patients 6 months after starting therapy, considering the following parameters: PSA, prostate volume, flowmetry. Our results showed that both dutasteride and complex decreased PSA levels (both had a p<0.0001), with a more significant contribution of dutasteride (mean decrease of -2.743 ng/ml vs -0.971 ng/ml). Uroflowmetry also improved with both ( p<0.0001) with a mean increase in maximum flow of urine of + 3.03 ml/min for the former and + 13.02 ml/min for the latter. Lastly, dutasteride proved to be highly effective on reducing the prostate volume on TRUS (- 22.14 ml, p<0.0001) compared to Ficoxpea, which showed a mean decrease of - 10.04 ml (p<0.0001). Moreover the consistent reduction in prostate volume obtained through the use of dutasteride proved to be more intense than the one obtained by using the complex even in statistical analysis (p<0.0001). Both Ficoxpea and Dutasteride showed reduction of PSA values after 6 months of treatment. The complex based on phycocyanin, PEA and selenium showed a statistically significant improvement in urinary flow, while dutasteride acts more on the volume of the prostate. However, the natural complex is a product with good efficacy on the phlogistic component and does not have the side effects of dutasteride (e.g. gynecomastia, reduced libido). Therefore, we believe it can be used by a large part of the population, in order to reduce LUTS and PSA and improve urinary flow, without side effects.

Numerical study of the vortex-induced vibrations of a cantilevered pipe with a concentrated mass end using a wake oscillator model

In this paper, a numerical study based on a wake oscillator model has been carried out to determine the vortex-induced vibration (VIV) response characteristics of a flexible cantilevered pipe with a concentrated mass at the free end. First, a coupled model consisting of a cantilevered pipe and a wake oscillator is established, followed by discretization of the model and an iterative solution using the second-order central difference method. The displacement response and frequency response characteristics for different flow velocities and concentrated end masses have been compared. The numerical results reveal that the maximum value of the structural vibration displacement occurs at the bottom; i.e., free boundary end, for the cantilevered pipe with a concentrated mass at the free end. The dominant vibration mode typically shows a stepwise increase for an increase of the maximum flow velocity. As the vibration mode is transmitted from a lower order to a higher one, the vibration displacement of the structural end decreases fast. As the concentrated end mass increases, the dominant vibration mode shows a stepwise decrease, and as the vibration mode is transmitted from a higher order to a lower one, the vibration displacement of the structural end experiences a sharp increase.