Head Of Turbinate Research Articles

The Anaesthetic Efficacy of Tetracaine and Oxymetazoline Compared With Co-Phenylcaine in Healthy Individuals.

Nasal anaesthetic-decongestant sprays are commonly used prior to nasal instrumentation, such as flexible and rigid nasal endoscopy. Co-phenylcaine (lignocaine 5%, phenylephrine 0.5%, ENT Technologies Pty Ltd., Melbourne, VIC, Australia) is a combination spray commonly used for this purpose. However, lignocaine is less potent than other local anaesthetics, and both active constituents of Co-phenylcaine have a bitter taste. It was hypothesised that a combination spray containing tetracaine and oxymetazoline would both offer more potent topical anaesthesia and have a better taste. Four anaesthetic-decongestant nasal sprays were tested in 10 healthy participants (Co-phenylcaine, and tetracaine 0.5%, 1% and 2% with oxymetazoline 0.05%). Sensory thresholds were sequentially measured at the head of the inferior turbinate using Semmes-Weinstein monofilaments over the following hour. Participants also rated taste on a Likert-style scale, and reported whether they experienced subjective numbness of the maxillary teeth. A median peak sensory threshold of 60 g (the maximum tested) was observed with Co-phenylcaine, but this threshold was exceeded by all the tetracaine-based sprays. Tetracaine 2% with oxymetazoline 0.05% had a significantly more rapid onset than Co-phenylcaine (4 min vs. 6 min, p < 0.05) and a longer duration of action. Eight participants reported dental numbness after administration of tetracaine 2% with oxymetazoline 0.05%, but only one participant after Co-phenylcaine. Tetracaine-based sprays were generally perceived to taste less unpleasant than Co-phenylcaine. Tetracaine 2% with oxymetazoline 0.05% is a more potent and rapidly acting anaesthetic-decongestant spray than Co-phenylcaine, with a longer duration of action.

CT comparison of the nasal airway anterior and posterior to the piriform aperture in patients with and without nasal obstruction

BackgroundNasal airway stenosis may lie anterior and/or posterior to the piriform aperture. We intended to compare the nasal airway anterior and posterior to the piriform aperture in patients with and without nasal obstruction.MethodsSegmented computed tomography cross-sectional areas of the nasal airway anterior (CT-CSAant) and posterior to the piriform aperture (at the level of the head of the inferior turbinate; CT-CSApost) were compared between patients with nasal obstruction (cases) and trauma controls. CT-CSA were approximately perpendicular to the direction of the nasal airflow. Anterior to the piriform aperture, they were tilted about 30o, 60o and 90o to the nasal floor. Posterior to the piriform aperture, they were tilted about 50o, 80o and 100o to the nasal floor. In cases, we examined the Pearson’s correlation of active anterior rhinomanometry with CT-CSAant and CT-CSApost.ResultsNarrow and bilateral CT-CSApost were similarly large between 56 cases and 56 controls (all p > 0.2). On the contrary, narrow and bilateral CT-CSAant were significantly smaller in cases than in controls (all p < 0.001). The ratio of the size of CT-CSAant−30 to that of CT-CSApost−80 was significantly lower in cases (median: 0.84; lower to upper quartile: 0.55–1.13) than in controls (1.0; 0.88–1.16; Mann-Whitney U test; p = 0.006). Bilateral CT-CSAant correlated significantly with total inspiratory flow (all p < 0.026) in contrast to bilateral CT-CSApost (all p > 0.056).ConclusionsThe nasal airway anterior to the piriform aperture was smaller in patients with nasal obstruction due to skeletal nasal stenosis than that in controls. On the contrary, the nasal airway posterior to the piriform aperture was similarly large between patients with and without nasal obstruction. Furthermore, in patients with nasal obstruction, the anterior nasal airway was narrower compared to that located posterior to it. On the contrary, control patients’ anterior nasal airway was as large as the posterior one.

