Ian

6 minutes ago, Flying Binghi said:

We have a cheaper Av fuel in Oz now. Why rush.

Personally I'd rather see lead phased out as soon as possible. Even relatively small amounts show an impact on children's IQs. https://pubmed.ncbi.nlm.nih.gov/8162884/

Given the choice I'd ban it tomorrow, I think that its continued use is negligent to the point of being criminal. As an industry aviation would deal with it. 

While lead IQ relationships are reasonably easy to measure a more insidious linkage relates to violent crime and antisocial activities. All in all it's a bad news story and a sucking chest wound on the industry.

On 04/09/2022 at 11:39 AM, Old Koreelah said:

My second version is based on a $28 windscreen washer kit. It operates only at full throttle, so I only have to top up the 4 litre tank after several take-offs. It sprays directly into the carby mouth. I’ve gradually increased the spray rate in ground testing until it’s getting more water than fuel. Still hasn’t put out the fire!

Have you noticed any changes at all in the oil or anything else?

From an installation point of view how would you rate the difficulty out of 10? A couple of photos would be nice if you have the time?

Thanks for that, it's good for someone to wrap a bit of analysis on the practicalities.

In reality the only way that this will work is if drop dead dates are set for the phase out of leaded fuel. From an STC point of view does it make more sense to buy one for this fuel or mogas?

On the one hand you will have compatibility across the fleet however it comes with an reasonably pricey STC and higher fuel prices. On the other hand you will have a cheaper and readily available fuel which only covers 80% of the fleet, some of which will require STCs which is about USD $1.50 per HP.

https://www.eaa.org/eaa/pilots/eaa-stc-program/auto-fuel-stc

I watched a presentation by an analyst recently who was of the opinion that we're already in the next cold war and his arguments were somewhat compelling.  If that's the case supply chain security might garner a little more focus from Government. I think that his strongest argument related to the sell off of US treasury bonds by China which significantly reduces the potential for fiscal collateral damage. Of course tea leaf gazing is a difficult business. 

It is a big achievement however it's probably about 20 years too late.

From a value perspective using mogas and water mw50 injection starts to look pretty good. That's 90c in the US which based on the general pattern of pricing means about double over here, and that's an optimistic 90c

With 80% of traditional certified engines having the ability to run on straight mogas it will be interesting to see how it pans out.

All these things are possible as long as they're carbon neutral. But I can't see coal having any redeeming values in the future. The Government has thrown billions in subsidies toward lower emission coal and it's all failed. They could have built a nuclear power plant in the money that they gave away.

1 hour ago, Flying Binghi said:

I made a substantial investment in a biodiesel fuel company over 20 years ago - that were back in my stupid greeny days. All gone

That's the thing about investment, it's all about the timing. As Kerry Packer said, its easy, buy low, sell high. Maybe if we had politicians with a bit of vision pretending that climate change wasn't an issue things may have been different.

If they actually start to make all vehicles carbon neutral maybe engines like this will become back in fashion https://en.wikipedia.org/wiki/Guiberson_A-1020 The efficiency was 0.37 lb. per h.p. which is about equivalent to the toyota prius engine. Imagine what it could do with a bit of turbocharging and modern fuel injection. 

Given the differential between boats and planes, maybe these might become more popular. I think that they're classed as boats https://en.wikipedia.org/wiki/Ground-effect_vehicle

It would be nice to get a good idea of the diesel auto engine conversions out there. We might all be running on ethanol or biodiesel soon as the most cost effective solutions. The advantage of diesel is the efficiency and energy density of the fuels.

Both ethanol and biodiesel are pretty hard on plastic tanks though.

1 hour ago, Flying Binghi said:

If you were a ‘true believer’ then you would not fly and free up those carbon credits

I try to minimise my carbon emissions. However flight doesn't have a good alternative to carbon fuels. I'd love a plane which could fly on biodiesel which is a reasonably feasible projects. 

Did you know that there's a special page on wikipedia dedicated to climate change conspiracies. https://en.wikipedia.org/wiki/Global_warming_conspiracy_theory

However as I've stated I like to use profligate amounts of energy by travelling for pleasure, buying manufactured goods, swimming in winter and flying for fun. However as a someone with a vaguely scientific bent I don't see this as mutually exclusive to a zero carbon emissions philosophy. However to continue down this path I think that nuclear is the only real answer.

