Why swept back wings are good

Why are plane wings angled backward? Today most planes have a swept wing design and this helps the plane fly faster, but it wasn’t always this way. Let’s look back in time and learn how this technology was developed and what we learned in the process. Back in 1941, most planes were designed with a […]

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SpaceX to Mars? How?

For as long as humans have walked on this earth, we have stared into the black expanse of space. Wondering where our place in the universe was and why we are here. The rhythm of the moon’s phases has guided humanity for millennia, but Galileo was the first to point a telescope towards it and […]

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The one error that Spitfire Designers made

There are few planes in history that are as admired as the Supermarine Spitfire, it played a pivotal role in the battle for air supremacy during World War 2. Its iconic thin elliptical wings minimised drag, making it incredibly agile. But, its German counterpart the Messerschmitt was a worthy adversary. Both planes could reach speeds of up to 560 km/h, powered by huge V-12 piston engines. They were remarkably similar planes, featuring low-slung wings, which increased their manoeuvrability. A rapid departure from the biplane era from which their pilots came. Both planes featured retractable landing gears, which many pilots were unfamiliar with causing some to forget to lower their wheels for landings.

But the early versions of the Spitfire had an alarming flaw, when performing negative
g manoeuvres the engine would cut-out.

To understand what is happening here we need to learn what a carburettor does and how it works. A carburettor is a device that blends air and fuel for an internal combustion engine. The carburettor used in the Merlin engine used a float to control the flow of fuel into the carburettor tank, similar to how a toilet cistern works. The level here is important as it effects the flow rate into the mixing chamber. A higher level will result in a higher pressure at the bottom of the fuel chamber. There is a low pressure zone created at the nozzle with the venturi effect, which is the reduction in fluid pressure as it passes through a constriction.

This pressure difference draws fuel from the float chamber, a larger pressure difference
will result in a richer fuel mixture. This air/fuel mixture continues on and enters the
piston cylinder to power the engine. The air/fuel mixture percentage can be altered by opening and closing two valves in the carburettor. One is called the choke valve which closes when starting the engine, this increases the drop in pressure even more and draws more fuel from the float chamber, resulting in a richer air fuel mixture, which is needed when starting the engine, but an over-rich fuel mixture will not cause an increase in power, it will actually stall the engine. Remember this for later. The second valve is the throttle valve, which is controlled by the accelerator. When the accelerator is fully depressed this valve will be open to allow the maximum amount of air and fuel to enter the engine.

Now this type of carburettor was okay for early cars, but for a plane that can turn
upside and enter deep dives, it struggles. If a plane fitted with this system enters
a negative g dive, fuel is forced to the top of the float chamber. This results in the loss
of power as fuel can no longer enter the engine, but the float is now forced
down, which opens this needle valve allowing fuel to enter the float chamber, if this manoeuvre is held too long too much fuel will enter the float chamber resulting in an over rich air fuel mixture will flood the engine and stall it, possibly making it impossible to start again.
German pilots quickly realised this flaw and it gave them an edge in dog fights as their
planes used a fuel injection system, which didn’t suffer from this problem.
With the war raging Britain needed a quick fix for this problem and this is where Beatrice Shilling came in. Beatrice was a young female engineer working for the Royal Aircraft Establishment. She came up with a beautifully simple stopgap solution for the problem. She installed a simple brass ring between the end of the fuel intake pipe and the entrance to the carburettor chamber. This restricted fuel flow into the carburettor to the maximum it needed during a dog fight. This did not solve the initial fuel starvation problem, but it did delay the more serious problem of flooding the engine. This allowed the spitfire pilots to be far more competitive until the new pressure carburettors were installed in 1942.

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How to make Planes fly faster

There is a really simple rule that influences the design of every jet plane you’ve ever flown on in profound ways, and once you know about it, you’ll start seeing its effect everywhere. It tells us why engines are placed slightly in front of wings, and why the fuselage of supersonic planes narrows along the […]

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What would happen if the US government cared about NASA?

The United States spends roughly $600 billion per year on the military, which is about 54% of its annual budget. By comparison, NASA only receives $18.5 billion per year, which is >0.5% of the annual budget. I won’t go into whether or not the US needs such a huge military, but here are some facts:

  • The next biggest spender is China, at $190 billion per year.
  • China has 500 of their Type-99 tanks, which are outclassed by the US M1 Abrams, of which the US has 8700.
  • The US has 10 aircraft carriers, the rest of the world combined has 10 smaller aircraft carriers.
  • There are 8400 attack helicopters around the world, of which the US owns 6400.
  • One single tomahawk missile costs around $1.5 million, alongside this you have salaries to pay, munitions to buy, fuel to use, etc. This all adds up to the $600 billion figure.

