Search

A new correction method for laser Doppler velocimetry (LDV) measurement volume effects on the time-averaged velocity statistics is proposed by considering the probability density function of streamwise fluctuating velocity and the streamwise cross-sectional area of the measurement volume. The proposed correction method is fundamentally different from previous correction methods using a laser intensity profile of LDV. We propose a simple equation to correct the measurement volume effects. By using the equation and calculating both measurement locations and volumes precisely, the correction for the measurement volume effects on time-averaged velocity statistics can be performed on the basis of LDV measurement data. By comparing with the correction method proposed by Durst et al. (1995), the two correction methods provide almost the same results. In addition, the validity and applicability to high Reynolds numbers or low spatial resolution conditions of the two correction methods are confirmed.

The objective of this paper is to obtain a useful equation which gives a discharge coefficient of a throat-tapped flow nozzle. Experiments for throat-tapped flow nozzles with several different geometric parameters were performed using highly accurate flow facilities at the National Metrology Institute of Japan (NMIJ). The effects of some geometric parameters on the discharge coefficient were experimentally investigated. The parameters include the ratio of the diameter of the pressure taps located at the throat to the throat diameter, the diameter of the pressure taps located at upstream pipe and the roughness of the nozzle surface. Also, the effectiveness of a flow conditioner prescribed in ASME PTC 6 was examined. Although a limitation to the proposed equations was found, the discharge coefficient is affected by the geometric parameters smaller than the measurement uncertainty. Finally, new equations for the discharge coefficient, which cover all experimental results within 0.5%, have been proposed as a set of functions of the Reynolds number.

Streamwise turbulence statistics in the range from Reτ = 990 to Reτ = 20 750 at the High Reynolds Number Actual Flow Facility at the National Metrology Institute of Japan are presented, specifically focusing on the Reynolds number dependence of the inner peak turbulence intensity. Velocity measurements are conducted using laser Doppler velocimetry (LDV), taking account of problems specific to this method, with the aim of providing reliable experimental results. The control volume and the fringe pattern of LDV, both of which influence turbulence statistics, are directly measured using a rotary wire device, and they are used to correct the measured turbulence intensity using methods developed in this study. The present results for mean velocity and turbulence intensity profiles agree well with direct numerical simulation data. The inner peak turbulence intensity in this pipe experiment increases with the increasing Reynolds number. It is found that the Reynolds number dependence of the inner peak up to Reτ = 20 750 is very similar to that in a turbulent boundary layer (TBL). The slope of the outer logarithmic region in the turbulence intensity profile is twice the slope obtained from the relation between the inner peak and the Reynolds number. This relation is also consistent with that for TBL flow.

In transit-time ultrasonic flow meters (TOF), the flow rate is derived from the transit time of an ultrasonic pulse between two ultrasonic transducers. To convert the transit time into flow rate, a profile factor (PF) is required. Because the PF strongly depends on the velocity profile, a precise calibration of the PF is essential to the accuracy of the TOF. Hence, a field calibration, referred to as on-site calibration, is desirable. In this study, a hybrid ultrasonic flow meter that helps calibrate the TOF using ultrasonic Doppler velocimetry (UDV) is proposed for on-site calibration by integrating the velocity profiles over the cross-sectional area of a pipe. Thus, a new system of hybrid ultrasonic flow meter was developed. The maximum flow rate measured using a conventional UDV is significantly lower than that measured using the TOF. Therefore, a system was developed to measure higher velocities and flow rates. The system is novel in that the transit time and velocity profile can be simultaneously measured using a de-aliasing method. To evaluate the influence of the velocity profile on the PF, experiments were conducted under a wide range of flow-rate conditions, which otherwise cannot be implemented using the conventional UDV. To evaluate the influence of the velocity profile in the pipe, an obstacle plate was placed at 8D upstream the test section. Radially arranged measuring lines were employed. The experimental results show that increasing the number of measuring lines did not improve the accuracy of the TOF. On the other hand, the flow rate could be accurately obtained using the proposed UDV by measuring the velocity profile even under distorted flow conditions. Furthermore, the calibration of the PF based on the flow rate obtained using the proposed UDV was found to be feasible.

