Fluid mixing apparatus using high- and low-pressure fluid streams

A fluid mixing apparatus comprising:

• a first annular wall defining a first passage in fluid communication with a source of a first fluid at a first pressure, the first annular wall including a bell-mouth shaped inlet facilitating flow into the first passage and directing fluid to an outlet;
• a second wall defining a first plenum in fluid communication with a source of a second fluid at a second pressure, the second wall disposed upstream of the bell-mouth shaped inlet, wherein the first pressure is less than the second pressure;
• a third wall defining a second plenum in fluid communication with a source of a third fluid, the second wall encompassing the third wall, wherein the third wall is at least partially surrounded by the second wall, and wherein the source of the third fluid is separate from the source of the first fluid and the source of the second fluid;
• a mixing conduit extending through the second plenum and fluidly connecting the first plenum and the first passage, the mixing conduit defined in part by the third wall, the mixing conduit defining at least one injection hole in fluid communication with the second plenum;
• wherein a flow of the second fluid through the mixing conduit entrains a flow of the third fluid flowing from the second plenum, through the at least one injection hole, into a passage defined by the mixing conduit, to produce a premixture of the second fluid and the third fluid;
• wherein the mixing conduit conveys the premixture into the first passage;
• and wherein, within the first passage, the premixture draws a flow of the first fluid into and through the first passage to produce a mixture of the first fluid, the second fluid, and the third fluid,
• wherein the first fluid and the second fluid are low pressure air and high pressure air, respectively, and wherein the third fluid is a fuel, and
• wherein the fluid mixing apparatus is installed along a combustor liner of a gas turbine combustor, such that the mixture of the first fluid, the second fluid, and the third fluid is directed in a substantially radial direction into the combustor liner.