Heat fluxes to combustor walls during continuous spin detonation of fuel-air mixtures

Abstract

Pioneering measurements of heat fluxes to the walls of flow-type combustors of different geometries were performed in regimes of continuous spin detonation of fuel-air mixtures under unsteady heating. These heat fluxes are compared with those observed in the regime of conventional turbulent combustion in the same combustor. Air is used as an oxidizer, and acetylene or hydrogen is used as a fuel. For identical flow rates of the fuel, the heat fluxes to the combustor walls in regimes of continuous spin detonation and conventional combustion are close to each other; their mean steady values are ≈1 MW/m 2 (≈0.5% of the enthalpy flux of the products over the channel cross section). In both detonation and combustion regimes, the maximum heat fluxes penetrate into the walls in the mixing region (where the heat release occurs). In the case of detonation, regenerative cooling of the combustor walls by the flow of the fresh mixture occurs in the heat-release region (region of propagation of the detonationwave front). The regeneration becomes less effective in the downstream direction because of the shorter time of contact between the walls and the cold mixture and a longer time of contact between the walls and the hot products. More intense heating persists downstream of the front, where the regeneration ceases, but the temperature of the products is high. The character of heating of the wall in the region of rotation of the front of spin detonation waves depends on the number of these waves: the zone of the maximum heat release becomes narrower with increasing number of waves. Key words: continuous spin detonation of the fuel, flow-type combustor, fuel-air mixtures, heat fluxes to the walls.

Development of a Three-dimensional Transient Wall Heat Transfer Model of a Rotating Detonation Combustor

“…In order to implement this, the average angular wave speed must be known, determined by Eq. [3], where ∆t is the time taken to complete 1 revolution by the detonation wavefront.…”

“…Bykovskii et al 3 reported the first known heat flux measurements in an operational RDE and concluded that although the average heat fluxes to the combustor walls are similar in case of detonation and a conventional gas turbine combustor using deflagration, the peak heat flux can be 2-3 times higher. They identified the critical region experiencing highest temperatures is within the detonation region between the leading shock front and detonation front.…”

Propulsive Performance and Heating Environment of Rotating Detonation Engine with Various Nozzles

“…Quasi-steady heat transfer measurements are also important to determine the materials and thickness of chamber walls as well as cooling methods. Bykovskii and Vedernikov [26] revealed that the location of maximum temperature corresponded to the height of detonation waves. Braun et al [27] numerically quantified the convective heat flux in RDE using a reduced-order model and identified the highest time-averaged heat fluxes at the location of the triple point.…”

“…Even though an RDE could be operated without a throat, highheat-load problems were not inevitable. High-frequency analysis of heat flux [24] and steady-state analysis [25,26,28,29] of RDE have been conducted. Theuerkauf et al [24] developed a high-frequency response heat-flux gauge and revealed periodic heat flux in RDE caused by the rotating detonation wave.…”