Main text A supplementary comparison, entitled as APMP.M.FF-S1, has been undertaken between KRISS and NMIJ, AIST under the supervision by the Technical Committee for Fluid Flow (TCFF) in the Asia Pacific Metrology Programme (APMP). The purpose of this supplementary comparison was to prove the measurement equivalence between NMIJ, AIST and KRISS for water flow measurement standards from 300 m3/h to 1 200 m3/h. This supplementary comparison was meaningful because there has not been an international comparison for water flows greater than 300 m3/h. Previous key comparisons have been performed only from 30 m3/h to 200 m3/h [1]. Therefore, this supplementary comparison became the first inter-laboratory comparison to cover the flow range for large-capacity water flow measurement standards. In fact, the inter-laboratory comparison between NMIJ, AIST and PTB (Berlin) has been already done for such flowrate range [2], however, this inter-laboratory comparison has not been supervised by APMP or EURAMET, such that the result of inter-laboratory comparison is published in a research journal, not in the BIPM KCDB for inter-laboratory comparisons. A turbine flow meter with the pipe diameter of 250 mm was chosen as a transfer standard in this supplementary comparison. A flow conditioner was used to define inflow conditions upstream of the turbine flow meter. The flow conditioner was a perforated plate with a well-known design. The turbine flow meter was calibrated in two ways: with or without the flow conditioner. The calibration of turbine flow meter with the flow conditioner was according to the revised test protocol for this supplementary comparison. The other calibration without the flow conditioner was performed to investigate the flow characteristics of the turbine flow meter. K-factor was the measurand to evaluate the measurement equivalence between NMIJ, AIST and KRISS. The K-factor was corrected by considering the temperature change between the water temperature and the reference temperature of 20 oC [3]. The measurement uncertainty of the K-factor included uncertainty factors such as repeatability, day-to-day reproducibility, re-installation effect, long-term stability, and the influence by temperature change. Inconclusiveness test was also performed to see whether the K-factor was suitable for evaluating the number of equivalence between NMIJ, AIST and KRISS. The number of equivalence was found to be less than 1. The number of equivalence became better in the case without the flow conditioner than the case with the flow conditioner. The number of equivalence was found to be conclusive because the inconclusiveness index was less than 2. Therefore, the measurement equivalence between NMIJ, AIST and KRISS has been proven by this supplementary comparison. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

An aim of this research work is to establish an evaluation method concerning a responsiveness of flowmeters for a transient flow rate. To this end, reference flow metering systems for the transient flow are proposed in this paper. Because a behavior of the responsiveness depends on the type of flowmeter, evaluations using different parameters, such as response time to sudden rise and sudden fall in flow rate, response to the frequency and amplitude of flow pulsation, mean characteristic and so on are needed. To achieve a precise evaluation, two reference flow metering methods for transient flow rates are proposed in this paper. One is a high-response weighing method and the other is a velocity profile measurement method using the ultrasonic pulsed Doppler method (UPDM). Since the behaviors of the transient flow rate measured by both methods show good agreement, we conclude them to be useable as a reference flow metering system.

A static weighing system for a liquid microflow calibration rig, whose minimum flow rate is 1 mg/min (equivalent to 1 μL/min for water), was designed and evaluated. The developed weighing system, which can collect over 10 g of water, has two features: (i) an automatic detachable device with a sealing and wiper mechanism in contact with a needle and (ii) a flexible air bag to contain the air from the weighing vessel. Having these two features, the weighing system succeeds in reducing the evaporation effect as well as preventing tension on the weighing scale. However, uncertainty due to the mass difference of adhering liquid on the outside surface of needle before needle insertion and after needle extraction should be considered. Theoretical and experimental analysis were conducted. The mass difference due to the adhering liquid on the needle was estimated to be smaller than 1/3 of the target standard uncertainty of mass measurement set at 0.1 mg, indicating that the detachable procedure was not a dominant uncertainty source for mass measurement. The evaporation rate during collection was experimentally estimated to be less than 0.001 mg/min, which corresponds to less than 0.1% for the lowest flow rate of 1 mg/min.

