@3bod: Thanks for your interest; greatly appreciated. I had a long conversation with John Popovich this afternoon. He said while he is busy drawing charts and graphs for publication in a few Tech journals and lacks the time to type out explanations on the internet, for any who have read the PDF file and have specific questions, just give him a call. His number is listed at the bottom of his web page, and will be happy to explain how conservation of momentum comes into play here, along with how high pressure is effectively replaced by heat regeneration ratios and parallel processing. Sorry I can’t do better than this for now, but I need to spend some doing some advanced google and wiki-searches before I can feel comfortable relaying his thoughts.
I should mention my experience with the inventor goes back to 1965 at UCLA. It was the annual meeting of the International Solar Energy Society, (ISES) and an engineer I knew from San Diego Gas and Electric’s Solar Division told me he had just seen the future of flat plate collectors and dragged me to JP’s booth. I won’t go into details, but at a much later workshop I conducted on testing collectors with ERDA funding, I saw him convince the crème of the radiation physics docs in solar just how many things they had missed in developing their standards. Give him a call. I think you’ll be blown away.
Hmm, i'm curious what the overall gain is then? I mean, producing smaller/cheaper units is one thing, but if these units are not at least as efficient as normal ones, i don't see any gain in the long run.
Let me give an exaggerated example:
You build a turbine for half the cost & somewhat smaller size than regular ones. But that sucker needs twice as much fuel to do the same work. Sure, initially you are cheaper. But in the long run, you pay much more because of the increased fuel consumption.
So, i think that numbers about efficiency are quite important here. Just reducing the unit cost is only a very short term benefit. Once the fuel and operating costs kick in, you have to consider these factors as well.
Greetings,
Chris
@Chris: Yo dude! Really miss reading your hilarious comments on the ddwfttw thread here, and sure wish you’d rejoin the fun at TR-just use the link in my sig and check it out. JB and spork will be showing an enormous, drivable cart to NALSA out in Nevada next week to see what will be required to test it. Great suspense, with lots of videos and more to come.
As to your question, what if your cost was less than half and efficiency a very small percentage lower? Not saying that’s the case, as John believes the efficiency will in many cases exceed existing turbines. Do read the PDF carefully. It’s long I know, but I believe it will answer most of your questions. Hope what I’ve posted below from the PDF will fuel your interest. There are aspects of this similar to the angular momentum of spork’s cart. Hope this helps, and thanks for your interest.
"Efficiency: efficiency decreases generally with decreasing scale but the loss mechanisms associated with scale reduction can be mitigated in XpoTurbine engine design. Engine efficiency can be increased by increasing the pressure and temperature ratios. XpoTurbines can be designed to operate with a wide range of pressure and temperature ratios, but there is another possible avenue of design that allows high efficiency without high‐pressure temperature ratios. The XpoTurbine engines described pursue this avenue.
Thermally regenerative Brayton cycle engines INCREASE in efficiency with decreasing pressure ratio and this allows reduced component mass, stress, and cost.
Thermal regeneration in XpoTurbines is provided by intake and exhaust flow heat exchange and by exhaust gas recirculation. Engine efficiency returns diminish with increasing temperature ratios and the material costs and heat
losses increase. High pressure ratios also cause the air entering the combustion region to be at a high temperature from compression and the temperature rise from combustion must be added to this. Xpoturbines can use low pressure ratios and catalytic combustion to reduce the maximum temperature and thereby reduce component stresses, component costs, and heat losses.
Assuming an ambient temperature of 300°K and a 300°K temperature rise to 600°K the theoretical maximum efficiency is 50% (600°K‐300°K/600°K=0.5) and the proportion of the theoretical efficiency realized can be higher than would be the case with higher maximum operating temperatures because the heat losses Fare less and the choice of materials and processes used in construction allow further heat loss reductions. Reduced operating temperatures, vacuum insulation and low emission surfaces also allow Xpoturbines to be more easily incorporated into consumer products.
Controlled porosity passages: The degree of shear force usage can be varied by the incorporation of porous elements which can be used to exchange work between the fluid and the rotor, increase surface area for heat exchange, enhance mixing, provide catalyst support, act as flameholder, and provide structural communication. Planar wire cloth (screen) rotors with intake and exhaust flows in the plane of the screen can be used to provide a large heat transfer area in a compact system. (S Fi See Fig.11) Porous passage walls normal to the plane of the system may be of spiral form and may be made to lead or lag the flow spiral pattern that would be created by the enclosure surfaces without walls. On the compressor side where the
rotor velocity exceeds the flow velocity and the rotor is transporting work to the fluid, the spiral/s may be “faster” than the unimpeded flow path and thereby increase outward forces.
Controlled porosity elements can be used to divide the flow stream into a large population of small streams and thereby reduce the diffusion path length for heat and mass transport and the consequent time required for mixing, heat transport, catalysis, and combustion.
Consider an engine with an entry cross‐sectional area of 1cm2 (0.2cmX5cm) and 20 passage walls of spiral form, each with a porous catalyst region near the perimeter of 0.2cm in height X 2.5cm in length for a total cross‐sectional area of 0.2X2.5X20=10cm2. If the passage walls are composed of stainless steel wire cloth with 20 wires per/cm spacing in the warp and woof axis, 0.014cm diameter wire, and 50% open area, the flow cross‐sectional area will be increased by a factor of 5 and the number of flow passages will be increased to 4000 (20X20X10cm=4000). Further increase in cross‐sectional area is possible by corrugating the porous walls in this region. The flow will also be reduced in velocity in proportion to the radius ratio between the inlet radius and the local radius at the passage wall divided by the increase in the temperature ratio. The division of the flow into a large population of small flows allows combustion to take place in a very short time period, as diffusion of heat and mass is proportional to the square of the travel distance (l2). Copper or stainless steel screens can be nickel plated and further plated/coated by catalyst media such as Palladium for methane combustion or Platinum for propane combustion. (See Fig.3)
Porous elements can also provide structural communication, prevent dissipative secondary flows by energizing boundary layers, and reduce the drag associated with heat and mass transport processes. Wire cloth used to mfr passage walls can be bias cut at 45 degrees to minimize edge effects associated with processing and to reduce drag by presenting more optimal passage form to the flow. The wire cloth can then be selectively plastically deformed by pressing or rolling to reduce warping and to vary porosity.
