Da’ Fuser TeamTurbojet Diffuser Study

Progress Report 1

Robby SwoishRobby SwoishMike VostrizanskyMike VostrizanskyRyan WiltshireRyan WiltshireOctober 27, 2005October 27, 2005

ObjectivesObjectives

• Reduce length by increasing diffusion Reduce length by increasing diffusion angle without inducing separationangle without inducing separation

• Maximize pressure gain, thereby Maximize pressure gain, thereby increasing burn efficiency.increasing burn efficiency.

• Maintain uniform flow into combustor Maintain uniform flow into combustor allowing for uniform mixing allowing for uniform mixing distributiondistribution

OutlineOutline

Must create nozzles to provide for Must create nozzles to provide for flows of Mach 0.3, 0.35, and 0.4flows of Mach 0.3, 0.35, and 0.4

Test original model for separation Test original model for separation and efficiency to use as a and efficiency to use as a benchmarkbenchmark

Modify modelModify model Test modified model for separation Test modified model for separation

and efficiencyand efficiency

OverviewOverview

Pressure Taps

Divergence Angle

Combustor Entrances

Yarn for Flow Visualization

Entrance fromCompressor

• Two Identical models

• One Tests Visual Effects, i.e. location of Separation

• One Measures Pressure Data for Mach calculations

Matching Conditions/ Matching Conditions/ Theoretical Area Ratio’s Theoretical Area Ratio’s for quasi 1D flowfor quasi 1D flow Computed necessary choke hole area with Computed necessary choke hole area with

area-Mach relation:area-Mach relation: A

A MM

*

2

22

1

11 2

11

1

2

Desired Mach NumberDesired Mach Number Throat Area (mmThroat Area (mm22)) Throat Radius (mm)Throat Radius (mm)

0.300.30 1096.271096.27 18.6818.68

0.350.35 1254.721254.72 19.9819.98

0.400.40 1403.081403.08 21.1321.13

Experimental SetupExperimental Setup

TEST 1:TEST 1: 10/21/200510/21/2005

Goal: Characterize incoming flow Goal: Characterize incoming flow Mach numberMach number

Expected Results: 19.05 mm Expected Results: 19.05 mm radius used; Mach 0.30 expectedradius used; Mach 0.30 expected

Results: Mach 0.07 calculated Results: Mach 0.07 calculated from pressure measurementsfrom pressure measurements

TEST 1: TEST 1: 10/21/200510/21/2005

Possible Sources of Error:Possible Sources of Error:– Pressure LeaksPressure Leaks– Pitot Probe ErrorsPitot Probe Errors

MisalignmentMisalignment Plugged ProbePlugged Probe

– Inlet DisturbancesInlet Disturbances Follow Up Tests:Follow Up Tests:

– Increase choke area until desired Mach Increase choke area until desired Mach number is reachednumber is reached

Investigation Schedule Progress (weeks)Investigation Schedule Progress (weeks)

Potential ModificationsPotential Modifications

Boundary Layer Control By:Boundary Layer Control By:– SuctionSuction– BlowingBlowing– VanesVanes– Flow Control RailsFlow Control Rails– High Inlet TurbulenceHigh Inlet Turbulence– Other Vortex GeneratorsOther Vortex Generators