This paper discusses the influence of decreasing the number density of reflectors on the false detection rate of ultrasound time-domain correlation (UTDC) measurements. False detections are expected to be inhibited when the number density of reflectors decreases. This is because the sidelobe peaks of the cross-correlation coefficient becomes smaller when each pulse can be recognized separately, rather than when some pulses overlap. However, this separated waveform pattern is expected to occur more frequently as the number density of reflectors decreases. This pattern develops because parts of individual pulses exist in the reference window. In this study, the influence of the positional relationship between the pulse and the reference window in the presence of noise was investigated by simulating the UTDC signal process using an assumed pulse waveform. The simulation results show that there is a high probability of an increase in the false detection rate when the pulse length is under approximately 1.7 times the ultrasound period. The simulation results also showed that damped waveform region has a high potential to cause false detection. The flow rate was measured for three different reflector number densities at a national standard calibration facility for water flow measurements in Japan. The conditions under which false detection occurred and the influence on the flow rate error were evaluated. The measurement results showed good agreement with the simulation results. In addition, this paper also presents an application of a new signal processing method for UTDC measurements for reducing the rate of false detections caused by the pulse pattern. The experimental results show that this effectively reduces the flow rate error.

An experimental study on a static pressure measurement errors in wall taps was conducted using a high Reynolds number actual flow facility (Hi-Reff). The bulk Reynolds number ReD examined was up to 1.3 × 107 and tap Reynolds number Ret was up to 8.5 × 104. The behavior of the static pressure measurement error at high Reynolds numbers was clarified experimentally. The static pressure measurement error normalized by wall shear stress increases with Reynolds number and reaches an asymptotic value. Its maximum value is 7.1 at Ret = 8470. The asymptotic value increases with the size of the tap diameter up to 6 mm and then becomes constant for tap diameters exceeding 6 mm. The universal curve reported in previous studies is observed for only a limited range of tap Reynolds numbers of below 700 and of tap diameters below 4 mm.

Bi-comparison for high temperature and high Reynolds number water flows was performed between Physikalische-Technische Bundesanstalt (PTB) and National Metrology Institute of Japan (NMIJ) using differential pressure meters. The flowrate range considered herein was from 250 m 3 /h to 740 m 3 /h and the temperature range was from 20 °C to 80 °C. The Reynolds number based on the pipe diameter ranges from 4.4×10 5 to 3.6×10 6 . The expanded uncertainty of volumetric flowrate with a coverage factor k =2 is 0.040% for PTB and 0.070% for NMIJ. The differential pressure meters as the transfer meter were a throat-tapped flow nozzle and an orifice. The results for both flow meters were in good agreement between the two labs. The difference in the average discharge coefficient at the same Reynolds number ranged from −0.05% to 0.03% for the flow nozzle and from −0.01% to 0.05% for the orifice. The results of the comparison indicate a high level of consistency between PTB and NMIJ for high temperature and high Reynolds number water flows.

In this paper, the results of an inter-laboratory comparison of two small water flow calibration facilities with extremely low uncertainty between Endress+Hauser Japan Co. Ltd. (E+H-J) and the National Metrology Institute of Japan (NMIJ) is reported. Flowrate range between 30 kg/h and 36,000 kg/h is compared. Expanded uncertainty of mass flowrate is from 0.020% to 0.025% at E+H-J and from 0.021% to 0.023% at NMIJ. In order to achieve low uncertainty, NMIJ carries out a re-evaluation of the uncertainty budget for two weighing tank systems. With advanced control of ambient temperature and calibration, the uncertainty level can be reduced to approximately half of previous levels. Results of the inter-laboratory comparison show excellent agreement for both standards, which is less than 0.018%. En values are also less than 0.52 for all examined flowrate points. These results show a high level of consistency for the facilities at both labs. To know the substantial difference, comparison is performed using corrected fitting curves between the flowrate by the test meters and the reference. As a result, significant difference between two facilities was quite small, and is estimated to be less than 0.001%. Differences in this comparison are one or two orders of magnitude lower than previous comparisons on water flow.

