ANALYTICAL AND EXPERIMENTAL ANALYSIS OF REACTANTS VELOCITY EFFECT ON INSTABILITY OF PREMIXED COMBUSTION CHAMBER

摘要

Nowadays, combustion chambers of gas turbines, in order to be utilized in low NO_x emission applications, take advantage of lean premixed combustion, extensively. However, this category of gas turbines is susceptible to combustion instability. This paper aims at investigating of reactants velocity effect on oscillations generated during combustion instability of premixed combustion chambers. In this regard, experimental and analytical approaches are employed and good agreement is observed between both methods. In experimental phase, histogram of density functions and the state space distributions of the pressure oscillations are derived to distinguish the combustion instability for divers operating conditions. In analytical phase, reactants velocity effect on combustion instability if studied. According to the results, it is observed that by increasing the reactants velocity, instability frequency and oscillations amplitude are intensified. Moreover it is confirmed that the variation of instability frequency and oscillations amplitude with respect to the reactants velocity is linear.