SAE AIR1168/4 Model

Report
Similarity Studies for Air Data
Probes New Standard – AS5562
Coupled Heat and Mass Transfer Effects
Guilherme da Silva
ATS4i Aero-Thermal Solutions for Industry
[email protected]
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
[email protected]
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)

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