THE VLB ENGINE COMBUSTION CYCLE

With reference to the "half.gif" sketch.

As the super-light piston descends, accelerating smoothly (with a sinusoidal velocity curve) up to maximum velocity at the half stroke point, the air which has entered the lower chamber via the VECTIS system becomes trapped, and then further compressed (supercharged) buffering the piston's descent, whilst both cooling it and significantly damping any tendency towards instability. As the piston clears the transfer chamber's exit, the exhaust valve opens, allowing the spent gas to escape from the top of the cylinder, and the new clean air to enter the cylinder via the transfer channel. (Note that the transfer time, as a percentage of the cycle, is extended by the linear to rotary converter).

Whilst the timing of the air transfer is fixed, relative to the cycle, the hydraulic or pneumatic exhaust valve is not, being directly controlled by the ECU so as to optimise the transfer both in terms of determining the ultimate degree of compression, and also, critically, to avoid resonance within the moving assembly.

After changing direction, the piston then accelerates back to the mid-point, then decelerates to TDC, raising the pressure until the injector's 'motor' plate yields and is progressively driven into its chamber. This forces hydraulic fluid to drive the inject piston, delivering a fuel 'charge' into the cylinder. Back pressure and transfer control, both 'adjusted' by the ECU, ensures that whilst the initially delivered fuel mixes with the chamber gasses, the last drop is delivered just as the chamber enters the adiabatic 'zone'. Then the plugs issue their 'arcs', igniting the local fuel, which in turn further raises the pressure so that it crosses the adiabatic flash-point of the remaining fuel, effecting a (chemically genuine) 'spontaneous' reaction.

The fuel distribution (at least as good as with any conventional injector) in a significant excess of air, ensures that the fuel molecules 'pair' with the oxygen they need under near ideal conditions, and during the initial descent of the piston. Thus (unlike conventional engines) none of the forces generated by the reaction are allowed to oppose the desired piston direction.

The substantial amount of excess air not involved in the chemical reaction, helps to absorb some of the energy, significantly lessening the shock, which would otherwise be directed at the piston. And so the piston is driven on down, recovering much of the stored energy from the air, until the exhaust vlave is opened and the air inlet port is once again exposed.

NOTES

1. The spontaneous reaction (being the state where all of the interactive molecules begin their process at the same time, and not as is sometimes thought an instantaneous reaction) is significantly faster than any other form of combustion. So fast, that without the considerable excess of air, much energy would be lost to heat.

2. In order to maximise the energy conversion, the VLB engine achieves significantly faster piston velocities. At these velocities, the harmonically stable 'sinusoidal' velocity curve becomes essential.

3. The adiabatic 'zone' is a period of the cycle when the pressure/temperature of the gas/fuel mixture is below the adiabatic threshold, but close enough to ensure that this threshold will be crossed by the added pressure resulting from the burning of the fuel trapped in the igniter cusps. This period is significantly extended (as compared with the conventional crank / con-rod / piston) by the sinusoidal linear-to-rotary converter. I know that to many, this sounds like a rather too 'critical' aspect, to be incorporated into a mass-produced engine. However, it is actually very easy to achieve, and very easy to control, it all depends on how it's done.

4. The fuel as delivered to the injectors is 'tailored' such that both its calorific value and its initial flashpoint are dynamically varied to suit engine speed and load.