Ray-tracing simulation of sound drift effect for multi-path ultrasonic high-velocity gas flow metering

Robust, fast and reliable examination of the surroundings is essential for further advancements in autonomous driving and robotics. Time-of-Flight (ToF) camera sensors are a key technology to measure surrounding objects and their distances on a pixel basis in real-time. Environmental effects, like rain in front of the sensor, can influence the distance accuracy of the sensor. Here we use an optical ray-tracing based procedure to examine the rain effect on the ToF image. Simulation results are presented for experimental rain droplet distributions, characteristic of intense rainfall at rates of 25 mm/h and 100 mm/h. The ray-tracing based simulation data and results serve as an input for developing and testing rain signal suppression strategies.

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Simple and Exact Closed-Form Expression for Determination of a Penetrated Ray Path in a Ray Tracing

International Journal of Antennas and Propagation ◽

10.1155/2013/545874 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Hyun Wook Moon ◽

Woojoong Kim ◽

Sewoong Kwon ◽

Jaeheung Kim ◽

Young Joong Yoon

Keyword(s):

Closed Form ◽

Approximate Method ◽

Ray Tracing ◽

Conventional Method ◽

Closed Form Expression ◽

Indoor Environments ◽

Straight Line ◽

Ray Path ◽

Ray Tracing Simulation

A simple and exact closed-form equation to determine a penetrated ray path in a ray tracing is proposed for an accurate channel prediction in indoor environments. Whereas the penetrated ray path in a conventional ray tracing is treated as a straight line without refraction, the proposed method is able to consider refraction through the wall in the penetrated ray path. Hence, it improves the accuracy in ray tracing simulation. To verify the validation of the proposed method, the simulated results of conventional method, approximate method, and proposed method are compared with the measured results. The comparison shows that the proposed method is in better agreement with the measured results than the conventional method and approximate method, especially in high frequency bands.

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Mass Transfer and Friction in Near-Wall Film Flows in Conditions of High-Velocity Co-Current Gas Flow

Microgravity Science and Technology ◽

10.1007/s12217-009-9149-1 ◽

2009 ◽

Vol 21 (S1) ◽

pp. 277-281 ◽

Cited By ~ 3

Author(s):

Victor Prikhodko ◽

Igor Yarygin ◽

Vyacheslav Yarygin

Keyword(s):

Mass Transfer ◽

High Velocity ◽

Gas Flow ◽

Wall Film ◽

Film Flows ◽

Near Wall

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Coupled Heat and Mass Transfer CFD Model for Methane Hydrate

Volume 10: Petroleum Technology ◽

10.1115/omae2015-42258 ◽

2015 ◽

Author(s):

Eugenio Turco Neto ◽

M. A. Rahman ◽

Syed Imtiaz ◽

Thiago dos Santos Pereira ◽

Fernanda Soares de Sousa

Keyword(s):

Natural Gas ◽

Multiphase Flow ◽

Gas Hydrate ◽

Gas Flow ◽

Three Dimensional ◽

Hydrate Formation ◽

Cfd Model ◽

Flow Metering ◽

Ansys Cfx ◽

Gas Hydrate Formation

The gas hydrates problem has been growing in offshore deep water condition where due to low temperature and high pressure hydrate formation becomes more favorable. Several studies have been done to predict the influence of gas hydrate formation in natural gas flow pipeline. However, the effects of multiphase hydrodynamic properties on hydrate formation are missing in these studies. The use of CFD to simulate gas hydrate formation can overcome this gap. In this study a computational fluid dynamics (CFD) model has been developed for mass, heat and momentum transfer for better understanding natural gas hydrate formation and its migration into the pipelines using ANSYS CFX-14. The problem considered in this study is a three-dimensional multiphase-flow model based on Simon Lo (2003) study, which considered the oil-dominant flow in a pipeline with hydrate formation around water droplets dispersed into the oil phase. The results obtained in this study will be useful in designing a multiphase flow metering and a pump to overcome the pressure drop caused by hydrate formation in multiphase petroleum production.

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