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Geoff_H

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Everything posted by Geoff_H

  1. Geoff_H
    We will have blackouts. Liddell was commissioned in 1971 designed for 20 life. In 1988 I led a team to work out what we needed to do to extend life to 2004. Most was done. But I am surprised that it is running at all. But when it comes to an end the price of electricity will increase. Gas will fill the hole. When coal plant keeps falling over and all the gas plant is operating then any system failure will result in blackouts. Look at the formation of the electricity commission of NSW history. We are back to where it was in mid 1950's. I have just overhauled my little generator.
  2. Geoff_H
    I worked for the electricity commission of NSW and in the early 1970' we looked into going nuclear with a power station built on federal land in Jervis bay. It was not economic then. The cost of a power station consists of the cost of money to build it, the cost of fuel and the cost of labour to maintain it. Coal is medium for interest low for fuel and medium for labour. Nuclear costs at least 10x a coal station. With 70's interest rates far from low interest was enormous, fuel is quite low and labour was high. Just not worth building. These days interest is low. We should do it. The eastern Australian grid would only produce 5 44gallon drums of waste per year.
  3. Geoff_H
    Say that to an engineer at Eraring or Bayswater power stations. They have been designed to come on Quickly and go up in very fast time. I commissioned one of the systems. There is so much BS out there that is put out with a political agenda. Greatest of all is the two most CO2 emitting countries are Indonesia and Brazil. Land clearing! In 2008 when I had a contract with a big mining company to investigate renewable energy I discovered this. One eyed climate change obsessed people usually deny it. Politically impossible to change those emissions. In 2008 land clearing emitted more CO2 each year than all the aircraft that had ever flown since the Wright brothers took off
  4. Geoff_H
    I will have to look it up again. I will get back to you. It is a government site on power and emissions in Australia. It is interesting that the 2019 average nbulk purchase price of electricity was $0.14/kWh. I pay a lot more than that to get it into my house.y
  5. Geoff_H
    People will say that they have solar cells that charge their Tesla so they don't cause any emissions. One 300watt solar panel will generate, on a sunny day, enough energy for a Tesla to travel 4km. So your Tesla has to be in your garage or you need storage batteries at your house to transfer the energy. These batteries and inverters are expensive. But even if you do charge your Tesla using solar cells you only reduce the emissions of CO2 if the solar cells are dedicated to your car. If you are using solar cells that are connected to the grid then while you are charging your Tesla the power that was being injected into the grid has to be generated by some other source, the only other source that allows variation is coal or gas fired generators. So the emissions of CO2 don't change. Solar cells for your Tesla don't reduce emissions.
  6. Geoff_H
    My petrol fuelled BMW 330i creates less CO2 emissions than a Model S Tesla. I expect that this is also true for petrol engined vehicles that have dual cycle engines, many vehicles for sale today. Tesla charge with power from the eastern Australian grid. The grid hass a high emissions per kilowatt hour generated. Basically owing to the use of coal for power generation. The Tesla in NSW generates 0.164kg/km of CO2, the BMW generates 0.147kg/km of CO2. If this is so then why are Tesla's so successful around the world? As an example I examined the New York grid. It is approximately the same side as the Eastern Australian Grid. New York emissions of CO2 are approximately 1/4 of ours. Is used hydro (Niagara Falls) gas (mostly combined cycle) and Nuclear ( 3 Mile Island). Approximately 1/3 of each. Tesla vehicles in New York state emit 1/4 when charged of their grid, and emit far less CO2 than a BMW 330i driving around New York state.
  7. Geoff_H
    Please quote your source of both figures. Particularly the coal cost does not correlate with delivered cost of retail supply costs according to the official website
  8. Geoff_H
    What happened was that he glued the fabric to the timber. Unfortunately most of the glue soaked into the timber leaving a very small amount of glue holding the fabric. The fabric parted from the timber and all aerodynamic shape was lost. I now paint any timber with epoxy, let that cure, sand timber back to smooth then glue attachment to the timber.
  9. Geoff_H
    Bose. They fixed them for free when I have had an problems with the 2 I have over 10 years
  10. Geoff_H
    Residual oxygen on a gas turbine is about 16%. Excess air is used to keep the tit within its maximum temperature range. If you put another burner in the has stream coming out of the first stage turbine and take advantage of the 16% oxygen and reduced temperature of this has stream then burn additional fuel to bring the second row blades up to the same as the first stage you get additional power from the turbine without any extra compressor load. As compressors can amount to around 40% of turbine load this is a considerable advantage. Only big units have been made for stationary applications. I will look it up and post shortly. I worked for Siemens in Florida in the mid 1990s designing 186MW machines when ABB first designed these GTs. They sold them off their design, the machines were good but didn't meet the theoretical design. The liquidated damages sent ABB very close to the wall. Siemens jumped in bailed them out and got the design.
