Integrated Shock Sensor Accurately Dissipates Harmful Waves

When a fighter jet rapidly ascends and speeds up forward, a sonic boom resonates across the surface of the jet and through the surrounding sound waves. At the very most, it is disgusting noise pollution. In the worst case, it can cause damage to the aircraft’s surface.

It is very tough to diffuse this shock wave since conventional techniques tend to offer either precision or efficiency, but not both.

At present, scientists from Yokohama National University in Japan have created an integrated shock sensor to accurately and rapidly dissipate detrimental shock waves. The study outcomes were reported in the Journal of Computational Physics on July 4^th, 2019.

There’s a growing need for a simple and accurate shock-detection method in computational fluid dynamics.

Keiichi Kitamura, Associate Professor of Engineering, Yokohama National University

However, researchers do not intend to remove shocks completely—not all shocks are harmful, after all.

If a shock wave is applied accurately, it flows via kidney stones and crumbles the calcified rocks to render them easier for a person to pass. This process needs considerably more accuracy to prevent healthy tissue from being damaged; however, it could be time-consuming.

Shock has been applied to the medical field through Extracorporeal Shock Wave Lithotripsy. It’s one of the most common treatments for kidney stones in the United States of America. But most of the conventional shock-proofing methods are designed to satisfy only accuracy or efficiency.

Keiichi Kitamura, Associate Professor of Engineering, Yokohama National University

“In all cases, it is of great importance to identify the exact location of the shock wave quickly,” added Kitamura.

As part of the new research, the team integrated an imaging processing technique with a theory on the anticipated conditions in compressible flow physics—when fluid flow possesses compressible effects, for example, developing a shock wave when the fluid moves more rapid compared to the speed of sound. The shock is caused by this speed.

The researchers modified the imaging processing technique to detect pressure rather than discontinuous variations in the brightness of digital images. This enables them to rapidly observe the shock wave.

Through the integration of the visualized image of the shock with the postulate of the way pressure should bounce across the shock, scientists can precisely estimate how a particular shock wave will behave. The imaging process technique is termed “computationally cheap” Kitamura, as it deals with only the overviews of greatest pressure, instead of making efforts to account for all the variable pressure in the image.

In addition, the scientists compared their technique with conventional sensors to test for accuracy and efficiency: the Ducros sensor and the Kanamori-Suzuki sensor. The Kanamori-Suzuki leverages the flow characteristics theory to sense shock. Moreover, it is famous for its accuracy. The Ducros is extensively used and familiar for its efficiency at low cost.

In our examples, we confirmed that our method is as accurate at the Kanamori-Suzuki method and as cheap as the Ducros sensor.

Keiichi Kitamura, Associate Professor of Engineering, Yokohama National University

At present, the technique is restricted to square cell grids, which is used by the imaging software. Going forward, the researchers intend to expand their technique to be applicable to an extensive array of differently structured grids. This could be used for a range of technologies, such as enhancements to how a jet diffuses shock.

“As this research advances, the shock capturing ability will become more efficient, leading to drastic cost reductions in developing aircraft vehicles and pursuing space developments,” added Kitamura.

Source: https://www.ynu.ac.jp/english/