Heat Shielding for a LP&HP duct system

[jrhagen]

I was just given a task to come up with a conceptual design for a heat shield for a LP/HP air bleed system. I am totally new to heat shield design. Can anyone direct me to a couple of good references so I can see what has been done in the past? I was looking at using some type of thermal blanket or small structural shields mounted to the engine. IMO I would like to see what worked in the past so I do not have to reinvent the wheel. TY in advance for any insight.

 

[tbuelna]

An adequate air gap is usually the lightest and cheapest form of thermal isolator. It will also help if you can make the pipes out of a low thermal conductivity material like Ti (at least for the HP bleeds).

Although I can't remember the name of the company that produced it, I do recall seeing a double wall design for tubing. It was for two-way flow in a fuel system (feed and return), but I imagine the same manufacturing process could be employed for a double wall, thermally isolated bleed air system.

As for design advice, take care to make sure the piping is properly strain isolated, and make sure that you allow for thermal growth mismatch between the structure and piping.

Good luck.