I believe that scientists are generally smarter and more believable than either football players, politicians and hairdressers. They put their theories up for public scrutiny and accept the criticism. They generally get promoted and remunerated for being right, not being popular or charismatic.

I also accept that at some point in the future we're going to be asked to demonstrate that we're carbon neutral and will get taxed when we're not.

On the other hand because you think that this science stuff is all junk you'll probably just get old and bitter. 

Bill Gates likes private jets and thinks that dumping CO2 is bad. So he offsets his carbon footprint.

https://www.ladbible.com/news/technology-bill-gates-spends-7000000-each-year-to-offset-his-carbon-footprint-20210215

So does Jeff Bezos.

https://www.cnbc.com/2021/11/05/why-bill-gates-and-jeff-bezos-buy-carbon-offsets-how-they-work.html

So it might be reasonable to enforce a carbon neutral policy on emission for all travel, but you can start with the rich.

On 04/09/2022 at 4:36 PM, Bruce Tuncks said:

I fly and believe in global warming. I would gladly remove the CO2 that I put in the air by my flying, but this would be futile unless everybody else did too.

Each liter of avgas used  would need approximately a kg of charcoal to be buried....  no real problem,

Here's another way of looking at the atmosphere...  1 cubic km of air weighs about 10^9kg and 1ppm is therefore 10^3kg or 1 tonne. So 1ppm = 1 tonne per cubic km.

If the atmosphere goes up to 15km ( ie could be replaced by a 15 km deep layer of 1kg/m^3 ) then there are 90 cubic km of air over this farm. ( yep, the farm is 1500 acres or 6 km^2 )

To lower the CO2 from 420ppm to 280ppm would mean removing 140 times 90 tonnes of CO2.

Wow , 12,600 tonnes of CO2 ! That is  possible but it will take years of work Gosh I hope somebody does a check and finds I have overstated the figures.

I find it easy to believe that 12,600 tonnes of CO2 could alter the thermal properties of this bit of atmosphere by enough for 2 degrees of warming.

I suspect that you're making it a bit hard for yourself, you don't need to work in volumes, just pressure will work. There's a column of air above every square meter of land the weight of that air creates a force of 101.3 kPa.

Divide this by gravity and you have about a ton of air above you. The % by weight of air that is CO2 is 0.063 and we want to reduce CO2 by about 0.25

This works out at about 16.2kg per m2 of CO2 or 4.4 kg m2.

So for above your farm of 1500/2.2 hectares 110454 tons of CO2 or 30123 tons of carbon.  There's a fair margin of error but you get the gist.

On 05/09/2022 at 9:23 AM, Flying Binghi said:

I would gladly remove the CO2 that I put in the air by my flying, but this would be futile unless everybody else did too

This is similar to the pissing in the pool argument. Yes I understand that people do it however most people don't, and while it isn't grand, it's better than the alternatives.

Also it's not the "global warming true believers" its what science says. You know that thing that allows engines to run, planes to fly and medicines to work. It really is that good.

Your views are in the same camp as the "world is flat", "that vaccines cause autism", "The UN and Bill Gates vaccines programs are sterilizing women" and "fluoridation is a communist plot". Take a look at https://en.wikipedia.org/wiki/List_of_conspiracy_theories#Science_and_technology

It has some corkers that you might want to believe in. I'm not out to hurt your feelings, but if you say dumb stuff I'll let you know, and I'm letting you know. 😉

1 hour ago, facthunter said:

You can still use the land for other things with wind and solar. My point was nuclear and fossil fuel add Heat to the system when they operate but solar lands here anyhow.  We are seeing in UKRAINE what risk we have with Nuclear and war.. Nev

I'm not really sure of your point here. Are you saying that burning either Coal or Uranium makes the world hotter as a heat  input.

