An experimental investigation is carried out to characterize the flow through a shallow single serpentine curved convergent nozzle with an aft deck under fully expanded and underexpanded conditions with nozzle pressure ratios ranging from 1.1 to 2.2 for cold flows by wall static pressure measurements and flow visualization of the exit jet. The study revealed initial deceleration of the flow due to the turning of the streamlines caused by the nozzle curvature. Asymmetric coefficient of pressure variation in the cross-stream direction across various nozzle pressure ratios was observed, which is caused by secondary flow created by wall curvature and transition. The acceleration of the core flow due to geometric transition, as well as the additional nozzle length, causes early transition to sonic and supersonic flows, resulting in the formation of shock cells at relatively lower Mach number in the absence of the aft deck, as can be seen from the schlieren images. However, the presence of the constant area extension section reduced the flow asymmetry. Furthermore, the presence of the aft deck prevented the formation of barrel shocks and is expected to prevent the formation Mach disk(s) at higher nozzle pressure ratios. Thus, the curvature, transition, and aft deck complemented each other.
Flow Characterization for a Shallow Single Serpentine Nozzle with Aft Deck
Journal of propulsion and power ; 33 , 5
2017
Article (Journal)
English
Flow Characterization for a Shallow Single Serpentine Nozzle with Aft Deck
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