To obtain the specific values of the flowrate measurement uncertainty using the ultrasonic Doppler velocity profile (UVP) method under disturbed flow conditions, experimental measurements were performed. To generate a disturbed flow, obstacle plates were installed upstream of the test section. To estimate which experimental parameter dominates the uncertainty, parametric examinations are conducted for the obstacle plate configuration, the distance between the obstacle plates and the measurement section, the incident angle of the ultrasonic beam, and the flowrate. The maximum deviation of the measured flowrate from the reference flowrate exceeds 2% when the flowrate is measured 8D downstream of the obstacle plate. At a distance of 25D downstream, the deviation is within the fundamental uncertainty level of the flowrate measurement using the UVP method. Because several uncertainty factors in this examination are cross-correlated with each other, the uncertainties of these factors are evaluated independently using analysis of variance (ANOVA). The total uncertainty is 7.98%, 1.97%, and 1.14% at 8D, 16D, and 25D, respectively.

The static pressure measurement error at a wall tap of a flow nozzle is examined for a wide range of Reynolds number. The static pressure measurement error is obtained using the measured discharge coefficient for the flow nozzle. The static pressure measurement error is influenced by the diameter of the wall tap and the viscosity of the working fluid. This paper presents several relations between the static pressure measurement error normalized by the wall shear stress and the tap Reynolds number, which is based on the diameter of the wall tap and the friction velocity. The best relation to reasonably explain the static pressure measurement error is proposed in this paper.

The quality of any laboratory intercomparison depends to a large extent on the performance of the used flow meter. To find a flow meter that is capable of reaching a reproducibility better than 0.05% requires bounding all involved influence quantities down to the required level. The present paper describes the efforts performed while qualifying a time-of-flight ultrasonic flow meter as a transfer standard. It was determined that the most relevant influence quantity besides the flow profile within the bulk flow is the effect caused by the transducer pockets in the meter body. By taking advantage of a specially designed window chamber, it was possible to determine the magnitude of the errors introduced by the transducer pockets and to define, based on the findings, a procedure to perform a bilateral comparison between the hot water calibration facilities of the Physikalisch-Technische Bundesanstalt and the National Institute of Advanced Industrial Science and Technology. The results of the bilateral comparison are presented.

After a large heat meter flow test rig was overhauled, making a thorough characterization and re-validation of the associated uncertainty is necessary. Validating the uncertainty through interlaboratory comparisons takes years and is not always successful. Therefore, a method is proposed to validate the uncertainty estimation based on a flow meter Reynolds number similarity in between comparisons. The newly estimated uncertainty of an overhauled facility is schematized and the proposed method is applied. The obtained results are confirmed through a conventional international interlaboratory comparison.

Multipoint laser Doppler velocimetry (MLDV) has been effective for non-invasively measuring the flow velocity distribution with a high-spatial and high-time resolution. The flow velocity can be estimated using a scattered light signal by seeding particles passing through a fringe pattern formed in the intersection region of two laser beams. The shape of this intersection region can be easily changed by changing the optical components and positions of the lasers. An infinitely expanding intersection region is proposed in the present paper. A wide intersection region was indicated by the measurement results of flow velocity. The intersection region is evaluated using a flow channel (1.4 mm × 1.4 mm). The area of the operating measurement region exceeds 150 mm in the horizontal direction and is less than ±10 mm in the vertical direction. This new MLDV is referred to as a large-scale MLDV.

Substituting a carbon atom with a nitrogen atom (nitrogen substitution) on an aromatic ring in our leads 11a and 13g by applying nitrogen scanning afforded a set of compounds that improved not only the solubility but also the metabolic stability. The impact after nitrogen substitution on interactions between a derivative and its on- and off-target proteins (Raf/MEK, CYPs, and hERG channel) was also detected, most of them contributing to weaker interactions. After identifying the positions that kept inhibitory activity on HCT116 cell growth and Raf/MEK, compound 1 (CH5126766/RO5126766) was selected as a clinical compound. A phase I clinical trial is ongoing for solid cancers.

The present paper describes a fundamental uncertainty analysis for a flowrate measurement in a pipe using an ultrasonic Doppler velocity profile method and an evaluation of the estimated uncertainty by an actual flow calibration. The uncertainties are estimated for internal factors originating from the measurement equipment; UVP provided by Met-Flow sa. and external factors depending on on-site measurements, such as the inclination angle of the ultrasonic transducer. The relative expanded uncertainty due to internal factors is estimated to be 0.34% with a coverage factor of 2. The relative external uncertainty including external factors is estimated to be from 0.42% to 2.13% depends on the inclination angle of the transducer. The results of the actual flow calibration under the same condition as the uncertainty analysis are within the range of uncertainty considering the internal factors.

