Effects of Inlet Flow Conditions on the Performance of Equiangular Annular Diffusers

Effects of casing angle on the performance of parallel hub axial annular diffuser

“…The graph shows that swirl does not affect the magnitude of intensity and nature of the distribution. The nature of turbulence intensity for swirl and non-swirl flow at the inlet is similar to the studies by Coladipietro et al [10] and Hoadley [22].…”

“…The pressure recovery rises with a swirl flow as compared to non-swirl flow at the The C P varies with AR and Cp for the dimensionless length for the non-swirling flow as shown in Figure 17(i, ii) respectively. The obtained simulation result shows the meticulous agreement with the outcomes of Sovran and Klomp [6]; Coladipietro et al [10] for the three tested diffusers (A, B, C). The diffuser B produces the highestpressure recovery in comparison to the other two type diffusers, as reflected by the curves in Figure 17(i, ii).…”

“…Measurements of the pressure recovery, loss of total pressure, velocity profile in terms of boundary layer growth, and turbulence level were taken. Coladipietro et al [10] reported that in the short diffusers, the variation of pressure recovery with blockage was similar to the channel and conical diffusers. The findings show that pressure recovery decreases with increasing blockage.…”

Flow Development Through Inter-Turbine Diffusers

“…The static pressure rise through the diffuser is strongly dependent upon both the inlet swirl angle and the cant angle. Coladipietro et al (1975) and Kumar et al (1980) both reported that for unstalled, straight-walled annular diffusers the static pressure rise coefficient increased with increasing swirl. Kumar et al (1980) also reported that as the inlet swirl angle was increased the pressure rise reached a peak and then decayed with further swirl increase.…”

Experimental Validation of Numerically Optimized Short Annular Diffusers

“…Axial cascades more closely simulated tur bomachinery flow conditions but were often simple fixed flat vanes of poor design-it was difficult to isolate the influence of swirl from cascades that also developed different turbulence intensity, velocity, or total pressure gradients; vorticity or wake shedding; and inlet aero dynamic blockage [5], Most studies that evaluated swirl in diffusers [8,[19][20][21][22][23] reported acceptable amounts of pressure recovery for swirl angle below 30 deg, and a rapid loss thereafter. Axial cascades more closely simulated tur bomachinery flow conditions but were often simple fixed flat vanes of poor design-it was difficult to isolate the influence of swirl from cascades that also developed different turbulence intensity, velocity, or total pressure gradients; vorticity or wake shedding; and inlet aero dynamic blockage [5], Most studies that evaluated swirl in diffusers [8,[19][20][21][22][23] reported acceptable amounts of pressure recovery for swirl angle below 30 deg, and a rapid loss thereafter.…”