scholarly journals Simulation of Fluid Dynamics Monitoring Using Ultrasonic Measurements

2021 ◽  
Vol 11 (15) ◽  
pp. 7065
Author(s):  
Masaru Nagaso ◽  
Joseph Moysan ◽  
Christian Lhuillier ◽  
Jean-Philippe Jeannot

The simulation of the propagation of ultrasonic waves in a moving fluid will improve the efficiency of the ultrasonic flow monitoring and that of the in-service monitoring for various reactors in several industries. The most recent simulations are mostly limited to 3D representations of the insonified volume but without really considering the temporal aspect of the flow. The advent of high-performance computing (HPC) now makes it possible to propose the first 4D simulations, with the representation of the inspected medium evolving over time. This work is based on a highly accurate double simulation. A first computational fluid dynamics (CFD) simulation, performed in previous work, described the fluid medium resulting from the mixing of hot jets in a cold opaque fluid. There have been many sensor developments over the years in this domain, as ultrasounds are the only method able to give information in an opaque medium. The correct design of these sensors, as well as the precise and confident analysis of their measurements, will progress with the development of the modeling of wave propagation in such a medium. An important parameter to consider is the flow temperature description, as a temperature gradient in the medium deflects the wave path and may sometimes cause its division. We develop a 4D wave propagation simulation in a very realistic, temporally fluctuating medium. A high-performance simulation is proposed in this work to include an ultrasonic source within the medium and to calculate the wave propagation between a transmitter and a receiver. The analysis of the wave variations shows that this through-transmission setup can track the jet mixing time variations. The steps needed to achieve these results are described using the spectral-element-based numerical tool SPECFEM3D. It is shown that the low-frequency fluctuation of the liquid metal flow can be observed using ultrasonic measurements.

2018 ◽  
Vol 169 ◽  
pp. 01001
Author(s):  
Xiangyang Ye ◽  
Francesco Pisu ◽  
Stephan Grob ◽  
Mahesh Dhotre ◽  
Javier Mantilla

In a high-voltage circuit breaker, the exhaust tube connects the arc zone with the exhaust volume. During the arc interruption process, the exhaust tube transports the hot gas from the arc interruption zone to the exhaust volume through its distributed holes. The design of a high performance exhaust tube in the circuit breaker development aims for well controlled hot gas evacuation mass flow and pressure waves. In this paper, the exhaust tube behaviour is investigated using Computational Fluid Dynamics (CFD). To verify the CFD simulation, a basic experimental study with pressure measurements at different positions of the exhaust tube is performed. Further, the design parameters influencing the exhaust tube behaviour and circuit breaker performance are investigated and discussed.


2021 ◽  
Author(s):  
Jousef Murad

Abstract Computational fluid dynamics is a computational method that enables engineers and designers to study the motion of fluids through computer simulations and modelling. Many tools on the market are so-called “in-house” tools requiring a certain level of expertise and upfront investment before proving their added value. Facilitated by the emergence of cloud computing, computer-aided engineering (CAE) technology is now offered as a software as a service (SaaS) solution, which increases its accessibility and ease of use. Online fluid flow (CFD) simulation is used in addressing a broad variety of problems like electronics design or pedestrian wind comfort (PWC), allowing engineers to accurately predict fluid flow behaviour guiding them towards smarter design decisions. SimScale is creating a paradigm shift for high-performance computing which can solve several problems that are faced when using on-premises software.


Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Edgar V.M. Carrasco ◽  
Rejane C. Alves ◽  
Mônica A. Smits ◽  
Vinnicius D. Pizzol ◽  
Ana Lucia C. Oliveira ◽  
...  

Abstract The non-destructive wave propagation technique is used to estimate the wood’s modulus of elasticity. The propagation speed of ultrasonic waves is influenced by some factors, among them: the type of transducer used in the test, the form of coupling and the sensitivity of the transducers. The objective of the study was to evaluate the influence of the contact pressure of the transducers on the ultrasonic speed. Ninety-eight tests were carried out on specimens of the species Eucalyptus grandis, with dimensions of 120 × 120 × 50 mm. The calibration of the pressure exerted by the transducer was controlled by a pressure gauge using a previously calibrated load cell. The robust statistical analysis allowed to validate the experimental results and to obtain consistent conclusions. The results showed that the wave propagation speed is not influenced by the pressure exerted by the transducer.


Author(s):  
S N A Ahmad Termizi ◽  
C Y Khor ◽  
M A M Nawi ◽  
Nurlela Ahmad ◽  
Muhammad Ikman Ishak ◽  
...  

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.


2013 ◽  
Vol 444-445 ◽  
pp. 1113-1117
Author(s):  
Chong Wang ◽  
Dao Fei Zhu ◽  
Fan Han Liu ◽  
Shi Bo Wang ◽  
Hua Wang

In view of the serious problems that low-rate reduction and excessive oil consumption of reducing oil guns which are used in the depleted EAF, analyzing the jet mixing process through the CFD simulation with the method of liquid level tracking, we find that the purpose of mixing slag layer, guaranteeing matte layer precipitation and saving oil can be achieved by changing combination of gas rate of mixture injected by the oil gun, jet speed and insertion depth. The results of this paper provide a theoretical foundation for optimizing reducing technical process of the slag cleaning furnace operation in a copper industry Company.


2015 ◽  
Vol 1101 ◽  
pp. 471-479
Author(s):  
Georges Freiha ◽  
Hiba Othman ◽  
Michel Owayjan

The study of signals propagation inside porous media is an important field especially in the biomedical research related to compact bones. The purpose of this paper is to determine a mathematical formulation of the global coefficients of transmission and reflection of nondestructive ultrasonic waves in any bi-phase porous medium. Local coefficients of transmission and reflection on the interface of the porous medium will be determined based on a study of boundary conditions. The behavior of different waves inside the porous medium will be developed so that we can derive a new formulation of global coefficients that takes interior phenomena into consideration. Results are found independently of the geometrical and physical characteristics of the medium. Note that this study is based on normal incident ultrasonic wave propagation.


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