Numerous researches on process imaging were done using Light Emitting Diodes (LEDs) based optical sensors, especially in developing optical tomography systems  – . From these previous works, we learned that the image acquisition time is often inversely proportional to the image resolution quality. Hence, in this project, we investigate the use of a simpler yet moderately faster sensing module in order to obtain the particle velocity in a solid-gas flow. The cross correlation technique employed in these previous works will be adapted in this study.
The standard clamp-on flow meter is based on using a single multiple element array which provides for a measurement of the average flow velocity in a pipe. This clamp-on technology has been extended by implementing multiple arrays located at different circumferential positions on a single band, to measure the velocityprofile of the fluid. This new tool offers process operators a non-invasive measurement tool with the ability to monitor and control the profile of their process flow. The following sections summarize the results of flow loop testing and field testing performed on a sonar array profiling system and demonstrates some of the potential benefits, one of which is the ability to detect the onset of sand-out conditions. Early detection of this condition allows operators the time to apply corrective actions and avoid catastrophic process shutdown. In addition, monitoring the profile can provide useful information about the properties of the process fluid which can allow operators to adjust production variables to optimize the process.
The non-invasive tomographic techniques supported additionally by computer methods like tomograms pro- cessing and analysis, cross-correlation etc. designate a standard in velocimetry. The most common solutions are based on resistance and ultrasonic diagnosis. The three-path ultrasonic flow meter for fluid velocity pro- file identification was proposed in . The ability of the first method is sensitive to the flow profile. In case of non-axisymmetric flow, the metering device has to be reinstalled. Otherwise, it indicates that the flow rate is of reduced accuracy and may be unreliable. Similar approach read in  can detect the Doppler shift frequency as a function of time. The authors of this method gave many examples where their solution has already been applied e.g. Flow Mapping of a Recircu- lating Flow in a Square Cavity, stirring and mixing processes in a hyperboloid stirrer vessel, detecting the velocity field in the vicinity of a mechanical valve substitute for simulating pulsatile flow as well as in a 10-mm pipe with raw chocolate and many others. Like- wise, UST and extra convolution algorithm for parallel scan data were applied in  to visualise the velocityprofile of air flow. In , the multiwave ultrasonic excitation was shown to be applied to the autocorrela- tion pulsed-Doppler velocityprofilemeasurement of
At this stage, the designing of graphical user interface will be made by using Visual Basic 6.0. Then, the signal conditioning circuit is interfaced to the DAQ card. Data is captured. DAQ card is used in PC and then the MS Access before it will convert to the Visual Basic 6.0. The offline monitoring of velocity object flowing into the pipe are made. To measure the velocity, cross correlation method is used where the peak of the output from cross-correlation method graph represented the time for the object to move from upstream to downstream. The velocity of the particle is obtained by simply dividing the time and the distance between upstream and downstream.
Another limitation was that data were not collected from spi- nal patients without a syrinx for comparison. Because this was a cross-sectional study and neither prior nor subsequent measure- ments of syrinx dimensions were available from the participants’ clinical records, we are unable to comment on whether syrinxes in the participants were stable. Understanding longitudinal changes in CSF flow measurements and syrinx size in the participants with syringomyelia may help provide insights into the mechanisms of syrinx development, but this was not designed as part of this study. It would also be ideal to compare the CSF velocity-time profile with spinal arterial blood flow to assess the theory that change in the relative timing of arterial blood and CSF pulses is important for syrinx development and progression. 2 However,
Abstract. The main objective of this study was to map the flow field inside the data rack model, fitted with three 1U server models. The server model is based on the common four-processor 1U server. The main dimensions of the data rack model geometry are taken fully from the real geometry. Only the model was simplified with respect to the greatest possibility in the experimental measurements. The flow field mapping was carried out both experimentally and numerically. PIV (Particle Image Velocimetry) method was used for the experimental flow field mapping, when the flow field has been mapped for defined regions within the 2D/3D data rack model. Ansys CFX and OpenFOAM software were used for the numerical solution. Boundary conditions for numerical model were based on data obtained from experimental measurement of velocityprofile at the output of the server mockup. This velocityprofile was used as the input boundary condition in the calculation. In order to achieve greater consistency of the numerical model with experimental data, the numerical model was modified with regard to the results of experimental measurements. Results from the experimental and numerical measurements were compared and the areas of disparateness were identified. In further steps the obtained proven numerical model will be utilized for the real geometry of data racks and data.
