The sole concern with A Squared's calculation is that it assumes thermal equilibrium is reached for the assumed gear strut mass (i.e., plenty of time for the thermal energy to diffuse through that mass) -- whereas in reality, we're talking about on the order of a half-second for strut compression. During this short time, the fluid friction would transfer heat to the comparatively tiny local mass of steel surfaces adjacent to the heat source. Bottom line, the uppermost piston and cylinder steel surfaces would see a drastically higher peak temperature rise than would the bulk mass of the strut.
As I said in my previous post (having run the same sort of back-of-the-envelope calc), I thought the temperature rise of the whole strut would be under 50 deg C, and I remain in agreement with A Squared on that front. And since pulse1 described the entire lower leg being blue, I still think there was probably some other cause at play in that large-scale thermal damage.
But I'm leaving the door just a little cracked in my mind that during a violently hard landing, some small, localized surface (e.g., upper piston) could possibly get hot enough to blue steel (over 275 deg C). I just can't quite rule it out intuitively without seeing actual data or a dynamic thermal analysis.
You generated an interesting sub-discussion, pulse1.
Last edited by Mach Stall; 4th Aug 2016 at 17:30.