Appreciate the allcaps but nuclear is the safest form of power generation, this includes deaths from Chernobyl and Fukushima  . https://www.altenergymag.com/article/2020/03/what-is-the-safest-energy-for-the-future/32904

I agree that what we're seeing in the Ukraine is cause for concern however the deaths are being cause by guns, bombs and bad people. About 14400 people have died so far in the war. None of them from nuclear power. This is a good example of perceived risk vs actual risk. It's a bit like the fear of flying.

53 minutes ago, Flying Binghi said:

Coal power is cheap and very reliable.

If you include greenhouse gas polution, coal is not cheap, none of the CO2 capture processes have come close to removing the carbon from the exhaust and they drive up the cost enormously.  China is going nuclear, solar and wind in a big way. 

"Coal's Dead" get over it and move on. It's not smart its dumb.

But we have gone a long way from the original topic of lead in fuel. Lead in fuel like coal and all the majority fossil  is a dead technology. Find good alternatives and move on. Don't try to persist the status quo as this just causes more harm.

17 minutes ago, facthunter said:

Nuclear and fossil fuel ADD heat to the aggregate. Using solar and wind does not. It's there from the sun anyhow so efficiency is not so important. WHITE hot salt stores power and you only need mirrors  to focus heat. Solar voltaics can make hydrogen from water when there's surplus power.. Nev

Fuel cost is a negligible input in nuclear. So efficiency isn't particularly important in that space either. However higher temperature plants can operate much more efficiently.

Solar salt has been more expensive than expected when implemented. You're better off installing solar PV panels and heating the salt electrically for storage.

Not to say that someone won't find a better way but no-one has become rich doing it yet.

In terms of land usage. https://www.nei.org/news/2015/land-needs-for-wind-solar-dwarf-nuclear-plants

Quote

 

A nuclear energy facility has a small area footprint, requiring about 1.3 square miles per 1,000 megawatts of installed capacity. This figure is based on the median land area of the 59 nuclear plant sites in the United States. In addition, nuclear energy facilities have an average capacity factor of 90 percent, much higher than intermittent sources like wind and solar.

By contrast, wind farm capacity factors range from 32 to 47 percent, depending on differences in wind resources in a given area and improvements in turbine technology. Solar PV capacity factors also vary based on location and technology, from 17 to 28 percent.

Taking these factors into account, a wind farm would need an installed capacity between 1,900 megawatts and 2,800 MW to generate the same amount of electricity in a year as a 1,000-MW nuclear energy facility. Such a facility would require between 260 square miles and 360 square miles of land.

A solar PV facility must have an installed capacity of 3,300 MW and 5,400 MW to match a 1,000-MW nuclear facility’s output, requiring between 45 and 75 square miles.

 

I was thinking something like this. It removes the residual humidity and lowers the risk of corrosion.

https://www.aviationconsumer.com/maintenance/engine-dehydrators-engine-saver-prevails/

38 minutes ago, kgwilson said:

The average Coal powered electricity generation plant is about 33% efficient.

Peak efficiency is just that and tends to fall off pretty quickly especially with turbines.  Solar cells are only about 20% efficient but the input is cheaper ;-).

One of my recent surprises was the combined heat and power systems are less efficient at electrical production than their standard brethren.  It's more cost effective and flexible to generate electricity more efficiently and buy heat pumps. Otherwise you need to force people to build close to power plants on tiny blocks.

Coal, oil and gas are fossil fuels bringing carbon back into the atmosphere from millions of years ago. It cheap (excluding pollution costs), energy dense and readily available often near to where the power is required.

Solar and wind are also cheap, however they are diffuse and intermittent. Wind as a resource is good for SA and Tasmania however not so much in other areas so you have

Another way of looking at the problem is to look at the following

https://en.wikipedia.org/wiki/Tûranor_PlanetSolar

Nice boat but with all those solar panels it generates 93kW under the best rated conditions. I used to have a subaru which could output 200kW all day and night. Even with the streamlined hulls it can only cruise at 5 knots. Michael Phelps swam at 3.8 knots setting the world record.

I love solar and wind and the new storage technologies. I just think that it's a bit of a fantasy thinking that they're going to sustain modern society in anything more than a bit part. I want zero carbon and I like to use lots of energy doing stuff like flying planes and travelling.

