Flow Measurement and Instrumentation最新文献

{"title":"Investigation of contact ratio and dynamic characteristics of non-circular planetary gear train in hydraulic motor","authors":"Yongping Liu ,&nbsp;Linyue Wu ,&nbsp;Changbin Dong","doi":"10.1016/j.flowmeasinst.2024.102720","DOIUrl":"10.1016/j.flowmeasinst.2024.102720","url":null,"abstract":"<div><div>As a basic component of the non-circular gear hydraulic motor (NGHM), the non-circular planetary gear train (NPGT) offers a number of advantages, including low velocity, high output torque and compact design. Two different types of NPGT pitch curves have been designed using the 4–6 type of NGHM as an example. Aiming at two kinds of pitch curves, the contact ratio solution methods for the planetary gear meshing respectively with the sun gear and the inner gear ring are proposed. A comparative analysis of an integrated pitch curve design and a segmented pitch curve design is conducted to evaluate the effects of varying addendum coefficient (AC) and tool tooth profile angle (TTPA) on the contact ratio. Furthermore, the influence of load, velocity, and contact ratio on the dynamic characteristics (DC) of the NPGT with a segmented pitch curve is investigated through dynamic simulation. The results show that AC and TTPA significantly affect the contact ratio, with an increase in contact ratio observed as TTPA decreases and AC increases. Additionally, the load has a notable impact on the dynamic meshing force and its fluctuation. A higher contact ratio is associated with greater transmission stability in the gear train. This study provides a theoretical foundation for the design and optimization of NGHMs, and expands the potential application of contact ratio effects on NPGTs in this field.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102720"},"PeriodicalIF":2.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel technique to resolve directional ambiguity for Particle Streak Velocimetry","authors":"Mumtaz Hussain Qureshi ,&nbsp;Abdul Qadir ,&nbsp;Wei-Hsin Tien","doi":"10.1016/j.flowmeasinst.2024.102712","DOIUrl":"10.1016/j.flowmeasinst.2024.102712","url":null,"abstract":"<div><div>In this study, a novel streak direction-resolving algorithm is introduced to determine the direction of the flow field for a single image frame with multiple streaks. The streak direction was resolved by varying its intensity from 100 % to 50 % of the total intensity of the streak image. This technique was applied to two main types of flows parallel and Hill's vortex flows, parallel flows were divided into further two types constant velocity parallel flow and accelerating parallel flow. The purpose of using different types of flows was to test the robustness of the algorithm with easy and complex flows. The performance of the algorithm was checked by the angular deviation between the true and least-square fitted velocity vectors. The number of correct synthetic streak directions was measured with the success rate in percentage. A high success rate means low angular deviation and a high number of velocity vectors with correct direction was obtained. In this research, four different types of image formats were considered DP (double precision), 16-bit (without noise), 16-bit (1.0 % noise), 16-bit (5.0 % noise), and 8-bit (without noise) and the best results were obtained for DP and 16-bit image formats. The results of the parallel flows indicated a 100 % streak direction success rate, Hill's vortex was a type of complex flow therefore, the algorithm hard to resolve some streak directions due to very low velocities (less than 0.1 px (pixel)/interval) and very high-velocity gradients (greater than 52 px/interval). The observation shows that Hill's vortex synthetic streak images were resolved with a success rate of 92.76 % which means that the majority of the synthetic streaks were resolved. Experimental analysis was also done by using the PDMS microchannel setup. Intensity variation streaks were recorded with long camera exposure time and for maintaining the intensity variation, as the LED switched on maximum illumination was started, and continuous decrement in illumination was set by switching off at 50 % of the total illumination intensity. The best results were achieved with a 94 % success rate. Therefore, the proposed novel approach can be used with less expensive hardware for image processing with a single image frame and is useful for multiple applications.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102712"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unsteady flow and excitation characteristics in a vortex pump","authors":"Xianfang Wu ,&nbsp;Chen Shao ,&nbsp;Minggao Tan ,&nbsp;Houlin Liu ,&nbsp;Runan Hua ,&nbsp;Honggang Li","doi":"10.1016/j.flowmeasinst.2024.102716","DOIUrl":"10.1016/j.flowmeasinst.2024.102716","url":null,"abstract":"<div><div>The impeller in vortex pumps is installed at the side of the volute, which causes the flow instability and vibration. This study employs the Renormalization Group k-epsilon (RNG k-ε) turbulence model to investigate the unsteady flow and excitation characteristics within a vortex pump under various flow rates. The results show that increasing the flow rate reduces the low-pressure area in the vaneless chamber, with flow instability primarily occurring in the middle of the vaneless chamber and intensifying with higher flow rate. Pressure pulsation within the vaneless chamber at nominal flow rate is driven by periodic changes in the vortex structure, occurring at approximately twice the shaft frequency (96Hz). As the impeller rotates, pulsation energy propagates from the vaneless chamber to the tongue and outlet. With increasing flow rates, variations of inlet axial flow velocity cause the rise in pressure pulsation in the vaneless chamber. At high flow rate, pressure pulsation in the vaneless chamber increases tenfold compared to low flow rate. The pressure pulsation at the tongue is significantly smaller than that in the vaneless chamber. The rise in pressure pulsation with increasing flow rates is attributed to the displacement of the circulation flow position towards the tongue.