Imaging of fluid flow by tomographic reconstruction using enhanced multipath ultrasonic measurements (original) (raw)

Application of transmission-mode ultrasonic tomography to identify multiphase flow regime

2011

This paper presents an application of ultrasonic tomography where the main objective is to identify the multiphase flow regime which is liquid, gas and solid at once. The system was designing non-invasively by using offline method. The transmission mode with fan shaped beam back projection had been implemented for sensing purposes where 8× 8 projections were produced. Beside, the linear back projection (LBP) algorithm was implemented in the software system for the image reconstruction part. Experiments show ...

Initial Study On Ultrasonic Tomography For Multiphase Flow Application

Jurnal Teknologi, 2011

OSU prw^kk^I=era^_fv^eI=g^vprj^kI=jlea=e^cfw=C=v^pjfk== daripada projek ini menunjukkan bahawa kondisi dan komposisi aliran yang berbeza akan memberikan bacaan voltan keluaran yang berbeza. Ini disebabkan oleh galangan dan halaju setiap bahan adalah berbeza. Hasil dan analisis kajian boleh digunakan untuk kajian dan penyelidikan yang lebih mendalam ke atas sistem tiga fasa.

A MultiPath Ultrasonic Transit Time Flow Meter Using a Tomography Method for Gas Flow Velocity Profile Measurement

Particle & Particle Systems Characterization, 2006

A velocity profile is the distribution of velocities in the axial direction over a cross-section of circular pipe. In this study, a new ultrasonic flow meter with a modified multi-path configuration, namely, a tomographic ultrasonic flow meter is proposed for the measurement of the flow velocity profile. The flow meter consists of a set of transmitting transducers and a set of receiving transducers placed at different positions on the pipe surroundings. This configuration produces an ultrasonic path in various directions and positions for the flow detection. Transmitting transducers, in sequence, propagate the ultrasound wave to all receiving transducers, and the axial velocity in each ultrasonic path is measured. The average velocity is calculated by using the weighting method. Using the theoretical flow profiles, the tomographic ultrasonic flow meter is simulated in asymmetric flow and compared to both the diametrical and quadrature configurations. The filtered back projection method is employed to reconstruct a flow velocity profile. In the reconstruction process, the flow velocity obtained in each ultrasonic path is used as the projection data. An experiment is also performed in a circular pipe for measuring the air flow velocity profile, in order to validate the proposed flow meter.

Image reconstruction technique for ultrasonic transmission tomography

2016

Precise flow control has always been a necessity for developing easier approaches or instrumentation for two-phase flow regime. An important method for monitoring this process is called process tomography such as electrical tomography, optical tomography and ultrasonic tomography (UT). In the case of high-acoustic impedance mixtures e.g. bubbly flow, UT has the advantages in monitoring real time data. Although various researches were conducted using UT systems in bubbly flow regimes, there are still weaknesses especially in real time image reconstruction techniques for monitoring the process. Some efforts such as linear back projection (LBP), filter back projection (FBP), convolution back projection (CBP) and iterative techniques are utilized for reconstructing the image with few views data for UT system. Regardless of the utilized method there still exist two main issues in UT image reconstruction both in forward and inverse problems. In the case of forward problem, the gaps betwee...

An Ultrasonic Transmission/Reflection Mode Tomography for Two-Phase Flow Measurement

International Journal of Industrial Electronics, Control and Optimization (IECO), 2022

The ultrasonic process tomography obtains the distribution of two-phase flows based on ultrasound propagation in different fluids, so it is valuable for industrial monitoring and measurement. It can do a non-intrusive exploration of the multi-phase flow hydrodynamics. This paper presents a dualmode ultrasonic process tomography that fuses reflection-mode tomography and time-of-flight ultrasonic tomography. In this method, a 32-digit array of ultrasonic sensors is used for flow measurement. The two-phase flow rate that involves liquid and gas phases is calculated by a simple algebraic algorithm with the data obtained from sensors. Simulation results reveal that the measurement technique is independent of the fluid flow pattern and the system error is also decreased. The contribution of the article is the introduction of a simple algebraic method for image reconstruction for which no special case is considered and simultaneously, the image reconstruction error is reduced. The relative error of the reconstructed images is presented by MATLAB simulation and it is much lower than the conventional methods. For a gas bubble with ultrasonic wave reflection time from its surface, the simulation results show that the spatial imaging error (SIE) factor is less than 2%.