A facile methodology effective in obtaining a set of compounds monofluorinated at various positions (fluorine scan) by chemical synthesis is reported. Direct and nonselective fluorination reactions of our lead compound 1a and key intermediate 2a worked efficiently to afford a total of six monofluorinated derivatives. All of the derivatives kept their physicochemical properties compared with the lead 1a and one of them had enhanced Raf/MEK inhibitory activity. Keeping physicochemical properties could be considered a benefit of monofluorinated derivatives compared with chlorinated derivatives, iodinated derivatives, methylated derivatives, etc. This key finding led to the identification of compound 14d, which had potent tumor growth inhibition in a xenograft model, excellent PK profiles in three animal species, and no critical toxicity.

This study presents a low-frequency ultrasonic propagation analysis using the finite-element method (FEM). Experimental results of flow rate measurements using the ultrasonic velocity profile (UVP) method are also presented. The ultrasound frequency, pipe diameter, and pipe wall thickness are 0.274 MHz, 590.6 mm, and 9.5 mm, respectively. Six waves are generated per ultrasound pulse. To analyze the entire pipe region, the FEM is combined with the Kirchhoff method. The experiments of flow rate measurements are conducted using the high Reynolds number calibration facility at the National Metrology Institute of Japan. The range of the Reynolds number is from 4.4×106 to 1.7×107. Wide spreading of the ultrasonic beam in the axial direction of the pipe is observed because of multiple reflections in the pipe wall. This wide beam affects the measured velocity profile, particularly in the region near the pipe wall. In addition, the flow rate errors are approximately 10% (deviating by 1.1%) across the investigated ...

In this paper, we report on high Reynolds number and highly accurate experimental facilities for turbulent pipe flow established by the National Metrology Institute of Japan (NMIJ). One of the facilities, called the High Reynolds number actual flow facility (Hi-Reff), is capable of handling a maximum bulk Reynolds number of \({Re}_\mathrm{D} = 2.0 \times 10^7\). The most remarkable feature of this facility is its highly accurate flow rate measurements. The expanded uncertainty of the volumetric flow rate is estimated as 0.040–0.10%. Such a low flow rate measurement uncertainty contributes to extremely accurate estimations of inner-scale variables such as friction velocity. This paper presents the details and advantages provided by this NMIJ facility in relation to turbulent pipe experiments.

9-Substituted 6,6-dimethyl-11-oxo-6,11-dihydro-5H-benzo[b]carbazoles were discovered as highly selective and potent anaplastic lymphoma kinase (ALK) inhibitors by structure-based drug design. The high target selectivity was achieved by introducing a substituent close to the E(0) region of the ATP binding site, which has a unique amino acid sequence. Among the identified inhibitors, compound 13d showed highly selective and potent inhibitory activity against ALK with an IC(50) value of 2.9 nM and strong antiproliferative activity against KARPAS-299 with an IC(50) value of 12.8 nM. The compound also displayed significant antitumor efficacy in an established ALK fusion gene-positive anaplastic large-cell lymphoma (ALCL) xenograft model in mice without body weight loss.

This paper reports further experimental results obtained in high Reynolds number actual flow facility in Japan. The experiments were performed in a pipe flow with water, and the friction Reynolds number was varied up to Reτ = 5.3 × 104. This high Reynolds number was achieved by using water as the working fluid and adopting a large-diameter pipe (387 mm) while controlling the flow rate and temperature with high accuracy and precision. The streamwise velocity was measured by laser Doppler velocimetry close to the wall, and the mean velocity profile, called log-law profile U+ = (1/κ) ln(y+) + B, is especially focused. After careful verification of the mean velocity profiles in terms of the flow rate accuracy and an evaluation of the consistency of the present results with those from previously measurements in a smaller pipe (100 mm), it was found that the value of κ asymptotically approaches a constant value of κ = 0.384.