Description

In this project, a 3D AK-47 in a rectangular domain is designed while the bullet’s velocity is 700 m/s. The compressibility of the air over the bullet is modeled using the High Speed (Compressible) Wall Heat Transfer Model option.

Also, Ideal Air Gas is defined as the material of the solution.

SpaceClaim software is used to create the geometry of the solution. ANSYS Meshing software is used for generating meshes, and the elements are all triangles (unstructured). Plus, the number of elements is 3,236,698.

Methodology: AK-47 Bullet Movement

The High Speed (Compressible) Wall Heat Transfer Model option is enabled due to the compressibility of the working flow. The speed of the bullet is 700m/sec which is exactly equal to the Mach number of 2.04082.

That’s a good reason for us to select the ideal gas option for the density of the air to model its compressibility. The gravitational acceleration effects are ignored.

Conclusion

At the end of the solution process, two-dimensional contours of pressure, temperature, and velocity are obtained.

As it can be seen in the figures, the shock waves around the bullet are propagated. A shockwave is generated when a wave propagates through a medium at a speed faster than the speed of sound travels through that medium. Shockwaves produce an abrupt spike in pressure over a very short time period.
The mentioned shockwave is visible in the Density, Velocity, Pressure, Temperature and Mach number contours.

Also the distribution of static pressure on the surface of the bullet is shown in the contours.