Pengaruh Jarak Antar Ulir Terhadap Daya Output Pada Turbin Archimedes Screw

The need for energy sources currently continues to increase, especially electrical energy, even exceeding existing estimates. Along with the need for electrical energy, further research is needed to utilize new renewable energy as alternative energy, one of which is hydroelectric power plants. Hydropower and PLTMH have different output capacities, one of the turbines that can be used as a PLTMH is the screw turbine (Archimedes screw). The efficiency of the Archimedes screw turbine is influenced by many factors, one of which is the turbine design. The existing turbine design needs to be evaluated by several factors such as inner and outer screw diameter, slope, screw pitch, number of blades, and inlet and outlet conditions as well as head and water flow. This research aims to find out how the design of the distance between the screws affects the efficiency of this screw turbine. The variable used in this research is the distance between threads, namely 8 cm, 10 cm, and 12 cm with a 12VDC 5W, 10W, and 15W lamp load. The results of this research show that the turbine with a distance between the threads of 12 cm produces the highest generator rotation, namely 532.1 rpm at no load and at a load of 15 watts the rotation decreases to 227.1 rpm. The highest voltage produced is 27.1 Volts when there is no load and when the load is 15 watts it is 8.9 Volts. while the current and power are 0.64 Ampere 5.70 Watt respectively, so that the highest efficiency is produced in a turbine with a screw spacing of 12 cm at a turbine head angle of 40 , namely 10.10%.

Improved Operation and Method of a Reaction Turbine for Enhancing Net Head

In a reaction turbine, the amount of energy harnessed depends on discharge and net head. The two variables are mutually exclusive or in which one variable is dependent on another and in which the increase of head will decrease the flow required by the hydraulic turbine or vice versa. There is a need for improving the existing hydropower system and the method for enhancing the net head of a reaction turbine is essential. The present invention will hold the key in novelty during the design and excavation of tail race channel or for Renovation, Modernization and Uprating (RMU) of the existing old hydro power plants. The proper redesign of tail water channel, selecting suitable width, depth and by adopting flow regulating means will yield improve the net head substantially and thereby saving of discharge to an extent. The present invention enables to improve net head and saves discharge considerably, thereby enhancing the capacity factor of the hydro plant. The novelty and the innovation is granted an Indian patent for the method of enhancing the net head of a reaction turbines.

A Radiological Study on the Location of Sphenopalatine Foramen in Koreans

Background and Objectives Endoscopic ligation or cauterization of the sphenopalatine artery (SPA) is used to treat intractable bleeding. Acquisition of intranasal anatomical landmarks can be helpful for locating the sphenopalatine foramen (SPF). The purpose of this study is to evaluate the clinical usefulness of endoscopy by selecting the radioanatomical landmarks for the location of the SPF.Subjects and Method Sinus CT was performed on a total of 271 people, and a study was conducted on bilateral 542 sides. In this study, seven landmarks included third lamella, posterior choana, posterior fontanelle, maxillary line, anterior head of middle turbinate, nasal floor, and bony attached part of inferior turbinate. The distances from the seven landmarks to SPF were measured, respectively. Additionally, the distance from the anterior nasal spine to SPF and the angle between the nasal floor and SPF were measured.Results The horizontal position of SPF was located at the middle point between the posterior choana and the third lamella, and the vertical position was around 13-14 mm upward from the bony attached part of the inferior turbinate. For the performed middle meatal antrostomy, the distance from the posterior fontanelle to SPF was around 12-13 mm behind. The average distance from the anterior nasal spine to SPF was 46.47 mm, and the angle between the nasal floor and the SPF was 29.76°.Conclusion The four landmarks, namely the posterior choana, third lamella, bony attached part of the inferior turbinate, and posterior fontanelle can be useful for locating SPF.

Experimental comparison of the upstream head using the non-rotating model of the vertical ultra-low head hydro turbine with its prototype

A vertical ultra-low head (VULH) turbine is a pico-scale hydro turbine applicable to open canal flow with or without head drop. This conceptualized turbine rotates at a lower speed. In the case of water flow on a canal without head drop condition, the prediction of the upstream head is challenging due to the change in the direction of the water flow path on this conceptualized system. Assuming the head at the primary level of design, an experimental study has been conducted to judge the upstream head of water flow using the two-dimensional non-rotating model (NRM) before the use of a prototype of the turbine. The runner was designed with a conventional method whereas the design of NRM was based on the diameters of the runner designed and the orifice openings on it. The experiments were conducted on a newly developed VULH Turbine test rig of size 10 m x 1.5 m x 2 m with a maximum flow rate capacity of 120 LPS and a maximum upstream head of 0.75 m. The tests were completed for upstream head variation using three different sets of NRM having an orifice cut angle of 15°, 18°, and 22.5° and a prototype of the runner at a constant speed for different flow rates. From the comparisons made, the closest NRM was selected that showed a similar upstream head at the maximum efficiency point of the runner. The research concluded with the finding that the NRM can be used to predict the upstream head of the VULH turbine instead of the rotating model.