Unfortunately I think that this can only happen if something like nuclear takes the majority of the load. Fusion's still a generation away unless someone cracks something like muon catalyzed fuision

At the very least look what someone smart thinks about this subject. (They also point to the fact that old nuclear plants can only load follow slowly)

https://www.withouthotair.com/c26/page_186.shtml

He covers off on what is required for pumped storage to work in a country like the UK.

21 hours ago, facthunter said:

I've only mentioned that about FIVE times. Put the atomic weights in the equation to see that there's more water than hydrocarbon and don't run your engine for short periods and leave it sitting afterwards if you want a reliable engine.  Nev.

Is anyone using active extraction of water from the engine case? Ie an air pump going from the engine case to water absorbing beads to stop corrision?

One other thing, the way that markets work is that when things are plentiful they're cheap, when they're scarce they're expensive.

We want people to invest in solar, however they'll make little or no return once there's an excess of power so investment in plant stops.

The people storing power want to buy this power as cheaply as possible to store it however the solar farm operators need a return to recoup their investment costs. Do you install solar as a loss leader and vertically integrate or buy it on the market from the suckers who have already deployed the capacity.

Essentially in the market the daytime cost of power will tend towards zero as more plant is deployed. If you have a business that is energy intensive which can run in this window go for it, however if you need constant power you're out of luck.

This is the real cost of intermittency and its far larger than people think.

9 minutes ago, kgwilson said:

Baseload power is a misnomer in todays world. What is required is fast generation to deal with peak demand. Coal simply cannot do this as it needs to run at close to full capacity all the time to gain its maximum efficiency which is poor anyway. Nuclear is similar.

The term you want is dispatch-able power and nuclear can do this. The French have been running their reactors in a dispatchable manner for years and have demonstrated . Some newer reactors designs are inherently load following, by removing heat for power generation it increases the reaction rate.

12 minutes ago, kgwilson said:

A study done some 10 years ago by Sydney university identified more than 10,000 potential pumped hydro plants in Eastern Australia.

Actually have a look at that study and consider the impact of developing these sites. It would have a massive environmental impact. Most people don't remember the protests relate to damming some rivers in Tasmania however this proposes something with an impact 10 or 100 times the size.

Like planes everything's a compromise and all of these proposal come with huge environmental impacts. Wind farms and solar in German can't be rolled out because of the environmental impact of the high voltage power lines and local protests. Australia is seeing similar protests as landowners are being asked to accept infrastructure that the cities want but they get no gain from. They don't want to run the powerlines underground because it's too expensive. The people in cities don't want to pay for this excess. Politician will exploit this divide.

21 minutes ago, kgwilson said:

Batteries are getting cheaper with numerous new technologies

Yes they are however they're not free and they wear out, for example I just bought over a thousand Li Ion cells for a project from China. They're like car tyres in a few years they'll be shot and they'll need replacing. The tesla battery pack in SA is not economic in a daily cycling role however it makes money by:

• Getting paid for a power reserve function
• Delivering peak power when the prices is very high.

That way they maximize the return on the infrastructure without wearing the pack out.

I'm not saying that these technologies won't play a part however the scale of the problem is against them shouldering the bulk of the load. To do so would come at a considerable expense and consumers are used to things becoming cheaper not more expensive.

Rooftop solar is good, however it generates power when after you've driven to work (in your electric car) so you either need to store it for charging in the evening, or transfer it across the grid to the powered car park.

23 minutes ago, onetrack said:

Pumped hydro is the way forward for Australia, we have staggering amounts of sunshine, and the country is full of massive mining excavations that lend themselves nicely to pumped hydro.

Considering how dry and flat Australia I'm don't think that pumped hydro is a great idea. You need your holes in the right place and 99% of mines aren't.

Look at the real capacity of Snowy Hydro2 in terms of Annual output and look at its cost it really struggles to stack up.

To get your head around the scale of the problem have a look at https://www.withouthotair.com/ there's a downloadable book on the site. It is a simple read and gets away from stupid terms like "2000 households".

It was written by David Mackay and amongst other things was chief scientific advisor to the UK government. Bill Gates has also written a good book on the subject, simple enough for most people to get their heads around the subject.

