rrrr
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I know we have a bunch of pilots here, and also warbird enthusiasts, so I wanted to share a website I found. It has some amazing information and photos concerning the rugged and deadly Republic Aviation P-47 Thunderbolt, the "Jug". This airplane filled in the need for a long range escort fighter for American bomber forces between late 1943 and mid 1944, before the P-51 Mustang appeared and became the dominant fighter of the European theater.
Even so, the "Jug" was known as a powerful dogfighter and terror inducing tactical ground attack weapon. German troops were known to fear the aircraft, which they called the "Jabo", derived from the German Jäger-Bomber or Fighter-Bomber. The D model was fitted with 10 underwing 5" rockets, which could easily destroy freight trains and Wehrmacht armored columns.
If you look at a photo of a Thunderbolt, the first glance shows it has a huge fuselage. Compare it to the size of the cockpit canopy. I knew the reason for that was because the turbocharger was placed behind the pilot, but I had no idea just what was involved with how it was plumbed and making the system work.
What's going on here?
The answer is related to the 2,400 HP 18 cylinder Pratt & Whitney R-2800 Double Wasp engine that powered the Thunderbolt. The R-2800 in the P-47 was turbocharged, and the manner in which this was accomplished and the size of the components is astounding.
First of all, at an altitude of 25,000', the sea level atmospheric pressure of 14.7 PSI is around 5 PSI. This had huge implications for the amount of air the engine required to produce its rated horsepower, and just as importantly, the amount of air needed to cool the intake charge after it left the turbocharger.
Every part of the induction system and exhaust plumbing, the intercooler, the ducts, and the turbocharger were huge. Massive. Seeing the entire setup on a static display stand reveals just how much engineering was required to make it all work.
The National Museum of WW II Aviation in Colorado Springs, CO, has one of these static displays, and it's amazing to look at.
I'll post a couple of photos, but you need to visit the website to get the full story. I was blown away by how big all of the parts are. Take a look at the turbocharger and the intercooler. Realize you're seeing just one half of the intercooler, the other half is concealed by the port side cooling air overboard dump ductwork. The turbocharger, manufactured by GE, was the same one used on the B-17's Wright R-1820 radial, but seeing it in the context of a fighter instead of a four engine bomber reveals just how big it is.
Here's a front view of the the big P&W radial. Take a look at the size of the turbocharger and intercooler supply inlet and duct, which runs under the cockpit. The twin engine exhausts were outboard of the air inlet duct. The compressed charge air ducts feeding the engine were routed on either side of the pilot.
With regards to the advancement of aviation in general, and particularly the genius involved in engineering the Thunderbolt, consider the complexity of the aircraft as a whole. While the reason for the incredible pace of innovation in aviation since World War I was obviously a second World War, it's simply astounding to consider the capabilities of the aircraft compared to WWI designs that were the pinnacle of the industry less than thirty years before.
The fighter aircraft of that era were constructed with wood and linen fabric, flew at altitudes generally less than 5,000', speeds close to 100 MPH, and had one or two primitive machine guns as armament. The P-47 could dogfight at altitudes over 20,000', exceeded 400 MPH doing it, had eight wing mounted Browning 50 caliber machine guns, and could also carry rockets or thousands of pounds of bombs under the wings.
I hope you enjoyed exploring the inner workings of the "Jug" as much as I have.
The museum website:
https://lynceans.org/all-posts/the-complexity-of-a-ww-ii-p-47-thunderbolts-powerplant/
Even so, the "Jug" was known as a powerful dogfighter and terror inducing tactical ground attack weapon. German troops were known to fear the aircraft, which they called the "Jabo", derived from the German Jäger-Bomber or Fighter-Bomber. The D model was fitted with 10 underwing 5" rockets, which could easily destroy freight trains and Wehrmacht armored columns.
If you look at a photo of a Thunderbolt, the first glance shows it has a huge fuselage. Compare it to the size of the cockpit canopy. I knew the reason for that was because the turbocharger was placed behind the pilot, but I had no idea just what was involved with how it was plumbed and making the system work.
What's going on here?
The answer is related to the 2,400 HP 18 cylinder Pratt & Whitney R-2800 Double Wasp engine that powered the Thunderbolt. The R-2800 in the P-47 was turbocharged, and the manner in which this was accomplished and the size of the components is astounding.
First of all, at an altitude of 25,000', the sea level atmospheric pressure of 14.7 PSI is around 5 PSI. This had huge implications for the amount of air the engine required to produce its rated horsepower, and just as importantly, the amount of air needed to cool the intake charge after it left the turbocharger.
Every part of the induction system and exhaust plumbing, the intercooler, the ducts, and the turbocharger were huge. Massive. Seeing the entire setup on a static display stand reveals just how much engineering was required to make it all work.
The National Museum of WW II Aviation in Colorado Springs, CO, has one of these static displays, and it's amazing to look at.
I'll post a couple of photos, but you need to visit the website to get the full story. I was blown away by how big all of the parts are. Take a look at the turbocharger and the intercooler. Realize you're seeing just one half of the intercooler, the other half is concealed by the port side cooling air overboard dump ductwork. The turbocharger, manufactured by GE, was the same one used on the B-17's Wright R-1820 radial, but seeing it in the context of a fighter instead of a four engine bomber reveals just how big it is.
Here's a front view of the the big P&W radial. Take a look at the size of the turbocharger and intercooler supply inlet and duct, which runs under the cockpit. The twin engine exhausts were outboard of the air inlet duct. The compressed charge air ducts feeding the engine were routed on either side of the pilot.
With regards to the advancement of aviation in general, and particularly the genius involved in engineering the Thunderbolt, consider the complexity of the aircraft as a whole. While the reason for the incredible pace of innovation in aviation since World War I was obviously a second World War, it's simply astounding to consider the capabilities of the aircraft compared to WWI designs that were the pinnacle of the industry less than thirty years before.
The fighter aircraft of that era were constructed with wood and linen fabric, flew at altitudes generally less than 5,000', speeds close to 100 MPH, and had one or two primitive machine guns as armament. The P-47 could dogfight at altitudes over 20,000', exceeded 400 MPH doing it, had eight wing mounted Browning 50 caliber machine guns, and could also carry rockets or thousands of pounds of bombs under the wings.
I hope you enjoyed exploring the inner workings of the "Jug" as much as I have.
The museum website:
https://lynceans.org/all-posts/the-complexity-of-a-ww-ii-p-47-thunderbolts-powerplant/
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