Computational method for shock reflection


The respected Comrade Kim Jong Un said:

"The basic sciences are the cornerstone of a sci-tech power. A high level of basic sciences enables a country's science and technology to make steady progress on a solid foundation."

The phenomena of shock reflection and interference appear mainly around various bodies in supersonic flow and it is one of the important problems for resolving the flow characteristics to establish an exact computational method for them.

The Faculty of Mechanics of Kim Il Sung University have performed a research for computing the characteristics of shock reflection that can be found in different supersonic flows.

So far, the scientific research institutions in the country have studied the flow with shock wave using the traditional analytical method such as the characteristic method or common software, but they have proposed few computational method considering different special cases including shock reflection. For example, there are usually two shock waves, the incident shock wave and reflected shock wave when the shock wave is reflected. However, if the incident angle is larger than some angle or within some Mach numbers, a new shock wave appears and there exists three shock waves. In this case, the novel computational methods are needed for the research.

There are some doubts how to study this special case over the world and several methods have been proposed from a long time ago. It can be mainly divided into two kinds with the direction of this study.

First, the shock reflection is divided into the regular reflection with two shock waves and the irregular reflection with three shock waves. Then the condition of the transition between regular reflection and irregular reflection is to consider.

Next, the characteristics of a new shock wave in irregular reflection is to consider.

The faculty set up the issue to study the characteristics of a new shock wave in irregular reflection and proposed a computational method.

First of all, we have proposed certain assumptions for a new shock wave and computational method for predicting the several characteristics such as the height of it.

Also, we have confirmed the validation of the computational method through the comparison with the previous experimental and theoretical results.

The new computational method for shock reflection is a good method that has synthesized the existing theoretical research results and studied a special case of shock reflection.

The scientific significance is to study the shock wave reflection phenomena including the new characteristics of shock wave that have not been considered so far.

The great success is expected in this field because the new computational method of shock wave reflection is one of the basic and important problems that should be considered in the design and motion analysis of various bodies.

These results were published in "Proc IMechE Part G: J Aerospace Engineering" under the title of "A method for predicting Mach stem height in steady flows"(