As cities worldwide seek quieter and more efficient ways to integrate drones and air taxis into urban environments, a new propulsion concept is emerging that proposes to eliminate exposed propellers and jet engines entirely. Introduced by mechanical engineer and international inventor Mohsen Bahmani, the “distributed reaction” architecture focuses on how thrust is packaged, synchronized, and maintained within a vehicle’s frame.
The Mechanics of Conventional Flight
To understand the potential shift Bahmani’s concept represents, one must first look at how standard drones operate. Modern multirotors, such as quadcopters, rely on the rotational motion of motors and propellers to convert energy into thrust. When these propellers spin, they push air downward—a physical action. According to Newton’s Third Law of Motion, for every action, there is an equal and opposite reaction; in this case, the downward movement of air generates an upward force called lift.
While effective, this conventional method faces significant hurdles for urban integration:
- Noise Pollution: High-pitched noise from spinning rotors is a primary constraint for Urban Air Mobility (UAM), affecting resident comfort and potentially requiring strict new sensory noise standards.
- Energy Limits: Most small multirotors rely on lithium-based batteries, which currently face energy density ceilings that typically limit flight times to significantly less than 40 minutes.
- Safety Concerns: Exposed, fast-spinning blades present inherent risks in crowded city environments.
Internal Motion and Physics
Unlike traditional aircraft that rely on external rotating blades, Bahmani’s design utilizes a closed-loop track containing multiple compact “reaction units,” such as electric impellers. These units circulate through a repeating four-phase cycle:
- Acceleration: Units are energized by sensors and accelerated along the first straight segment of the track, accumulating significant kinetic energy.
- Energy Transfer: As the units pass through a curved section, centrifugal force transfers that energy to the track, creating forward thrust.
- Deceleration: The units are decelerated and controlled by an impeding procedure to manage speed and overcome gravity.
- Return: The units pass through a final curved path at low velocity to return to the starting point and repeat the cycle.
A critical point of the proposal is its adherence to classical physics. Bahmani clarifies that the system is not a “reactionless drive.” To generate net thrust, the architecture must comply with Newton’s third law of motion through momentum exchange with an external medium—typically by accelerating air or another working fluid through a directed internal path.
Wireless Power Integration
One of the primary engineering challenges of any moving modular system is power delivery without the mechanical complexity of physical wires or sliding contacts. To address this, the concept includes an optional wireless power delivery system using electromagnetic induction.
By running high-frequency alternating current (around 1 to 3 MHz) through a wire loop around the track, the system creates a magnetic flux. Secondary coils in the moving impellers then capture this energy through induction, according to Faraday’s Law. This method aims to reduce maintenance and remove common failure points, with reported efficiency reaching up to 90%.
Development and Regional Focus
Bahmani, a graduate of the Karlsruhe Institute of Technology (KIT) in Germany, has previously received international attention for his work in hovercraft technology, including “floating shoes” that allowed for walking on water. His latest propulsion concept has been granted a European patent, marking an initial milestone in its technical validation.
The inventor is currently focusing outreach on the Sacramento region to identify partners for the next stages of research and prototyping. The region’s mix of aerospace supply and engineering talent makes it a practical base for testing and commercialization. The development roadmap for the technology includes several key milestones:
- Bench thrust-to-power testing to measure single-module output on a thrust stand.
- Thermal and duty-cycle evaluation to manage heat during sustained operation.
- Multi-unit synchronization to verify control stability and steady output.
- Closed-loop demonstrator testing to verify mechanical behavior and acoustic signatures.
Future Applications and Market Potential
While the architecture is still in the concept and early-stage development phase, Bahmani suggests that if validated, it could offer significant advantages in noise reduction and system redundancy. Because the system uses smaller, internal impellers rather than wide-span propellers, it may enable slimmer vehicle designs suitable for dense urban environments.
The potential applications for this platform are diverse, extending beyond the drone industry to include the automotive, maritime, railway, and even space sectors. By shifting the focus from individual motor efficiency to overall propulsion architecture—often referred to as Distributed Electric Propulsion (DEP)—Bahmani aims to provide a scalable solution that can be designed for “graceful degradation,” potentially maintaining operation even if a single module fails.