The general public’s interest in space exploration has gradually dwindled since the space race of the 60s, and now that there are no Russians to compete against, no one feels compelled enough to spend significant resources on new missions. But what would happen if the military’s budget and NASA’s budget got switched? For perspective, the entire cost of the Apollo programme was $136 billion 2007 dollars over 13 years, or just over $10 billion per year. In this article, I won’t get into admin or R&D that would have to get done to make these things possible.

First of all, NASA loves telescopes, probes, and satellites. With the massive budget, the 10-20 years it would take to launch all of their projects could be cut down into just 1-2 years. Infrastructure upgrades could be developed to allow faster transmission of data from new missions.  With all these resources in orbit, new discoveries would be made much more frequently, both on Earth and in the cosmos. This could rekindle the public interest in space.

The smartest decision NASA could make would be to fund some smaller privately owned space exploration groups, such as SpaceX. They could fund new space stations, reusable space planes, asteroid mining operations and lunar bases. Pushing further out into science fiction, once a lunar base is established, electromagnetic launchers could be used to put large spaceships into lunar orbit or on trajectories to Mars or beyond. That would be the fastest way to colonise Mars, have the moon as a halfway house to stage future missions.

The International Space Station (ISS) costs about $100 billion spread out over a decade, so think of the massive highly advanced space stations that could be put into orbit with 6 times that amount per year. That amount of money and a massive base of operations in orbit could support a core of thousands of active astronauts, with a few hundred of these on simultaneous manned missions. Serious planning could begin to send astronauts to the Jovian system, though it might take several decades to become feasible, even with the massive budget.

With a $600 billion budget, it would be feasible to colonise Mars in just under 10 years. If the entire budget was spent on transporting people and supplies to Mars in shared rockets, in 10 years we could see a population of 40,000 people. Then there are the intriguing celestial bodies currently out of reach to mankind. We could send robotic explorers to them all. For example we could send submarines to Europa, a moon that has been postulated to have extra-terrestrial life beneath its frozen surface in the icy waters.

While this is all hypothetical, if NASA got this huge budget, it is safe to assume the scientific community would be inundated with new data and off world colonies could easily become a reality in our lifetime, with the possibility of interstellar travel.

 

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The Future of Supersonic flight

NASA has achieved a significant milestone in its effort to make supersonic passenger jet travel over land a real possibility by completing the preliminary design review of its Quiet Supersonic Transport or QueSST aircraft design. QueSST is the initial design stage of NASA’s planned Low Boom Flight Demonstration experimental airplane, otherwise known as an X-plane.

Senior experts and engineers from across the agency and the Lockheed Martin Corporation concluded that the QueSST design is capable of fulfilling the aircraft’s mission objectives, which are to fly at supersonic speeds, but create a soft “thump” instead of the disruptive sonic boom associated with supersonic flight today. The X-plane will be flown over communities to collect data necessary for regulators to enable supersonic flight over land in the United States and elsewhere in the world.

NASA partnered with lead contractor, Lockheed Martin, in February 2016 for the QueSST preliminary design. Last month, a scale model of the QueSST design completed testing in the 8-by 6-foot supersonic wind tunnel at NASA’s Glenn Research Center in Cleveland.

“Managing a project like this is all about moving from one milestone to the next,” said David Richwine, manager for the preliminary design effort under NASA’s Commercial Supersonic Technology Project. “Our strong partnership with Lockheed Martin helped get us to this point. We’re now one step closer to building an actual X-plane.”

After the success of completing the preliminary design review, NASA’s project team can start the process of soliciting proposals later this year and awarding a contract early next year to build the piloted, single-engine X-plane. The acquisition for the X-plane contract will be fully open and competitive, with the QueSST preliminary design data being made available to qualified bidders. Flight testing of an X-plane could begin as early as 2021.

Over the next few months, NASA will work with Lockheed on finalizing the QueSST preliminary design effort. This includes a static inlet performance test and a low-speed wind tunnel test at NASA’s Langley Research Center in Hampton, Virginia.

Image result for nasa supersonic jet

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