The decrease of the average cell velocities with time (Fig.·6) corresponds to the natural variability of cell motility within the population. Indeed, if all the cells were exactly the same, the time taken to reach the camera’s field of view would be different only due to statistical scatter, and the average parameters of the cells located in the observation area would be independent of time, as happens, for example, when sedimentation of identical Brownian particles is observed (Nikolai et al., 1975). In turn, if a population consists of differently swimming cells, faster swimmers generally reach the camera field of view earlier than the slower ones, and the average cell velocities at the beginning of a run are higher than at the end, in agreement with the data shown in Fig.·7; indeed, cells in the upper parts of the measurement area tend to have a higher speed than those in the lower part.
Abstract —The complex, multi-modal and dispersive nature of guided waves makes them extremely effective in the non destructive evaluation of plate-like structures. Knowledge of the dispersion relation of a material is a prerequisite to many guided wave experiments. A frequency-phase velocity map is by far the most useful representation of dispersion. These phase velocity curves can be obtained numerically by solving the Lamb equations, however instabilities and unfamiliarity with the specimen’s parameters makes experimentally obtained dispersion relation desirable. Transformations can be applied to an experimentally obtained frequency-wave number map but it requires prohibitively high number of sampling points in space to resolve modes across the full bandwidth of the transducer. The phase velocity filter described here is able to extract wavelets of a particular phase velocity irrespective of frequency. When applied to the acquisition of dispersion relation, the technique exhibits reduced artefacts and is able to extract modes across the full bandwidth of the excitation. Results show a bandwidth increase of approximately 58%.
A geophysical survey employing seismic refraction and vertical electrical sounding have carried out at the sport center area of Hasanuddin University, South Sulawesi, Indonesia to determine the structural setting and the depth of bedrock at the subsurface using a 12 channel seismograph and Resistivity-meter single-channel Twin Probe Resistivity (G- Sound). The VES has a maximum current electrode separation of 400 m; the result of the survey has enabled the delineation of the bedrock of the area. Data interpretation were using to determine the relationship between electrical and elasticity properties of subsurface in this area. The vertical electrical resistivity has a maximum current electrode of 300 m. The result of the survey has enabled the delineation of the bedrock of the area. The hard rock distinct geo-electrical layer were observed namely volcanic tuff with the resistivity varying from 121Ωm to 735 Ωm with depth ranging from 5.36 m to 7.5 m. the seismic refraction thomography show three layer, the layer with velocity about 1000 m/s interpreted as the volcanic tuff situated at the second layer third layer. For both trends, the resistivity (ρ) and the time propagation per unit length ofp wave ( � obtain that theare relation between electrical properties and the time propagation per unit length. This relation obtained by utilization of porosity parameter. and calculated by least square method.
In the first chamber studied, the calculated velocity mag- nitudes remain constant along the centerline, with a max- imum velocity of 0.0152 m/s for a Reynolds number of 4 (Figure 2). The corresponding wall shear stress magni- tudes vary midplane, along the width of the chamber floor (which is narrower than the others studied, i.e. 2.8 mm as compared to ~14.5 and ~17.7 mm, for chambers 2 and 3 respectively). Looking into the depth of the chamber (Fig- ure 3), wall shear stress magnitudes along the lower sur- face range from 0.2 – 1.05 dyn/cm2 with a mean stress of 0.89 dyn/cm2 (measured midplane between the inlet and outlet). Only 49% of midplane data points (evenly spaced) were within ±5% of the target shear stress; how- ever 72% of the midplane data points fell within 10% of the target stress (Table 2). Shear stress peaks near the inlet/ outlet of the chamber but remains nearly constant (1.02 dyn/cm2) along the centerline of the chamber. The result- ant stress deviates increasingly from the target shear stress, with increasing distance from the centerline of the cham- ber.
As in the general met tional constraints must be imposed (e.g. two object segments be orthogonal) to solve the ill-posed problem. But because the orthographic model is the base of the reconstruction algorithm this gives a possibility to introduce assumptions modeling the measure object. Although to describe the objects illustrated in Figure 29 with one model, the introduction of a huge number of approximations is needed. This will result in a high inaccuracy in the measurement results. Moreover, this method requires that no strong pers
measurements of the acoustic travel time nonreciprocity and to give robust estimates of the depth-averaged flow velocity, despite very limited a priori information about the noise sources and sound propagation conditions. Further research is necessary to improve accuracy and extend the measurements to longer ranges. Anticipated future development of inexpensive low-power atomic clocks should lead to improved accuracy while simplify- ing the analysis. It is expected that wider frequency bands of ambient noise will prove useful for passive measurements on refracted acoustic paths and in less dynamic environments representative of the deep ocean. Flow velocity measurements complement previously demonstrated  passive measurements of the sound speed profile (and, therefore, water temperature) and open the possibility of using acoustic noise interferometry to measure heat fluxes in the ocean.