Cell Type Catalog of Middle Turbinate Epithelium (Cell Catalog of Turbinate Epithelium)

AbstractObjectiveSingle‐cell RNA‐sequencing of middle turbinate mucosa was performed to create the first single‐cell transcriptome catalog of this part of the human body.Study DesignBasic science research.SettingSingle center, tertiary care center.MethodsSamples were obtained from the head of the middle turbinate from a healthy volunteer. After the specimen was prepared per lab protocol, cells were dissociated, resuspended, and counted. Single‐cell libraries were then prepared according to the 10x Genomics protocol and sequenced using NovaSeq 6000 (Illumina). Sequencing data were processed using Cell Ranger, and clustering and gene expression analysis was performed using Seurat. Cell types were annotated through expression profiling of single cells using known markers and data from other single‐cell studies.ResultsFourteen unique cell types were identified, including serous, goblet, club, basal, ciliated, endothelial, and mesenchymal cells, as well as multiple types of blood cells.ConclusionThis catalog provides a comprehensive depiction of the cellular composition of middle turbinate mucosa. By uncovering the cellular stratification of gene expression profiles in the healthy middle turbinate epithelium, the groundwork has been laid for further investigation into the molecular pathogenesis and targeted therapy of sinonasal disease.

In Vivo Fluticasone Absorption in Surgical Patients.

Intranasal corticosteroids (INCS) are a treatment mainstay of chronic rhinosinusitis and allergic rhinitis. Current computational models demonstrate that >90% of INCS drug deposition occurs on the head of the inferior turbinate and nasal valve, rather than the actual sinuses. These models do not consider mucociliary clearance which propels mucus posteriorly, nor do they consider the absorption of the drug. The purpose of this study is to better understand the exact anatomical location where INCS are absorbed. Patients with chronic rhinosinusitis and allergic rhinitis taking fluticasone pre-operatively who were scheduled for functional endoscopic sinus surgery and inferior turbinate reduction, respectively, were recruited. Intra-operative tissue samples were obtained from predetermined locations within the sinonasal cavity. Mass spectrometry was then used to quantify the amount of absorption in each specific anatomic location to determine the largest amount of absorption. Eighteen patients were included in our study. The greatest fluticasone absorption levels across the sinonasal anatomy were at the anterior inferior turbinate (5.7 ngl/mL), ethmoid sinus, (4.4 ng/mL), posterior inferior turbinate (3.7 ng/mL), maxillary sinus (1.3 ng/mL), and the sphenoethmoidal recess (0.72 ng/mL) respectively. Absorption was significantly higher in revision surgery compared to surgically naïve patients. Computation fluid dynamic models of the nasal passage are useful models to help predict intranasal particle flow. However, these models do not incorporate or consider the important mucociliary clearance system, leading to absorption of fluticasone throughout the sinonasal cavity far beyond that predicted by these models. 2 Laryngoscope, 134:1551-1555, 2024.

How Does Oxymetazoline Change Nasal Aerodynamics and Symptomatology in Patients with Turbinate Hypertrophy?

Oxymetazoline relieves nasal obstructive symptoms via vasoconstriction, however, the changes in nasal structures and aerodynamics that impact symptoms the most remain unclear. This prospective, longitudinal, and single blinded cohort study applied Computational Fluid Dynamic (CFD) modeling based on CT scans at baseline and post-oxymetazoline on 13 consecutive patients with chronic nasal obstruction secondary to inferior turbinate hypertrophy from a tertiary medical center. To account for placebo effect, a sham saline spray was administered with subject blindfolded prior to oxymetazoline, with 30 min rest in between. Nasal Obstruction Symptom Evaluation (NOSE) and unilateral Visual Analogue Scale (VAS) scores of nasal obstructions were collected at baseline, after sham, and 30 min after oxymetazoline. Both VAS and NOSE scores significantly improved from baseline to post-oxymetazoline (NOSE: 62.3 ± 12.4 to 31.5 ± 22.5, p < 0.01; VAS: 5.27 ± 2.63 to 3.85 ± 2.59, p < 0.05), but not significantly from baseline to post-sham. The anatomical effects of oxymetazoline were observed broadly throughout the entire length of the inferior and middle turbinates (p < 0.05). Among many variables that changed significantly post-oxymetazoline, only decreased nasal resistance (spearman r = 0.4, p < 0.05), increased regional flow rates (r = -0.3 to -0.5, p < 0.05) and mucosal cooling heat flux (r = -0.42, p < 0.01) in the inferior but not middle turbinate regions, and nasal valve Wall Shear Stress (WSS r = -0.43, p < 0.05) strongly correlated with symptom improvement. Oxymetazoline broadly affects the inferior and middle turbinates, however, symptomatic improvement appears to be driven more by global nasal resistance and regional increases in airflow rate, mucosal cooling, and WSS, especially near the head of the inferior turbinate. 3: Well-designed, prospective, single blinded cohort trial. Laryngoscope, 134:1100-1106, 2024.

