Session: 33-02 Experiments of particle deposition in engine components

Paper Number: 129054

129054 - The Effect of Thermal Cycling on Deposition in an Impingement/Effusion Cooling Geometry 

Experiments were conducted in a high-pressure deposition facility to study the effect of engine cycling on the successive buildup of deposits as aircraft shut down and power up at different intervals. The test facility simulates the pressure and temperature environment of a combustor liner or turbine vane cooling circuit.   The coolant flow temperature reaches 894K (1150 °F) and discharges into a 17atm (250 psi) cavity pressure at a nominal pressure ratio of 1.027. AFRL05 test dust with a 0-5mm size distribution is added to the coolant gas stream at a constant loading of approximately 90 mg/m³. The cooling circuit consists of a double-walled impingement cooling plate and effusion cooling plate with nominal hole sizes less than 1mm. To simulate the effects of cycling, the facility is brought up to the desired operating conditions where the first batch of dust is delivered (4g or 8g).  The facility is then ramped down to ambient conditions.  Following a “dwell” period of 1 hour to 1 day, another batch of dust is delivered once the facility is brought back up to the desired operating condition again.  Test data were acquired for two to four cycles at different dwell intervals and with different dust mass delivered.  Values such as discharge coefficient, pressure ratio, Reynolds Number, and temperature are used to evaluate the effects of dust deposition on the impingement/effusion plate setup.   Dust capture efficiency, cooling hole blockage rate per gram of dust delivered, and surface scans of deposit topology indicate a non-linear response to engine cycling.  Implications for engine operation in dust-laden environments are summarized. 

Presenting Author: Ryan Lundgreen Pratt & Whitney

Presenting Author Biography: Dr. Ryan Lundgreen is a Lead Research Engineer at Pratt & Whitney

Authors:

George Gogidze Ohio State University
Jeffrey Bons The Ohio State University
Ryan Lundgreen Pratt & Whitney