A method for fabrication of a locomotive diesel engine turbocharger
turbine stage so as to avoid harmonic vibration in the turbine blades
when the engine is operated at pre-selected throttle settings. Upon
determining throttle settings for the engine and modeling of the
turbocharger therefor, at least one natural vibration frequency of the
turbine blades and a turbine nozzle vane excitation frequency as a
function of turbocharger rotation speed are determined. Then the data
obtained is analyzed to ascertain whether at least one data coincidence,
that is whether a rotation speed correlative of a throttle setting has a
coincidence over a predetermined range of both a natural frequency and
said turbine vane nozzle excitation. If not, the model is suitable for
fabrication of the turbocharger; if so, the model is modified by changing
blade stiffness and/or vane numbering until no data coincidences are
present.