Hydraulic performances of a bulb turbine with full field reservoir model based on entropy production analysis

Bulb turbines are used to generate electric power, usually in low-head hydropower as a renewable source of energy. Flows in the turbines are typically characterized by low Froude number, so the pressure fields are more governed by the hydrostatic pressure gradient relative to the turbine head. As a result, the head loss mechanism is difficult to be identified by comparing local pressure characteristics, especially for vertical distributions. Furthermore, turbine flows are more sensitive to flows in reservoirs, due to shorter penstock lengths and larger runner diameters. In practice, the performances of each turbine obviously differ in a low-head hydropower station. The present paper analyzes hydraulic performance of a bulb turbine prototype, based on the entropy production theory. The full field reservoir modeling is conducted based on the two-phase flow simulation method and the geometric and environmental factors during multi turbine operation (5 units). The results showed the usefulness of the entropy production analysis for analyzing flow interactions between turbine and reservoir flows but also between each turbine unit. And, it showed that the flow interaction could play a noticeably strong role in determining operating conditions as well as the entire available energy in low-head hydropower stations.

Experimental investigation of an adjustable guide vane system in a Francis turbine draft tube at part load operation

Hydraulic turbines are increasingly used to regulate the electrical grid. They thus have to operate more often at off-design conditions where instabilities may develop leading to large pressure pulsations decreasing the life of the machines. In the present study, an adjustable guide vane system in the draft tube of a single regulated hydraulic turbine is developed. The aim is to mitigate the pressure pulsations when the turbine operates at part load operational regimes without significantly compromising the hydraulic efficiency of the turbine. The draft tube guide vane system, named DTGV, is composed of three guide vanes. Each guide vanes comprise two individual hydrofoils. The upper hydrofoil can rotate around an axis up to ±45°, and the lower is fixed. Therefore, the guide vanes are adjustable. The rotating vortex rope mitigation was investigated at two part-load operational regimes at a 12 m turbine head, a) Q/QBEP = 0.59, and b) Q/QBEP = 0.71. The results indicate that the DTGV system significantly mitigates the pressure pulsations, thereby improving the flexible operation of the turbine. The best mitigation outcome was for 0 GV configuration at both part-load operating conditions. The mitigation effects are better when the operating condition approaches BEP, and the rotating mode of the pressure pulsations tends to go towards the runner frequency (f/f0 = 1). The hydraulic efficiency is found to be marginally affected by the guide vane system at part load operations and is improved at the best efficiency point (Q/QBEP = 1) and high load Q/QBEP = 1.21.

Fish damage due to tubular turbine: Experiments and CFD simulations

Fishes passing through a tubular turbine could eventually be damaged by mechanisms such as impact (s), pressure change (A), pressure gradient (B), and shear stress (C). In the study, the damage of the test fish under different pressure conditions is investigated by pressure tests, and the damage thresholds derived from the tests are combined with CFD simulations to further quantify the fish damage mechanisms caused by the tubular turbine under plausible flow rate and head conditions. Pressure tests show the anatomy of the fish (>94%) remains normal if the induced pressure is between −0.015 and 0.68 MPa. However, the induction of larger negative pressures significantly hampered fish health, with 90% of fish dying at −0.075 MPa 1.5 days after the test and 100% 6 days after the test. Additionally, CFD simulation results show that fish are more vulnerable to blade impact than other mechanisms, with the highest injury probability of 11.02%, and this trend decreases with the increase of turbine head, flow rate and guide vane opening. Negative pressure and pressure gradient are the secondary factors, with the highest probability of 6.45% and 4.61%, respectively. Shear stress is the most insignificant factor, with the highest damage probability of only 0.00699%.

