Has anyone come across some research regarding the thermal entrance length for a pipe that has many steps / changes in diameters? I suppose the same question follows for hydrodynamic entrance length
I am wondering how to calculate the Graetz number (Dh/L)*Pr*Re and wondering how "long" my pipe...
Thank you for that explanation, it is quite clear that the phase shift associated with passing the first critical speed in 1 direction (for asymmetric bearing stiffness) will cause synchronous reverse whirl leading up to the second critical speed (in the opposing direction).
I think the way i...
Thank you for the clarification.
I do understand that the forcing function (frequency) will drive the steady state response of the equations of motion.
However I am still stuck on spinning vs. whirling, as the external force in an unbalance analysis is - spinning forward -, not necessarily...
My initial interpretation was that any off axis deflection would result in synchronous whirl as the “whirl” would be “driven” by the spin of the shaft that was still on the axis (I.e. at a bearing). However it seems as though whirl and spin can be treated independently (since you can have both...
I’ve seen many anecdotes in papers that suggest that imbalance forces have a component in the forward direction, or unbalance forces can be considered “forward whirl forces” - but I can’t picture it on a FBD. The unbalance force points out radially (to me) and shouldn’t have a component forward...