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102716"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation of dissolved oxygen improving aeration efficiency by hydraulic jumps","authors":"Saikat Mondal ,&nbsp;Rajib Das ,&nbsp;Subhasish Das ,&nbsp;Sanchayan Mukherjee","doi":"10.1016/j.flowmeasinst.2024.102715","DOIUrl":"10.1016/j.flowmeasinst.2024.102715","url":null,"abstract":"<div><div>The dissolved oxygen (DO) level in water is vital for water quality and supporting aquatic life. Hydraulic jumps involve rapid flow changes from super-critical to sub-critical, visible at abrupt bed slope shifts, like at spillway bases in rivers or canals. The hydraulic jump efficiently mixes oxygen from air into water and offers a cost-effective method of aeration by entraining air bubbles in the stream to improve oxygen transfer compared to traditional systems. The objective of this experimental research is to investigate the aeration performance with hydraulic jump parameters and establish correlations crucial to measuring aeration (or transfer) efficiency. Relationships between transfer efficiency, jump height, jump length, sequent depth ratio, discharge, inlet Froude number, and channel bed slope were determined. To investigate the nature of such relationships, a series of experiments were conducted in a rectangular tilt flume to test the aeration performance of forced submerged hydraulic jumps with five different discharges and five different smooth bed slopes. The inlet Froude number before the jump varied from 2.18 to 8.23. Experimental observation confirms a positive relationship between transfer efficiency and jump control parameters. During experimentation, transfer efficiency was found to vary between 9.4 % and 34 %. This research includes estimating the optimal transfer efficiency due to hydraulic jumps, which can help hydraulic engineers in building structures that can revitalize any degraded stream.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102715"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a locating method for optical windows in shock tube","authors":"Shijie Bai,&nbsp;Wei Shen,&nbsp;Shilong Li,&nbsp;Xingyu Liang,&nbsp;Kun Wang","doi":"10.1016/j.flowmeasinst.2024.102717","DOIUrl":"10.1016/j.flowmeasinst.2024.102717","url":null,"abstract":"<div><div>A method was proposed in the present study for locating single and/or multiple optical windows in shock tubes. It involved establishing a diagnostic time calculation model by transforming challenging conventional conditions into equivalent special scenarios. The method strategically balanced experimental pressure and optical window locations. Pressure-time history experiments were conducted in a shock tube to verify the reliability of the proposed locating method. An example showcased the versatility of the locating method for determining the positions of single or multiple optical windows. Lastly, the proposed locating method provided evaluation for optimizing several existing shock tube setups.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102717"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CFD-based flow field study and structural optimization of SAC-type ultrahigh-pressure common rail injection steady-state nozzle","authors":"Hailong Ji ,&nbsp;Ruichuan Li ,&nbsp;Wentao Yuan ,&nbsp;Yong Zhou ,&nbsp;Ning Guo ,&nbsp;Dongrun Li ,&nbsp;Qingguang Zhang","doi":"10.1016/j.flowmeasinst.2024.102719","DOIUrl":"10.1016/j.flowmeasinst.2024.102719","url":null,"abstract":"<div><div>This paper constructs and validates a fluid simulation model of fuel in an ultra-high-pressure SAC-type injector using Fluent's CFD computing tool. The effects of different nozzle parameters on the flow field characteristics of ultrahigh-pressure SAC-type nozzles under ultrahigh-pressure 200 MPa operating conditions were investigated. In the context of the study, with the increase of the nozzle diameter, the flowability of the loud nozzle is significantly improved, and the cavitation intensity extended to the outlet will be greater, which is more conducive to the atomization of the fuel. The smaller the nozzle angle, the higher the fuel flow rate, and reducing the angle is favorable to increase the fuel flow rate and mass flow rate. The increase in the inverted radius of the nozzle inlet and the significant increase in the nozzle flow characteristics help improve the nozzle's Circulation performance but are not conducive to the atomization of the fuel. The optimized structure of a Double-crossed oval spray nozzle shape is proposed to reduce the cavitation in the spray nozzle and improve the Circulation performance of the nozzle under a certain cross-sectional area of the outlet of the spray nozzle. The optimized Double-crossed oval spray nozzle mass flow rate increased by16.99 g/s compared with the original nozzle, and the cavitation in the nozzle was significantly suppressed, and the overall average circulation coefficient reached 0.9494, which is 70.23 % higher than the original nozzle, and the Circulation performance of the optimized Double-crossed oval spray nozzle was significantly improved.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102719"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydraulic valve design methodology for hydro turbine control system","authors":"Mateusz Kosek ,&nbsp;Dariusz Downar ,&nbsp;Pawel Sliwinski","doi":"10.1016/j.flowmeasinst.2024.102718","DOIUrl":"10.1016/j.flowmeasinst.2024.102718","url":null,"abstract":"<div><div>The control of the turbine and its equipment in a hydroelectric power plant requires the HPU (hydraulic power unit) to deliver large volumes of working fluid in a short time at specific optimum control parameters. The use of typical proportional flow control valves created by manufacturers of hydraulic components in low-pressure control systems is disadvantageous due to high pressure losses in the control chambers. This paper presents the methodology and test results while designing a hydraulic proportional valve for low pressure and high flow rate operation. CFD (computational fluid dynamics) theory was analyzed and characteristic values were determined. The validation of CFD tests through those on the test bench was carried out, correction factor was determined. A new proprietary solution was developed and a series of simulation studies were carried out to determine the flow characteristics depending on the degree of the opening of the proportional flow control valve.