Transient simulation of the rapid guide vane adjustment under constant head of pump turbine in pump mode

In order to understand the flow mechanism of pump turbine during the rapid guide vane adjustment (RGVA), the shear stress transition (SST) k-ω turbulence model was used for transient simulation. The dynamic mesh technique was used to simulate the closing process of the guide vane. Combined with the verification of grid independence and the validation of experimental results, the variations of performance parameters (head, flow, torque), entropy production rate and pressure pulsation were calculated. And this process can be basically divided into three stages, including the preparation stage before the guide vane closing (Stage I), the guide vane closing stage (Stage II) and the completion stage of the guide vane closing (Stage III). The numerical simulation results showed that the performance parameters were varying in the form of exponential function during RGVA. The variation trend of the torque of each guide vane in the Stage II is basically the same, but the pulsation intensity in Stage III is different. In the Stage II, the guide vane is the component with the largest change in hydraulic loss, rising by about 362.5 %. The high energy dispersion sites are filling the flow passages of the guide vanes and the static vanes. The position with high pressure pulsation amplitude in the vaneless region also shifted, and the offset angle was 2–3°. The composition and evolution of the vortex structure in the vaneless region and the flow passage are determined by the Q-criterion. These structures, including horseshoe vortex and spanwise vortex, are the main reasons for the increase of pressure pulsation amplitude.

System and method for enhancing a net head of a reaction turbine

The most useful form of renewable energy is Hydropower. This holds 16–20% share of total energy generation. Reaction type hydro turbines are predominantly used due to its advantages on the operation under high flow and low/medium head and high discharge. This paper proposes a system and method for enhancing a net head of a turbine by the way of proper design consideration of tail race channel. The system includes a reaction turbine including scroll casing, guide vanes, and a draft tube. Further, the system also includes a first flow regulating means which reduces a water level in the tailrace to a minimum threshold level from a maximum threshold level when the reaction turbine is operating at a load power corresponding to a high load and maintains the water level in the tailrace to the minimum threshold level to avoid cavitation during the flow of water in the tailrace, thereby enhancing the net head of the reaction turbine. The guide vanes and multiple runner blades reduce a flow rate of the water discharged from the draft tube upon operating on an arrangement of the guide vanes and the multiple runner blades, upon enhancing the net head of the reaction turbine.

Injection of Platelet Rich Plasma in the Olfactory Cleft for COVID-19 Patients With Persistent Olfactory Dysfunction: Description of the Technique.

In this paper, we described technique of platelet rich plasma injection into the olfactory cleft in a 22-year-old female with 24-month post–COVID-19 anosmia. The technique starts with the blood extraction and the isolation of PRP through a 10-min centrifugation. The supernatant was injected in nasal regions after a local anesthesia through a 0° rigid optic. Several points of .2–.5 mL were performed in the nasal septum in regard of the head of the middle turbine and in the head of the middle turbine in both sides. The baseline threshold, discrimination, and identification scores were 1, 8, and 0, and the Olfactory Disorder Questionnaire score was 51, respectively. The injection of PRP in olfactory cleft was done without complication and mild pain. The patient perception of recovery of smell sense occurred at 3-week post-injection. From this time, the smell sense progressively improved to the 2-month consultation. At 2-month post-injection, the TDI scores reached 16, 16, and 16 (48), while the Olfactory Disorder Questionnaire was 73. The injection of PRP into the olfactory cleft appears to be a safe and easiness new approach that may improve the recovery of smell sense. Future controlled studies are needed.

Research and application of deformation measurement method of hydraulic turbine head cover

Aiming at the deformation of hydraulic turbine head cover during operation, a non-contact eddy current sensor is proposed. In this method, the turbine pit wall is taken as the static reference point, a fixed support is erected on it, and the eddy current probe is fixed at the other end of the support. Measure the gap change between the eddy current sensor probe and the head cover to calculate the absolute deformation of the head cover. The effectiveness of the proposed method is verified by taking the lifting amount test of hydraulic turbine head cover in a power plant as an example. The results show that this method has the characteristics of simple test equipment, strong adaptability and high accuracy, and can be applied to the field test of hydraulic turbine head cover deformation.

Experimental Investigation and Performance Characteristics of Francis Turbine with Different Guide Vane Openings in Hydro Distributed Generation Power Plants

This article presents a study on the performance characteristics of a Francis turbine operating with various guide vane openings to determine the best operating point based on unit quantities. The guide vane openings were specified based on the width between the vanes at their exit, i.e., 10 mm, 13 mm, 16 mm, and 19 mm. The performance characteristic curves of the Francis turbine—head versus speed, torque versus speed, discharge versus speed, and efficiency versus speed—were obtained at various input power and guide vane openings. From these data, unit curves were plotted and the corresponding best efficiency points were obtained. The highest efficiency of 50.25% was obtained at a guide vane opening of 19 mm. The values of head, discharge, speed, and output power at BEP were 7.84 m, 13.55 lps, 1250 rpm, and 524 W, respectively.