Non-invasive imaging of liquid/gas flow using ultrasonic transmission-mode tomography

Sensors and Actuators A: Physical, 2007

This paper details the development of non-invasive ultrasonic tomography for imaging liquid and gas flow. Transmission-mode approach has been used for sensing the liquid/gas two-phase flow, which is a kind of strongly inhomogeneous medium. A 16-pair of ultrasonic sensors have been used. By using low excitation voltage of 20 V, fan-shape beam ultrasonic transmitters will emit ultrasonic pulses to the receivers. The investigations were based on the transmission and the reception of ultrasonic sensors that were mounted circularly on the surface of experimental vessel. The algorithms used to reconstruct the concentration profile for two-phase flow using fan-shape beam scanning geometry were presented. By using Hybrid-Binary Reconstruction algorithm (HBR), a real-time of ultrasonic transmission-mode tomography had been developed. Experiments showed that the performance is acceptable with the image reconstruction speed of ten frames per second. The results of the experiments and possible future improvements were also discussed.

Zernike ultrasonic tomography for fluid velocity imaging based on pipeline intrusive time-of-flight measurements

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2014

In this paper we propose a novel Ultrasonic Tomography method for pipeline flow field imaging, based on Zernike polynomial series. Having intrusive multipath time-offlight ultrasonic measurements (difference in flight time and speed of ultrasound) at the input, we provide at the output tomograms of the fluid velocity components (axial, radial and orthoradial velocity). Principally, by representing these velocities as Zernike polynomial series, we reduce the tomography problem to an ill-posed problem of finding the coefficients of the series, relying on the acquired ultrasonic measurements. Thereupon, this problem is treated by applying comparatively the Tikhonov regularization and the Quadratically constrained 1 minimization. In order to enhance the comparative analysis, we additionally introduce sparsity, by employing the SVD based filtering in selecting Zernike polynomials which are to be included in the series. The first approach -Tikhonov regularization without filtering, imposes as the most suitable one. The performances are quantitatively tested by considering a residual norm and by estimating the flow using the axial velocity tomogram. Finally, the obtained results show the relative residual norm and the error in flow estimation, respectively, ∼ 0.3% and ∼ 1.6% for the less turbulent flow and, ∼ 0.5% and ∼ 1.8% for the turbulent one. Additionally, a qualitative validation is performed by proximate matching of the derived tomograms with a flow physical model.

Ultrasonic tomography of nonmixing fluid flows

Physics of Wave Phenomena, 2015

An ultrasonic method for simultaneous measurement of two-dimensional distributions of compositions and flow velocities in a system of two nonmixing fluids is proposed and implemented. The method is based on tomographic reconstruction of images of scalar and vector objects using a rectangular system of stationary transceivers. Images of simple objects (a vortex in a homogeneous fluid and a standing gravitational-capillary wave in a system of two nonmixing fluids) are obtained by this method.

Ultrasonic Tomography–Image Reconstruction Algorithms

This paper focuses on image reconstruction algorithms for use in ultrasonic tomography. There are three types of algorithms namely Linear Back Projection, Hybrid Reconstruction and Hybrid Binary Reconstruction that are of interest. The algorithms have been evaluated on ultrasonic tomography system based on several known phantoms and real objects. The performance of the algorithms have been analyzed and discussed at the end of the paper. A recommendation of suitable reconstruction algorithm for liquid/gas flows has also been made at the end of the paper.

Image Reconstruction Methods for Ultrasonic Transmission Mode Tomography in Bubbly Flow Regime

Image reconstruction from projections plays an important role in monitoring flow regimes by ultrasonic transmission mode tomography (UTMT) system. Fast and more accurate methods are necessary in case of on-line process e.g. bubbly flow regimes. In this work, analytical image reconstruction methods such as linear back projection (LBP), filter back projection (FBP) and convolution back projection (CBP) in bubbly flow regime is investigated and found that CBP is superior to other methods. Furthermore, different filters were applied to CBP to investigate the image quality improvement. Among different types of filters for CBP method, Ram-lack outperforms the others for UTMT. The peak signal to noise ratio (PSNR) of reconstructed images in this particular experiment was improved using Ram-lack in noiseless data.