New revolution in prime mover technology
RVCR mechanism, the next progressive mutation in machine mechanism, leads to a new generation of multi-fuel engines.
The automotive sector today is focused on electric drive and has caught the attention of the public. But there is a catch 22 type dilemma here. If the oil consumption is reduced by electric engines and oil production continues, oil will become cheaper owing to less demand and excess supply. The battery technology will have to compete with cheaper fossil fuel making it economically unviable. The electric alternative to the existing powertrain systems is limited to automotive which is only a fraction of the powertrain applications and is not applicable to the entire bulk of industrial and commercial applications where the fuel driven prime mover (engine) is used, (as in heavy commercial vehicles; material handling, mining,
earth moving equipments, defence applications like tanks, armoured vehicles, aviation (UAV’s to helicopters), marine propulsion (boats, ferries, ships), large power generation units etc. The significance of engines to industry remains. Unhooking of fossil fuel dependency is not as simple as switching to electric cars, rather it is a transition to technological solutions for greener alternatives. It is this challenge that a new revolutionary ‘RVCR technology’, based on an invention in engine kinematics by an Indian engineer and inventor Das Ajee Kamath.
Conventional engine vs RVCR Technology: RVCR is a seedmachine kinematics that has various downstream applications in engines, renewable energy power generators and utility machines. RVCR enables a feature called ‘VCR’ (Variable Compression Ratio) which specially revolutionises engines. RVCR is a leap in technology compared to conventional engines and differs in the very makeup of the way engines work.
The rarity of the RVCR system can be gauged by the fact that in the last 150 years only 3 systems have come into existence namely (1) ‘Reciprocating piston and crank mechanism’ used in 90% of engine applications, including land and marine transport; (2) the ‘Turbojet’ used in aviation, (3) the ‘Wankel rotary’ used in a few other applications. The three systems have served humanity well. However, they have a common limitation. The ‘Compression Ratio’ (CR) of these engines cannot be changed. Varying of CR allows engines to switch fuels while in operation from petrol to diesel to CNG etc. Further VCR also improves fuel efficiency by 27% to 30%.
Though the global industry majors have struggled with VCR engines for over half a century with various VCR engine models, they are still confined to test beds due to extreme the complexity in making any of them commercially unviable. These VCR test models have proved the benefits of VCR in reducing fuel consumption and emissions.
RVCR implications: RVCR mechanism the 4th addition in engine kinematics allows realtime VCR to swap fuels. Hence the same engine can use both petrol and diesel (S.I or C.I fuels). The system opens doors to the use of choice of fuels ranging for lightfast burning CNG, LPG, petrol, and heavier fuels like diesel and bunker oil. It can adapt the compression ratio while in operation to the fuel used, including bio-fuels. Hence providing a unified platform for transition from fossil fuel to green
fuel does-not conflict with the current oil-based economy.
About RVCR: RVCR uses rotary pistons inside a hollow torus thus avoiding the complications of reciprocating pistons. This eliminates the bore stroke ratio limitations which allows rapid expansion of fuel at slow speeds and does not require engines rpm to be high as in conventional engine. Other benefits include downsizing; maximum mechanical leverage throughout the gas expansion process; elimination of reversing of inertia forces and 2nd order vibrations etc.
RVCR Status: The RVCR technology is completely developed in India and is patented in 49 countries and has been assessed at the highest international platforms. RVCR Project was the winner of IIGP 13 by Lockheed Martin, DST and GCIP 14. The scientific and engineering challenge to realise an engine for powertrain systems is a mammoth task. It can be gauged from the fact that though I C engines have existed for over 125 years, their design and development remains in the domain of the western world companies. In India many companies do manufacture engines for automotive and slightly larger applications, however the designs are either procured from western sources or are made by peripheral modifications to the existing design. When it comes to larger engines it is a complete dependency on imports.
Considering the limitations for the execution of a prime mover design project in India and the lack of funding, the inventor shifted his base to the UK where he has gained Phase-I funding from Horizon 2020 scheme of the European Commission. The inventor has made many attempts with the government of India for facilitation of the project that can relieve India from technology dependency on imports in prime movers for defence and maritime operations and to open doors to the $ 500 billion global engines market. However, the lack of support structure for breakthrough technologies and of any precedence in handling greenfield technology project of such scale has been the main bottleneck.
The technology: The RVCR mechanism is the next progressive mutation in machine mechanism and leads to a new generation of highly efficient multi-fuel engines for the 21st century environmental demands.
The new RVCR technology is about two curved pistons that snuggly fit inside a hollow torus (doughnut shape) chamber and are free to rotate independently. When one piston rotates the other is kept stationary and compresses the air ahead of the rotating piston. Here the rotating piston is clutched to a shaft passing through the central axis of the doughnut through and through.
As the piston rotates and nears the stationary piston it is made to actuate a switch just before it could collide with the stationary piston. The switch actuation signals the stationary piston to engage with the central shaft and rotate along with the other rotating piston. This is an equivalent of the slide valve used in a steam engine that opens the steam valve to push it back in the opposite direction. Here the switch actuates the stationary piston to couple with the central shaft and start rotating synchronously along with the rotating piston and avoid being stuck by the rotating piston. Similarly, as the stationary piston starts rotating, it actuates a switch just ahead of it that decouples the previously rotating piston from the rotating shaft and brakes it at the same stationary point where the previously stationary piston was held.
The position of the switch dictates the gap between the two pistons and hence the compression ratio. As the rotating piston reduces the gap with the stationary piston the air trapped between them is compressed and the degree of compression increases as the gap decreases.
The RVCR technology allows engines to achieve analogous variation in the compression ratio by sliding the switch position relative to the piston and hence a piston could actuate the switch either when it is very close to the stationary piston or at a considerable distance from the stationary piston. Furthermore, the dynamic real-time setting of the compression ratio within the load range (from idling to full load) enables the RVCR engine to deliver the highest possible efficiency for every individual fuel used. It controls emissions for any power or load condition by adapting compression ratio to lower combustion temperatures.
Das Ajee Kamath, Chairman and Managing Director, Gyatk