LostCosmonaut

Aerospace Pictures and Art Thread

2,048 posts in this topic

36b.jpg

 

24590638583_351333e12e_b.jpg

 

Indian Air Force 707s, modified with some sort of cheek arrays.  Synthetic aperture radar seems likely, but it could be something else.

Share this post


Link to post
Share on other sites

DdjlPQi.jpg

 

These are valve-timing gears from the Bristol Hercules radial engine.  This engine powered a number of mid-WWII British aircraft including the Beaufighter and Stirling.

 

The Hercules used sleeve valves, which reciprocate independently of the pistons and thus require this giant mess of drive gears.  In the late 1930s there were a number of fairly convincing papers that predicted that aircraft engines would plateau in power density unless they switched to sleeve valves.  In actuality, conventional poppet valves were greatly improved and by the time aircraft sleeve valve engines were mature they had only modest power advantages over poppet-valve designs.

Zyklon, LoooSeR, Sturgeon and 1 other like this

Share this post


Link to post
Share on other sites
1 hour ago, Collimatrix said:

DdjlPQi.jpg

 

These are valve-timing gears from the Bristol Hercules radial engine.  This engine powered a number of mid-WWII British aircraft including the Beaufighter and Stirling.

 

The Hercules used sleeve valves, which reciprocate independently of the pistons and thus require this giant mess of drive gears.  In the late 1930s there were a number of fairly convincing papers that predicted that aircraft engines would plateau in power density unless they switched to sleeve valves.  In actuality, conventional poppet valves were greatly improved and by the time aircraft sleeve valve engines were mature they had only modest power advantages over poppet-valve designs.

 

 

That's crazy complicated, the R-2800 master race!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now