The existing 3-stage turbine research facility at the Turbomachinery Performance and Flow
Research Laboratory (TPFL), Texas A and M University, is re-designed and newly installed to enable coolant
gas injection on the first stage rotor platform to study the effects of rotation on film cooling and heat
transfer. Pressure and temperature sensitive paint techniques are used to measure film cooling
effectiveness and heat transfer on the rotor platform respectively. Experiments are conducted at three
turbine rotational speeds namely, 2400rpm, 2550rpm and 3000rpm. Interstage aerodynamic measurements
with miniature five hole probes are also acquired at these speeds. The aerodynamic data characterizes the
flow along the first stage rotor exit, second stage stator exit and second stage rotor exit. For each rotor
speed, film cooling effectiveness is determined on the first stage rotor platform for upstream stator-rotor
gap ejection, downstream discrete hole ejection and a combination of upstream gap and downstream hole
ejection. Upstream coolant ejection experiments are conducted for coolant to mainstream mass flow ratios
of MFR=0.5%, 1.0%, 1.5% and 2.0% and downstream discrete hole injection tests corresponding to
average hole blowing ratios of M = 0.5, 0.75, 1.0, 1.25, 1.5, 1.75 and 2.0 for each turbine speed. To
provide a complete picture of hub cooling under rotating conditions, experiments with simultaneous
injection of coolant gas through upstream and downstream injection are conducted for an of MFR=1% and
Mholes=0.75, 1.0 and 1.25 for the three turbine speeds. Heat transfer coefficients are determined on the
rotor platform for similar upstream and downstream coolant injection. Rotation is found to significantly
affect the distribution of coolant on the platform. The measured effectiveness magnitudes are lower than that obtained with numerical simulations. Coolant streams from both upstream and downstream injection
orient themselves towards the blade suction side. Passage vortex cuts-off the coolant film for the lower
MFR for upstream injection. As the MFR increases, the passage vortex effects are diminished.
Effectiveness was maximum when Mholes was closer to one as the coolant ejection velocity is
approximately equal to the mainstream relative velocity for this blowing ratio. Heat transfer coefficient
and film cooling effectiveness increase with increasing rotational speed for upstream rotor stator gap
injection while for downstream hole injection the maximum effectiveness and heat transfer coefficients
occur at the reference speed of 2550rpm.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-05-273 |
| Date | 2009 May 1900 |
| Creators | Suryanarayanan, Arun |
| Contributors | Schobeiri, Taher M. |
| Source Sets | Texas A and M University |
| Language | English |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | application/pdf |
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