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102718"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orifice erosion effect and variable gain control method for hydraulic servo spool valve","authors":"Xinqiang Liu ,&nbsp;Minghua Qi ,&nbsp;Hong Ji ,&nbsp;Fei Liu ,&nbsp;Guang Lin ,&nbsp;Yao Xiao","doi":"10.1016/j.flowmeasinst.2024.102714","DOIUrl":"10.1016/j.flowmeasinst.2024.102714","url":null,"abstract":"<div><div>The hydraulic servo valve orifice becomes blunted due to erosion caused by solid particle contaminants in the oil, leading to a decline in the valve's static and dynamic performance. This study analyzes the working edge scanning model and proposes using a quarter-ellipse curve to fit the working edge contour for the precise calculation of the valve orifice area. Through AMESim simulation, this study investigates the relationship between valve orifice erosion and the static and dynamic characteristics of hydraulic servo slide valves and proposes a variable gain control method for addressing valve orifice erosion. Results show that the orifice area model based on the quarter elliptic curve is accurate. As erosion increases, the nonlinear area of the valve orifice curve expands, and the valve orifice degrades into a positive opening. The ratio of the long diameter to the short diameter of the ellipse is approximately linearly related to the pressure gain and leakage in the static characteristics of the hydraulic servo valve. After variable gain control, the static and dynamic characteristics of the servo valve closely resemble those of an ideal servo valve, with the maximum deviation between the flow characteristics and the ideal valve orifice approximately 1 %. Regarding pressure characteristics, the pressure drop before the zero position is below 0.2 MPa. This study establishes the internal relationship between orifice erosion and performance degradation and provides a novel approach to enhancing the erosion resistance of hydraulic servo valves.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102714"},"PeriodicalIF":2.3,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of a high-precision linear regulating ball valve","authors":"Zhe Zhao ,&nbsp;Yongguang Liu ,&nbsp;Xiaohui Gao ,&nbsp;Saisai Tong","doi":"10.1016/j.flowmeasinst.2024.102708","DOIUrl":"10.1016/j.flowmeasinst.2024.102708","url":null,"abstract":"<div><div>In this paper, a high-precision linear regulating ball valve is designed from four aspects: positioning accuracy, sealing performance, flow area and flow coefficient. A mathematical expression for the relationship between spool thickness, incision angle and flow coefficient was developed. The correlation matrix <span><math><mi>P</mi></math></span> between the structural parameters and the flow coefficient is obtained by surface fitting. The structural parameters under linear requirements are further determined by determining the P matrix. A more accurate linearization of the flow characteristics was achieved. The CFD data showed that the error of the optimized flow rate with respect to the ideal linear data was less than 0.15 kg/s. The average error was reduced by 43.8% when compared with the minimum error of different structures. The variance decreased by about 58.2% compared to the minimum variance for different structures. The final flow test of the optimized ball valve was carried out. The error between the flow test data and the CFD data is less than 0.14 kg/s and the maximum relative error is about 6.58%.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102708"},"PeriodicalIF":2.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Projection segmentation-based image recognition technology for automatic reading of gas meter","authors":"Yuanming Zhang ,&nbsp;Xiaoxiao Huo ,&nbsp;Qilun Lu ,&nbsp;Guoyu Chen ,&nbsp;Liangyong Hu","doi":"10.1016/j.flowmeasinst.2024.102707","DOIUrl":"10.1016/j.flowmeasinst.2024.102707","url":null,"abstract":"<div><div>In view of the shortcomings of the existing gas meter reading methods, this paper introduces an automatic reading method and calibration device based on the projection segmentation method, which uses the color difference between the character part and the rest part of the last code wheel of the gas meter counter to realize image recognition of the turned characters, and then calculates the cumulative volume indication of gas meter based on the number of turned characters. The pixel projection value scanned by the camera device at the horizontal centerline of the last code wheel changes alternately when the code wheel rotates. The proposed projection segmentation method does not require recognition of specific characters, simplifying the algorithm and making it suitable for most calibration devices. Experiments show that the accuracy rate of the proposed method is 100% even under low-light conditions, which is a great improvement compared with the traditional character recognition method. Additionally, the reading resolution of the proposed method is improved by 10 times compared with the existing photoelectric sampling method and template matching method, and the total calibration time can be reduced by 6.7%–58.7%, which significantly enhances the calibration efficiency.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"100 ","pages":"Article 102707"},"PeriodicalIF":2.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}