Figure 6 shows the effect of Prandtl number (Pr) on temperature profiles in stretching case. We infer from this figure that due to higher values of Pr the temperature profile shows different character in different ranges of η . First for small η (η ≤3) , the dimensionless temperature increase with increasing value of Pr and then for large η (η>3) it decreases with increase of Pr.
Abstract. Terrestrial Laser Scanner (TLS) offers a new approach of deformation analysis. Different from conventional equipment such as Global Navigation Satellite System (GNSS) and Total Station (TS), the entire surface of observed structure can be analysed by contactless measurement. However, until recently the application of laser-scanner is still limited to long-term deformation monitoring. Using TLS to monitor dynamic response faces some challenges, such as scan time delay and its data characteristic. This project proposed helical mode to solve these issues and tested the proposed solution in a high-rise artwork deformation monitoring case, the Aspire Sculpture in Nottingham. The result showed that scan time delay can be solved. Then TLS can be used to observe the sculpture dynamic deformation. New approach of point cloud processing was introduced in order to extract the deformation. Using this approach, laser-scanner can be used to monitor dynamic motion of a structure.
The general purpose of the work undertaken was to determine the behaviour of fluids flowing in smooth concentric annuli. The specific problem was that of determining settling length as a function of diameter ratio and Reynolds number for isothermal flow of air at room temperature. The study was based on the assumption that two successive identical velocity profiles constit uted settled flow. This emphasized the need for exact concentricity and uniformity in diameter throughout the annulus. The eccentricity involved in these experiments was less than 3% and the results of Ivey (10), a grad uate student at the University of Windsor, who carried out research on annular flow, indicated that these small order eccentricities had no significant effect on veloc ity profile. The variance in the tube diameter along the length was, of course, minimized by strict selection of tubes and also by using an aluminum tube as a core which had a tighter tolerance than the acrylic tubes
a better tracer of the virial velocity, additional data are required for two case studies: ( 1 ) a large sample of quasars with both host stellar velocity dispersion and broad-line width measure- ments to determine which width de ﬁ nition produces the tightest correlation between the virial product and the stellar velocity dispersion, and ( 2 ) a large sample of quasars with large dynamical range in their continuum variability to test which width de ﬁ nition best follows the expected virial relation ( e.g., Peterson et al. 2004; Shen 2013 ) . Our attempt on this ﬁ rst case study did not yield conclusive results, but future larger samples with both RM and σ * measurements may clarify the situation. The SDSS-RM project will compile multiyear light curves for 849 quasars and thus will provide one of the best samples for the second investigation. In addition, the multiyear data from SDSS-RM will be used to extend our line width study to other broad lines ( such as C IV ) covered in the high-redshift subsample.
Abstract: In this study, computational fluid dynamics (CFD) was used to design the geometry of a new velocity sensor for measuring open channel flows. This sensor determined velocity by observing the travel of dye carried in the flow. Evaluation of this design required the development of fluid dynamics models to determine potential errors in fluid velocitymeasurement due to velocity changes caused by intrusion of the sensor in the fluid. It also required an analysis technique to determine the expected sensor response to the flow fields that resulted from the CFD modeling. These models were then used to improve the geometry of the sensor to minimize the measurement error. Starting with a simple design for the sensor geometry, the CFD analysis modeled the open channel flow around the sensor as turbulent using both the k-ω and k-ε Reynolds Averaged Navier-Stokes (RANS) turbulence models. The model predicted that the original sensor design would underestimate the free-stream velocities of open channels by 7.9% to 2.0% across a range from 0.1 m/s to 5.0 m/s. After using CFD to improve the sensor design, the velocitymeasurement error was limited to less than 4% across the same velocity range. Keywords: computational fluid dynamics, flow measurement, sensors, flow velocity, open channel
The correlation of the DHC Velocity (DHCV) values and transverse yield strengths, used in Eq. (2) proposed by Oh , is a confirmation of our results for the present tubes showing similar tensile strengths and DHCV. The susceptibility to DHC cracking of Zr-2.5 Nb materials, hydrided at the same hydrogen level and tested in identical conditions is similar if the mechanical behaviour is identically.
Signals V out , a and V out , b were each rectified and low pass filtered to produce d.c. output voltages V a and V b which could be subsequently cross correlated to provide information on the mean dispersed phase velocity (of a two phase flow) at the particular region of the flow cross section ‘interrogated’ by planes A and B. By changing which electrodes in planes A and B were V + , ve or E electrodes, different parts of the flow cross section could be interrogated. A dedicated MATLAB ‘m-file’ module was used to perform cross correlation of the signals received from the two planes.