Australia's electric energy consumption was 265TWh per annum.

47 minutes ago, facthunter said:

Concentrated heat direct from the sun and high temperature SALT. Synthesise the hydrocarbons. Most synthetic oil is made from gas. Nev

The problem with these systems is that they don't operate 24x7 they only operate efficiently between 10-2 so you have plant sitting idle for most of the day. Not great from a capital perspective. From a capacity factor point of view not very efficient even though the power source is free.

Whereas with a permanent industrial heat source it can operates 24x7. It all depends on the cost of the plant v the inputs.

You also need a carbon source as a feed.

There are a number of things which aren't mentioned in this article.

1. Renew Economy is anti-nuclear so any article like this should be taken with a grain of salt.
2. France is an energy exporter, it generally exports power to Germany and the UK and the rest of Europe. Normally it exports power at a profit. The argument is a bit like reserving Gas for domestic consumption in Australia. However we decided to sell our gas at prices lower than we can buy it.
3. Water based nuclear power plants operate at lower thermal efficiencies than either Gas or Coal. This is simply the law of thermodynamics. Times of drought impact these types of nuclear reactors more due to available water an differential temperatures. Newer generation high temperature reactors don't suffer in this way and can be designed to be water free.
4. France has some of the lowest Greenhouse emissions in Europe and Germany is the biggest emitter. 
5. France has demonstrated the ability to manage their nuclear fleet in a load following manner working hand in glove with renewables.

The French stance on nuclear appears to have been a winner for them. Germany has undergone an abrupt turnaround in their public sentiment towards nuclear recently 

This is not to say that their aging nuclear fleet doesn't have problems, they need to standardize on a new design and roll them out in a manner similar to their first plant rollout where they achieve significant economies of scale and lowered production costs. But they are better positioned than Australia and their emissions reflect this.

If we go down the path of electric vehicles we're going to need an enormous increase in capacity of the electrical system. Intermittent renewables are a great supplement but aren't suitable for industrial capacity or sporadic consumer demand. For instance the whole article relates to how painful the lack of availability can be, solar and wind are this to the core so going down that path will be painful. Hydro storage works well when it's wet however Europe is dry at the moment. Australia is always dry so hydro isn't an option.

Australia is missing a huge opportunity to develop new nuclear plants and it's a pity because none of the other technologies quite stack up. Hydrogen's a bit of a joke, Ammonia was dangerous in the 1930, biofuels are good but don't have the capacity, batteries are expensive and wear out and fossil fuels don't work without emitting CO2.

Fossil fuels are going to become a much smaller part of the economy going forward and maintaining a fuel with a known neurotoxin in this mix just isn't going to fly. So fasten you seatbelts and choose one which you think will last through the change. My bet is jetfuel because it's going to be difficult to find any alternatives any politicians love their travel, however an automotive fuel would also be a good bet. 

8 minutes ago, Old Koreelah said:

On climb, there are three ways to keep CHTs under control: open cowl flaps, ease off power...or go full throttle!

Just thinking, given the cooling and anti-knock effect. Its sounds like a lean efficient climb be achievable? Using fuel for cooling has always seemed a bit extravagant.

Also have you looked at the internals of the engine through a borescope, the water is meant to keep everything very clean.

Good to see it's being done.

How are you finding head/exhaust temperatures, engine sound etc?

Does anyone have a figure on how many planes received a dunking in the floods? Are they written off or are they likely to appear on the market at some point?

Injection into the inlet plenum works. There are some pretty simple systems out there that just use windscreen wiper pumps and a light to let you know that water levels are low.

You could also go for the STC version which is about $15000 or an off the shelf automotive system.

I've been playing with an arduino to provide better gear up landing warnings. However it occurred to me that a very similar system could automate the whole shebang as well however YMMV. Simple rules like > 80% power turn on injection are reasonable.

Water's pretty cheap octane improver. This paper suggests the following formula where w = water and f=fuel flow.

So if you wanted to standard 91 octane rated fuel in an engine which expects 98 you could inject a water to fuel ratio of .42 and have the added bonus of the heads running significantly cooler.  There's also the benefit of the cost savings. 91 is about $1.57, 98 is about $1.73 and avgas is current about $3.08 in Canberra at the moment. 

