Similarity Studies for Air Data Probes New Standard – AS5562 Coupled Heat and Mass Transfer Effects Guilherme da Silva ATS4i Aero-Thermal Solutions for Industry gasilva@ats4i.com.br SAE AC-9C Aircraft Icing Technology Committee Meeting #57 October 8th-10th 2010 - Portland, OR Introduction SAE AIR1168/4 Model Coupled Heat and Mass Transfer Effects of Impingement and Ice Crystals Conclusions and Possible New Directions Introduction Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Objectives To present simplified analytical models To discuss the model assumptions with broader audience To present results generated by heat transfer similarity studies To collaborate with AS5562 works Presentation focus Heat and mass transfer aspects of thermal ice protection of probes ONLY Aspects of similitude tunnel-flight when testing heated probes Main reason Knowledge and experience of the author on heat transfer NO focus on probes design parameters definition at all NO focus on failure modes and effects NO focus on absolute results! Only comparative. Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next LWC vs. Total Air Temperature (TAT) 5.00 LWC CM FAR25 AP C 4.50 Test #1 BS G2.135 4.00 Test #2 BS 2G.135 SUPERCOOLED LIQUID ONLY!! LWC IM FAR 25 Ap C extended 3.50 LWC [g/m3] 3.00 LWC IM FAR 25 AP C EASA Conditions (M=0.3 e 0.4 @ SL) SAE AS5562 (Table 2) 2.50 2.00 1.50 1.00 0.50 0.00 -40.0 -30.0 -20.0 -10.0 TAT [C] 0.0 10.0 20.0 Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next SAE AS5562 (Draft) Ice and Rain Qualification Standards for Air Data Probes Under development Studies based on version “AS5562 draft 3-14-12.doc” Used only two types of information from AS5562 in present study: Conditions – Supercooled Liquid, – Ice Crystals – Mixed Phase Icing – Rain Testing – Operational limitations (similarity guidelines) Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Heat and Mass Transfer Tunnel-Flight Similarity Flow Reynolds number (Re) Stanton (St) Mach (M) Total Water Collection Water catch high beta tunnel water mass flux Droplets inertia parameter high beta not important Remaining water runback water management Heat and Mass Transfer Reynolds number (Re) Stanton (St) Stanton (St) analogy Stanton mass (St_m) Convective Heat Transfer driven force (DT) Convective Mass Transfer driven force (mass fractions) Conclusions/Next Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Tunnel Condition Adjustment (as per AS5562 3-14-12 draft) : Altitude Limitation TAStest = TASref TATtest = TATref SATtest = SATref But ice crystals still need a model or criteria Airspeed Limitation: TATtest = TATref LWCtest = LWCref * TASref / TAStest IWCtest = IWCref * TASref / TAStest Static Air Temperature Limitation: TATtest = TATref LWCtest = LWCref * TASref / TAStest IWCtest = IWCref * TASref / TAStest Applicability range limits need to be studied SAE AIR1168/4 Model Introduction SAE AIR1168/4 Heat and Mass Model Based on AIR1168/4 Assumptions Zero-Dimensional (lumped analysis) Collection Efficiency b = 0.85 Surface fully wet F=1 Impingement area = total area Temperatures above 0°C Thin Water Film Running wet OR Fully evaporative Effects considered: – – – – – Convection Water Vaporization Water Impingement No ice fusion effect No conduction or other heat lossess Impingement/Crytals Conclusions/Next Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next CFD++ results Plane Y=0 AOA=0°C Side-Slip=0ºC Collection Efficiency can be used as input Of 1D or 2D more advanced models HOWEVER, present study ASSUMED conservative value of b=0.85 Plane Z=0 Plane Z=0.025 Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Results of Model Based on AIR1168/4 For surface at 0°C Supercooled liquid water only Conclusions/Next Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Study of Similarity Rules proposed by SAE AS5562 Altitude Limitation Alt=Atl(M) Keep TAS, TAT,SAT, Tsup Keep TAS, TAT,SAT, q0 with Tsup SAT Mach LWC CM Alt [kft] -30.0 0.440 0.125 20.0 -30.0 0.440 0.125 5.0 -30.0 0.440 0.125 5.0 Pamb [Pa] V [m/s] 46564 137.5 84449 137.5 84448.9 137.5 CAS 200 262 262 