Green Aero Propulsion Private Limited has conducted a test firing of a sub-kiloNewton (sub-kN) liquid-fuelled aero engine incorporating airblast atomiser technology, the company’s founder and chief executive officer Prithwish Kundu said. The engine is designed to power high-speed drones, Collaborative Combat Aircraft (CCAs), and standoff systems.
Kundu said the engine was recently demonstrated in a long-endurance run during which it reached idle before ramping up to higher thrust. The company said the test validated multiple subsystems including turbomachinery, fuel injection, ignition systems, rotor dynamics, lubrication and metallurgy.
The propulsion system operates on multiple fuels, including jet fuel and diesel, and features an electric start system. According to the company, the engine incorporates advanced airblast atomisers that use high-velocity air to atomise fuel, enabling stable combustion across different fuels.
Green Aero said the engine features a compressor and diffuser configuration developed in-house, along with an effusion-cooled combustion liner designed with microscopic perforations that create a thin cooling film to protect engine materials from high temperatures. The design also incorporates straight internal flow paths intended to minimise pressure drop during operation.
The company said the propulsion unit is manufactured using metal additive manufacturing with superalloys. The approach allows complex internal geometries and monolithic structures to be produced as single components, reducing part counts by nearly 70 percent compared with traditional machining.
The engine operates in the sub-kN thrust category targeting the 20 kilogram-force to 100 kilogram-force segment. The company said this thrust class is intended for high-speed drones, Collaborative Combat Aircraft and loitering munition platforms.
Green Aero has developed a hydrogen-capable aero-engine core known as “Blue Dragon”. The company said the design uses similar thermal management technologies and is intended to support fuel flexibility between conventional aviation fuels and hydrogen.
In July 2025, the company raised USD 1.6 million in a seed funding round led by pi Ventures with participation from Antler. The startup had previously raised about USD 240,000 in late 2024 led by Rebalance and received a grant from Boeing to support early testing activities.
Green Aero said it is establishing a dedicated propulsion test cell capable of simulating high-altitude operating conditions. The company is also recruiting engineers in turbomachinery design, computational fluid dynamics, combustion modelling and embedded systems to support the development of engine control software and propulsion systems.
Founded in 2023 by propulsion scientist Prithwish Kundu, Green Aero Propulsion Private Limited is a Delhi-based aerospace startup focused on developing indigenous aero-engine technologies for defence and civilian aviation applications. Kundu previously worked as a research scientist at Argonne National Laboratory in the United States, where his work included computational fluid dynamics and advanced combustion systems.