  11. Geoff_H
    I have worked with the trent engine range listed in the brake fuel efficiency stated above. Great engine with multiple shafts. Their are a range of Trent's. The one I worked with was a stationary derivative of the Airbus 380 engines. They have just made a Trent 1000, Rolls Royce have been testing it using renewable style energy fuels. The article leaves out the ABB come Siemens Multiple burner turbine. Much better efficiency.
  12. Geoff_H
    I have thought that the dual cycle cycle piston engines offer better hope. , Mercedes get 400hp from a 2litre engine with quite high efficiency, around same as cheaper GT designns.
  13. Geoff_H
    "Another key feature is that WW2 piston aviation engine efficiencies still beat the best very best turbine engines. I occasionally wonder what they could do with modern injectors and turbocharger technology." GE have produced a 50+% efficient engine. Admittedly it had inlet cooling, water injection and steam cooling of the inlet....stationary engine too heavy to fly lol
  14. Geoff_H
    . Directions YBRL Borroloola Airport NT Landing $23.6363 per tonne, minimum $68.18 Does this fee promote safe aircraft operation. It is unattended with surveillance cameras. It promotes pilots not giving circuit calls. I left Cessnock as aircraft would come from out of the blue, no calls, fees are quite high.
  15. Geoff_H
    That aircraft designed and made in regional Victoria had an undercarriage test device to prove the design. They made a machine that automatically raised the undercarriage connected to a weight, which I expect was the aircraft AUW, and then dropped the weight and landing gear. Don't know what results they got but it seemed a great testing device.
  16. Geoff_H
    Agreed. It was late and I was tired. I mixed metric and ft.......I did leave a caveat that it might be wrong. Thanks for the assistance.
  17. Geoff_H
    I think FAR23 requirement for certified aircraft is a downward velocity of 20 ft/second must be able to be absorbed and still be usable. Have to look up height to give that height but if I recall my high school physics it is 20ft, don't assume that this is correct
  18. Geoff_H
    Maybe there are some political websites where American politics would be better discussed.
  19. Geoff_H
    The French plans for a Cri Cri have both inch and metre dimensions. All inch are decimal. My lathe has both inch and mm calibration. I use both but prefer metric. When my daughter first went to school in Plano TX she was asked how many inches in a mile. This was an American intelligence test. They said that she was just an ordinary student not know such basic stuff. 3 years later aged 14 she had completed all high school mathematics and if we had stayed they would have bussed her to a university to continue her maths. She now has a PhD. I asked her when she used the English system which she preferred. She just looked at me as though I was stupid..."metric she replied". I must add that all science is taught in Texas in metric, maybe all of USA but I am not sure.
  20. Geoff_H
    The Americans call it the English system. When I worked in Texas we had an engineer that would always convert English/imperial system to metric system, do all calculations in metric then convert results to English/ imperial system. Claimed it was easier.
  21. Geoff_H
    Should be calcs not cakes
  22. Geoff_H
    Vertical loads that are supported on the ground had no trouble whatsoever to even a small slab full stop the problem arises when you lose support underneath the slab and it becomes a cantilevered beam. If this happens you can easily crack the slab this is what usually cracks slabs. I find it when I go to a structural engineer and force him to show me his cakes so he's not over designing it that I save a lot of money in steel
  23. Geoff_H
    Sorry my advice is consult an engineer. The edge support or restraint will determine what shear needs to be resisted at edges. I am a mechanical engineer and I always consult a civil/ geotechnical engineer on design. The thing that will trash the job in a few years are the assumptions that are made. An engineer with experience will guard against making an assumption that this slab is just like one seen on the other side of Australia. Best to find an engineer that works on structures near where your hangar will be built. Don't put pads under the slab unless specifically designed and built correctly. They can actually make the slab weaker
  24. Geoff_H
    Sorry my advice is consult an engineer. The edge support or restraint will determine what shear needs to be resisted at edges. I am a mechanical engineer and I always consult a civil/ geotechnical engineer on design. The thing that will trash the job in a few years are the assumptions that are made. An engineer with experience will guard against making an assumption that this slab is just like one seen on the other side of Australia. Best to find an engineer that works on structures near where your hangar will be built.
  25. Geoff_H
    Maximum weight is 7ton. Pressure on concrete would be the tyre pressure. Only problem is bending moment from ground under the concrete not fully supporting the concrete. Tale the 7 tonne point loading ( actually less when shared between wheels) to a civil engineer or geotechnical engineer. He/she will probably tell you off the top of his head if he knows where the hangar is to be built ( they have charts about ground support capabilities).
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