Tsup q0/s0 [K] Trec [K] [W/in2] q0 [W] 273.15 251.6 7.47 353 273.15 251.6 9.48 449 269.35 251.6 7.46 353 Pamb [Pa] V [m/s] 46564 137.5 90771 90.0 90875 90.0 90875 90.0 CAS 200 271 178 178 Tsup q0/s0 [K] Trec [K] [W/in2] q0 [W] 273.15 251.6 7.47 353 273.15 246.8 8.30 393 273.15 251.6 7.01 332 274.22 251.6 7.46 353 Pamb [Pa] V [m/s] 48548 134.7 91389 83.9 91389 83.9 CAS 200 272 169 Tsup q0/s0 [K] Trec [K] [W/in2] q0 [W] 273.15 241.3 10.03 475 273.15 241.3 9.29 440 275.02 241.3 10.04 475 TAS and Altitude Limitation Alt=Atl(M) Keep Mimp and Tsup Keep Mimp, TAT, Tsup Keep Mimp, TAT, q0 with Tsup SAT Mach LWC CM Alt [kft] -30.0 0.440 0.125 20.0 -30.0 0.288 0.191 3.0 -25.2 0.285 0.191 3.0 -25.2 0.285 0.191 3.0 SAT and Altitude Limitation Alt=Atl(M) Keep TAT, Mimp, Tsup Keep TAT, Mimp, q0 with Tsup SAT Mach LWC IM Alt [kft] -40.0 0.440 0.187 19.0 -35.0 0.271 0.301 2.8 -35.0 0.271 0.301 2.8 Coupled Heat and Mass Transfer Introduction SAE AIR1168/4 Heat and Mass Simple Evaporative Cooling Model Assumptions Zero-Dimensional (lumped analysis) Collection Efficiency b = 0.85 Surface fully wet F=1 Temperatures above 0°C Thin Water Film Running wet OR Fully evaporative Effects considered: – Convection – Water Vaporization – No water Impingement effect – No conduction or other heat lossess – No ice fusion effect Impingement/Crytals Conclusions/Next Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Coupled Heat and Mass Transfer (Spalding, 1962) m evap gm Bm Bm q surf gh 1 cmix (Trec Tsurf ) g m hlv gh m H 2 O ,S m H 2 O , G m H 2 O ,S 1 gm * Bm gm ln(1 Bm ) 2 2 gm g Le 3 m Le 3 gh h cp mH 2 O ,i pvap ,i 1.61 pamb 0.61 pvap ,i Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Graphical Method of Solution M evap gm Bm Only liquid phase considered. Need extension for ice crystals and mixed phase Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Study of Similarity Rules proposed by SAE AS5562 Power Power Density Density Paltitude [W/in2] [W/m2] [kft] P [Pa] SAT V [m/s] Mach Trec [C] Tsup [C] Altitude Limitation Alt=Atl(M) 12.0 12.0 18600 18600 20.0 5.1 -30.0 -30.0 46564 84076 0.44 0.44 TAS and Altitude Limitation Alt=Atl(M) 12.0 18600 20.0 -30.0 137.5 137.5 -21.5 -21.5 7.1 3.4 46564 0.44 137.5 -21.5 7.1 -30.0 -25.1 90771 90877 0.29 0.29 90.0 90.0 -26.4 -21.5 7.8 9.9 SAT and Altitude Limitation Alt=Atl(M) 12.0 18600 20.0 -40.0 12.0 18600 2.8 -35.1 46564 91383 0.44 0.27 134.7 83.9 -31.9 -31.9 4.0 6.5 12.0 12.0 18600 18600 3.0 3.0 Effects of Impingement and Ice Crystals Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Modified Evaporative Cooling Model Assumptions Zero-Dimensional (lumped analysis) Collection Efficiency b = 0.85 Surface fully wet F=1 Temperatures above 0°C Thin Water Film Running wet OR Fully evaporative Additional Effects considered (0thers kept): – Water Impingement effect – Ice fusion effect Ice Crystals and Mixed Phase – Low Convection in Enclosed Space inside Probe Tube – Internal Probe Ambient Temperature -5 ºC (Arbitrary, need thermal analysis) Conclusions/Next Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Envelope Study with Modified Evaporative Cooling Model For surface at 0°C Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Study of Similarity Rules proposed by SAE AS5562 LWC [g/m3] Beta Power Power Density Density Paltitude [W/in2] [W/m2] [kft] Altitude Limitation Alt=Atl(M) 0.125 0.85 12.0 18600.0 0.125 0.85 12.0 18600.0 TAS and Altitude Limitation Alt=Atl(M) 0.125 0.85 12.0 18600.0 0.191 0.85 12.0 18600.0 0.191 0.85 12.0 18600.0 SAT and Altitude Limitation Alt=Atl(M) 0.125 0.85 12.0 18600.0 0.201 0.85 12.0 18600.0 P [Pa] SAT Mach V [m/s] Mimp Trec [C] [g/(s*m2)] Tsup [C] 20.0 5.1 -30.0 -30.0 46564 84076 0.44 0.44 137.5 137.5 -21.5 -21.5 14.6 14.6 5.3 1.8 20.0 3.0 3.0 -30.0 -30.0 -25.1 46564 90771 90877 0.44 0.29 0.29 137.5 90.0 90.0 -21.5 -26.4 -21.5 14.6 14.6 14.6 5.3 5.2 7.7 20.0 2.8 -40.0 -35.1 46564 91383 0.44 0.27 134.7 83.9 -31.9 -31.9 14.3 14.3 1.6 3.4 Conclusions and Possible New Directions Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Conclusions Simple Evaporative Cooling Model does provide