Suppression of nonlinear oscillations in combustors with partial length acoustic liners

An analytical model is formulated for a three-dimensional nonlinear stability problem in a rocket motor combustion chamber. The chamber is modeled as a right circular cylinder with a short (multi-orifice) nozzle, and an acoustic linear covering an arbitrary portion of the cylindrical periphery. The combustion is concentrated at the injector and the gas flow field is characterized by a mean Mach number. The unsteady combustion processes are formulated using the Crocco time lag model. The resulting equations are solved using a Green's function method combined with numerical evaluation techniques. The influence of acoustic liners on the nonlinear waveforms is predicted. Nonlinear stability limits and regions where triggering is possible are also predicted for both lined and unlined combustors in terms of the combustion parameters

"Thumb carpometacarpal joint volar dislocation: A case report "

Dislocation of the thumb carpometacarpal joint is a rare injury, and only 38 cases have been definitively described in the English-speaking literature. All the reported dislocations have been dorsal. We present a volar form of the thumb carpometacarpal dislocation which was managed surgically after three months from the injury with open reduction and volar ligament reconstrction, with satisfactory outcome