Mosquito cooling system.

[Black-Witch]

Does anyone know about the cooling system on the Mosquito?

 

In particular, Merlin's fitted to Mosquito's all had "Reverse coolant flow direction", and were not interchangeable with other similar Merlin's with "normal" coolant flow direction.

 

why?

[Barnacles]

24 minutes ago, Black-Witch said:

Does anyone know about the cooling system on the Mosquito?

 

In particular, Merlin's fitted to Mosquito's all had "Reverse coolant flow direction", and were not interchangeable with other similar Merlin's with "normal" coolant flow direction.

 

why?

Maybe it's because there was a port and starboard engine for mosquitos which necessitated a different coolant flow because of the position of the radiators? 

 

That rings a bell. 

[Black-Witch]

1 hour ago, Barnacles said:

Maybe it's because there was a port and starboard engine for mosquitos which necessitated a different coolant flow because of the position of the radiators? 

 

That rings a bell. 

There weren’t L & R engines for the Mosquito. 

[Art-J]

Barnacles probably guessed 50% right - about radiator position rather than about existence of port and starboard unit.

 

"Normal" flow in all standard Merlin versions (with rads usually mounted directly or not far below engine) was: pump -> block -> header tank -> rad -> pump.

 

"Reversed" flow for dedicated Mossie versions (both in 20- or 60- series derivatives) was: pump -> rad -> block -> header -> pump. 

 

I'm only speculating here, but when you think about it, with rads located above engines in wings, the reversed system simply offers shorter plumbing all around compared to normal one, and that's what you're always aiming at when designing any flow system.

 

Did DH Hornet also feature wing mounted rads? I don't remember. And if so, which Merlin variants did it use...

[Black-Witch]

Thanks Art-J,

 

That all makes perfect sense except that the Merlins in the mosquito were not compatible with any other aircraft. If it was "just" the coolant pipework that was different then they could have used Merlin 24's instead of 25's. so there must also have been something different in the engine, or the coolant pump, that made Mosquito engines exclusive to Mosquito's.

 

As for the Hornet, it also used leading edge wing rad's and had a L & R engine.

Edited September 17, 2023 by Black-Witch