snoopyWWIace
22nd Jun 2021, 17:44
Question about P&W PT6 fuel pressure, but first a little context. I'm trying to simulate some PT6 engine data for a virtual reality project. I'm confused by the fuel pressure in different parts of the fuel system when the engine is starting up.
As I understand it (and correct me if I'm wrong) the FCU has a minimum pressurizing and shutdown valve that ensures the fuel pressure exiting the FCU is at least 100 psi (or maybe psia). HOWEVER, the primary manifold clearly fires before the secondary manifold. This is puzzling because the flow divider allows fuel to the secondary manifold if fuel pressure is greater than 17 psi. Well, the fuel pressure coming out of the FCU should be grater than 100 psi, so why doesn't the secondary manifold fire up immediately instead of after the first manifold?
As I understand it (and correct me if I'm wrong) the FCU has a minimum pressurizing and shutdown valve that ensures the fuel pressure exiting the FCU is at least 100 psi (or maybe psia). HOWEVER, the primary manifold clearly fires before the secondary manifold. This is puzzling because the flow divider allows fuel to the secondary manifold if fuel pressure is greater than 17 psi. Well, the fuel pressure coming out of the FCU should be grater than 100 psi, so why doesn't the secondary manifold fire up immediately instead of after the first manifold?