The main reason to include methanol/ethanol in the mix is as an antifreeze so if you're flying in conditions where icing is a concern it's a good idea.

The key point to remember is that you only need to do this at low altitudes and higher throttle settings, so the water tank can be reasonably small depending upon your flying.

In an ideal world it would be good if there was a combination of engine management system and a higher pressure pump connected to an injector to keep the water fuel ration in the right zone. Some car fuel injectors are stainless and can work for this purpose.

The main risk is additional water making it's way into the sump. But normal combustion products include water and it should only really be used in takeoff and climb. Cruise and landing temperatures should clear any excess moisture.

But in comparison to the damage and costs that high temperatures and detonation create it's a very manageable risk.

It is best to look at the Modulus of elasticity  and the Ultimate Tensile Strength (UTS) or Modulus of Rupture (MoR). You may not get the desired outcome if one material loads to failure before the other approaches 20%. (Also below I know the ratios are a thousand or so out but you get the gist)

MoE of Ironbark is 23GP, MoR 185 ( Ratio ~8)

MoE of Hoop Pine is 13GP, MoR 90  (Ratio ~6.9)

MoE of Balsa is 3.7, MoR 19.6 (Ratio ~5.2)

From

http://www.performance-composites.com/carbonfibre/mechanicalproperties_2.asp

MoE Std CF 70 GPa and UTS 600 (Ratio ~8.6)

MoE Eglass 30 GPa and UTS 440 (Ratio ~14.7)

This might imply that a match up of Carbon fibre and Ironbark or Hoop pine would, from a structural point of view be better than E-Glass in a propeller.

However you could also argue from a protective point of view the E-Glass would allow a safer failure mode by being having the ability to absorb failures of the internal material to an extent allowing a visible inspection to easily identify failures. It would also be under less load when surface damage occurs managing the associated stresses around the point of damage.

Bamboo is different again from wood, plus its a composite. I'd contact the manufacturer but you might scare them if you mention propeller.

This paper might give you insight into the challenges.  https://www.sciencedirect.com/science/article/pii/S1359836822001603

All woods (including bamboo even though its a hardened grass) use fundamentally the same building blocks and strength is somewhat proportional to density. However some timbers of similar density differ in strength as they use the underlying building blocks more or less efficiently.

I'll leave you with the pictures to mull over from one of the earlier articles I posted. All the adhesives bar one produce wet wood failure. They also noted that they had issues with the RF application leading to lower strength of some test samples. This demonstrates Markdun's right relating to the fact RF can be more difficult to apply compared to epoxy and that it can introduce technical risk.

A later test using acelylated timber shows the difference in treated timbers.

I have searched for any studies demonstrating newer epoxy formulations resistant to the standard de-lamination tests however I've only seen published successes when surface preparation treatments are used.

The manufacturers of the new improved epoxies might be able to point to successes in this area.

All, good robust debate and getting the facts on the table is always interesting. The key points which I was trying to make are as follows.

• Fixed pitch propeller design can be optimised to your cruise speed using freely available software. This should enable anyone with access to a large format CNC to develop wooden propellers optimised for their aircraft. Of course it is possible to do this by hand but your mileage may vary.
• When choosing timber for the props, there are a wide variety of timbers easily available in Australia which weren't available to manufacturers in Europe and the US.
• The thickness of the propeller can be reduced by leveraging stronger materials, increasing efficiency. However there may be a weight penalty. Similarly carbon fibre composite density is even greater. Also note that the bending moment increases as thickness decreases. Some Australian species have some interesting properties which while historically haven't been used in propeller construction might facilitate some design efficiencies.
• Generally resorcinol will produce a better, environmentally more resistant bond than epoxy. However joint quality, clamping pressure and minimum temperature are very important. It is far easier to produce a good bond with epoxy, hence why resorcinol has fallen from favour.

As an aside I grew up (a long time ago) helping to build and occasionally sail moths out of Australian Red cedar. While soft and light it didn't rot and bonded well. Supply was always interesting though.