Abstract: Combustion oscillation control in combustion systems using hydrocarbon fuels is provided by acoustically tuning a fuel-delivery line to a desired phase of the combustion oscillations for providing a pulse of a fuel-rich region at the oscillating flame front at each time when the oscillation produced pressure in the combustion chamber is in a low pressure phase. The additional heat release produced by burning such fuel-rich regions during low combustion chamber pressure effectively attenuates the combustion oscillations to a selected value.

Abstract: High dynamic pressure oscillations in hydrocarbon-fueled combustors typically occur when the transport time of the fuel to the flame front is at some fraction of the acoustic period. These oscillations are reduced to acceptably lower levels by restructuring or repositioning the flame front in the combustor to increase the transport time. A pilot flame front located upstream of the oscillating flame and pulsed at a selected frequency and duration effectively restructures and repositions the oscillating flame in the combustor to alter the oscillation-causing transport time.

Abstract: A compact document holder (20) which is maintained in a vertical position via tie-bars (24) and mounting brackets (26). The base of the holder is provided with an elongated ledge (36) extending outward to engage the document so as to maintain it secure within the holder. The tie-bars (24) facilitate the opening of the holder for the insertion of the documents as well as maintaining the document secure within the holder via the downward force provided by the weight of the document.