Hydraulic Performance of a Francis Turbine with a Variable Draft Tube Guide Vane System to Mitigate Pressure Pulsations

The present paper demonstrates a proof-of-concept by introducing a variable guide vane system in the draft tube of a high-head Francis model turbine. The aim is to examine the hydraulic performance of the turbine while mitigating the pressure pulsations in the draft tube. The guide vanes can rotate about an axis up to ±45°. The pressure pulsations mitigation studies were performed at lower- and upper-part loads. The hydraulic performance was examined at all operating ranges within the turbine head. There were six guide vane configurations considered between ±45°. The findings demonstrate that the highest efficiency loss with a guide vane configuration that mitigates the pressure pulsations is marginal, with modest improvements at the best efficiency point. The pressure pulsations are 100% mitigated at the lower part load, and there is a maximum decrement in the pressure pulsations up to 80% at the upper part load. The study demonstrates that such a system can improve the operational flexibility of the hydro-turbine by mitigating the pressure pulsations and marginally affecting its hydraulic performance.

Optimization design of the elbow draft tube of the hydraulic turbine

The draft tube of the hydraulic turbine serves to recover the kinetic energy of the water flow that leaves the runner. The amount of this energy depends on the turbine type, its specific speed and flow capacity. For high specific speed turbines, influence of the draft tube on the turbine efficiency is more essential. The height of the elbow-type draft tube has a considerable influence on its performance. Statistics show that increasing the height of the draft tube leads to a considerable increase of the turbine efficiency, but it also increases the scope and cost of civil works. The present paper presents the solution of the multi-objective optimization problem directed to minimization of the height of the toroidal elbow-type draft tube and maximization of the overall efficiency of the turbine. During optimization, 11-19 parameters that determine the shape and dimensions of the draft tube were subject to variation. In optimization, efficiency was maximized in two operating points: best efficiency point and full-load point. Cavitation qualities were defined as constraints. In order to correctly assess the turbine efficiency and cavitation, the computational domain included one channel of the distributor, one channel of the runner and draft tube; whereas losses in the spiral case and stay ring were determined using empiric formulae. Within the optimization the flow analysis was performed using 3D steady-state Reynolds averaged Navier Stokes equations closed by the k-ε turbulence model. On solid walls the method of wall functions was used. The turbine head, being the difference of specific energies in the inlet and outlet cross sections, was pre-set as a constant value, while the discharge was determined in the course of solution of the problem. A multi-objective genetic algorithm was used to solve the optimization problem. For the draft tube shapes obtained in the course of optimization, their performance characteristics and flow character were compared by means of CFD. It was found that it is possible to significantly reduce the height of the classical toroidal draft tubes without considerably affecting their performance characteristics.

Multi-objective optimization of guide vane closure scheme in clean pumped-storage power plant with emphasis on pressure fluctuations

In this study, multi-objective optimization was conducted for the guide vane closure scheme during the load-rejection process of a pump turbine, considering pressure fluctuation, maximum rotational speed, maximum pressure at the volute, and minimum pressure at the draft tube inlet to decrease the low-frequency high-amplitude pressure fluctuations at conditions near no-load. Two quantitative indicators, minimum discharge (Qmin) and the ratio of rotational speed to hydraulic head (NDH) of the pump turbine, were proposed to represent the backflow-induced pressure fluctuations. Two objective functions were defined to optimize the guide vane closure scheme and two optimized guide vane closure schemes, OPS-Q (based on Qmin) and OPS-NDH (based on NDH), were developed. The enhancements resulting from these vane closure schemes were verified using a one-dimensional–three-dimensional coupling flow simulation method. NDH was revealed to comprehensively represent backflow-induced pressure fluctuations, whereas Qmin partially represented the backflow. Consequently, OPS-NDH suppressed the pressure fluctuations by appropriately increasing the maximum pressure at the volute and the maximum vacuum at the draft tube inlet within the allowance ranges of the pumped-storage power plant. OPS-Q suppressed the pressure fluctuations; however, the minimum pressure at the draft tube inlet could not be controlled to satisfy the design requirements of the pumped-storage power plant. The findings of this study can be used as a theoretical reference for suppressing the pressure fluctuations in a clean pumped-storage power plant under near-no-load conditions.