qualitative results that allow trade-off and similarity studies Modified Evaporative Cooling Model (with ice crystals and water catch) allows: Analysis of similarity flight-tunnel regarding heat transfer effects Comparison between air data probe standards/documents conditions in terms of heat load and water catch The similarity proposed by AS5562 must be complemented by a Thermal Heat Load Analysis, what eventually may lead to probe heater decrease in tunnel Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Suggested Next Steps To perform a thermal analysis to assess the temperature inside the air data probe tube, which must include thermal radiation To study the transient ice melting problem inside probe tube with supercooled water, ice crystals and mixed phase To predict the 3D impingement over the probe To estimate the 3D water runback (film, beads, rivulets) movement and the surface wetness factor To correlate 3D results in order to used in simple analytical 0-D models Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next ATS4i Code convection ATS4i Code overall ATS4i Code Plan compare with 2D code results and test data Need an application case and test data! ATS4i Code end of water film Introduction SAE AIR1168/4 Generic Probe Results Need test data for validation! Heat and Mass Impingement/Crytals Conclusions/Next Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Conclusions/Next Collection Efficiency Results from CFD++ Plane Y=0 Collection Efficiency on Surface Generic Probe Results Plane Z=0 Plane Z=0.025 Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Evaporation Heat Flux Results after Post-Processing Generic Probe Results Full Evaporative Heat Flux Average 2.6 W/in2 Typical Power Density 10 W/in2 Conclusions/Next Introduction SAE AIR1168/4 Heat and Mass Impingement/Crytals Cp Sample Results from CFD++ Generic Probe Results. Sample of Results. Conclusions/Next Thank you ! Contact: Guilherme da Silva gasilva@ats4i.com.br Presentation References Certification/Qualification Documents Regulations – FAR 25 and TSO C16a Standards – SAE AS390, SAE AS393, SAE AS403A, SAE AS8006, BSI 2G.135, MILT-5421B, MIL-T-5421A, MIL_P-83206, MIL-P-25632B SAE Standard in preparation SAE AS5562 (Draft) - Ice and Rain Qualification Standards for Airdata Probes AC-9C, Air Data Probe Standards Panel, SAE, 2006 (presentation) AC-9C, Design Requirement Cross Reference List Rev6, SAE (excel spreadsheet) SAE , SAE Aerospace Applied Thermodynamics Manual, “Ice, Rain, Fog, and Frost Protection”, SAE AIR1168/4, Proposed Draft, 2006 Spalding, D. B., “Convective Mass Transfer, an Introduction”, McGraw– Hill, New York, 1963. Duvivier, E. (EASA) “Flight Instrument External Probes”, 1st SAE Aircraft & Engine Icing International Conference, Seville, 2007 (conference presentation) Further Reading Mason, J., “The Physics of Clouds”, 2nd Ed., Claredon Press, Oxford, 1971 (book) Johns, D. (TC Canada), “Future Rulemaking – Ice Protection Harmonization Working Group –Update”, 1st SAE Aircraft & Engine Icing International Conference, Seville, 2007 (conference presentation) Bernstein, B., Ratvasky , T. P., Miller, D.R., “Freezing Rain as an in-Flight Icing Hazard”, NASA TM--2000-210058, NCAR, Colorado, June (NASA Report) Jeck, R. K., “Representative Values of Icing-Related Variables Aloft in Freezing Rain and Freezing Drizzle”, DOT/FAA/AR-TN95/119, Federal Aviation Administration, U.S. Department of Transportation,1996 (FAA Technical Note) Jeck, R. K., “Advances in the Characterization of Supercooled Clouds for Aircraft Icing Applications”, DOT/FAA/AR-07/4, Federal Aviation Administration, U.S. Department of Transportation,2008 (FAA Report) European Aviation Safety Agency (EASA), ETSO C16 update , Terms of Reference, ToR Task number ETSO.009, Issue 1, August 31, 2009 (EASA document) Ice Protection Harmonization Working Group (IPHWG), Tasks 5 & 6 Working Group Report, October 2006, Rev A March 2007 (IPHWG report) Ice Protection Harmonization Working Group (IPHWG), “Task 2 Working Group Report on Supercooled Large Droplet Rulemaking”, December 2005 (IPHWG report)