Accession Number : ADA514306


Title :   Initiation Mechanisms of Low-loss Swept-ramp Obstacles for Deflagration to Detonation Transition in Pulse Detonation Combustors


Descriptive Note : Master's thesis


Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA


Personal Author(s) : Myers, IV, Charles B


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a514306.pdf


Report Date : Dec 2009


Pagination or Media Count : 112


Abstract : In order to enhance the performance of pulse detonation combustors (PDCs), an efficient deflagration-to-detonation transition (DDT) process is critical to maintain the thermodynamic benefits of detonation-based combustion systems and enable their use as future propulsion or power generation systems. The DDT process results in the generation of detonation and can occur independently, but the required length is excessive in many applications and also limits the frequency of repeatability. Historically, obstacles have been used to reduce the required distance for DDT, but often result in a significant total pressure loss that lessens the delivered efficiency advantages of PDCs. This thesis evaluated various swept-ramp obstacle configurations to accelerate DDT in a single event PDC. Computer simulations were used to investigate the three-dimensional disturbances caused by various swept-ramp configurations. Experimental tests were conducted using various configurations that measured combustion shockwave speed and flame front interactions with the swept-ramp obstacles. Detonation was verified across the instrumented section through high-frequency pressure transducers, and experimental data proved that swept-ramp obstacles successfully accelerate the DDT process with minimal pressure losses.


Descriptors :   *PROPULSION SYSTEMS , *DETONATIONS , *IGNITION , *FLOW FIELDS , *THERMODYNAMICS , LOW LOSS , CONFIGURATIONS , PRESSURE , TRANSDUCERS , RAMPS , THREE DIMENSIONAL , INTERACTIONS , EXPERIMENTAL DATA , DEFLAGRATION , COMPUTERIZED SIMULATION , HIGH FREQUENCY


Subject Categories : Fluid Mechanics
      Thermodynamics
      Combustion and Ignition


Distribution Statement : APPROVED FOR PUBLIC RELEASE