IIT Hyderabad students build low-cost light gas gun firing supersonic projectiles

HYDERABAD: Seven students from multiple branches at the Indian Institute of Technology Hyderabad (IIT H) have built a low-cost light gas gun that can fire projectiles at supersonic speeds. The prototype projectile, developed using helium and an eight-metre-long barrel, when fired, can travel at speeds of up to 800 metres per second, said a faculty member who mentored the team.

The project was taken up under the BHARATI (Bold Hearted Aspirants Raising to Transform India) initiative, which offers funding and mentoring to first-year BTech students to help them innovate.


The team members said their objective was to develop a gas gun capable of firing faster than the speed of sound, which is 343 metres per second.

Explaining the working principle of the prototype, Pritam Hemant Bagle, a student from the physics department and part of the team said, "The system works by converting the gas's potential energy into kinetic energy, allowing the projectile to reach very high speeds while keeping the pressure low." For this innovation, the team used sanitary-grade PVC pipes sourced from construction yards, which can withstand pressures of up to 30 atmospheres, and 3D-printed projectiles.

"Guns are typically made of metal due to the extremely high pressure inside the barrel — which is usually around 200 atmospheres. However, we decided to use PVC pipes," said Karthick SK, assistant professor of mechanical and aerospace engineering, who is guiding the students. He added: "Using a helium cylinder and compressed gas at 10 atmospheres, in an eight-metre-long barrel, allowed us to accelerate a three-gram bullet to a maximum speed of 800 metres per second."

The team conducted multiple studies to study the velocity of the projectile. They will publish its findings at the seventh national wind tunnel conference at the Birla Institute of Technology, Ranchi, in the third week of February.

The prototype was built on a budget of about Rs 50,000, purely for research purposes, the students said.

"This is a test rig. For example, when a space probe re-enters Earth's orbit, it can collide with debris at supersonic speeds. This system can be used to study the impact of such debris on space probes, as well as how projectiles disintegrate under extreme conditions," said M Raj Kiran Reddy, a PhD student who is part of the project.