Transcript Hydraulic System Design Requirements Agreement 2 September

IV
EELV
A Thermal Hydraulic Model
for Expendable Launch
Vehicles
Michael Berglund
Delta IV Launch Vehicle Development
May 16-17, 2000
Created by
Michael Berglund
1
IV
EELV
Outline
Point 1 - Correlation with Test Data
Rocketdyne
Thermal analysis
DT-1 RCN
Point 2 - Design Tool, Test Transient Conditions
Point 3 - Common Modeling System
Rocketdyne
Controls group
Point 4 - Good Customer Support
New Parts Specified
Modeling Hydraulic Systems Using EASY5
Summary of EASY5 Process
Created by
Michael Berglund
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IV Easy5 Model of RS-68 Hydraulic System
EELV
Heat Transfer Analysis: EJ Reott
 ACTUATOR
VERIFICATION
 VM fluid output temp
TF2VM
 FO fluid output temp
(corrected)
TF2
 Matches MHI Data
(error +/- 3.7%)
Created by
Michael Berglund
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IV Easy5 Model of RS-68 Hydraulic System
EELV
Heat Transfer Analysis: EJ Reott
 LINE SEGMENT
VERIFICATION
 Heat transfer from fluid to
wall (BTUH)
QFPI
 Heat transfer from fluid to
wall (corrected)
QFPI11
 Wall temp
TWPI
 Wall temp (corrected)
TWPI11
 Matches Calculation
(error +/- 0.4%)
Created by
Michael Berglund
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EELV
Fluid Temp Rise Across Orifice
TVC1, TVC2, RCN
 EASY5 model: oil temp
rise across orifice results:
 T = 76°F
 Hand Calculations: Oil
temp rise across orifice
(same conditions) results:
 T = 75.9°F
Created by
Michael Berglund
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IV
EELV
Created by
Michael Berglund
Fluid Temperature Rise In Flight
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EELV
Development Test Models (major assumptions)
 Development Test Models
 DT_RCN (boundary conditions, spring force)
 DT_TVC (boundary conditions, spring + constant force)
 DT_Breadboard (valves simulating flow demand for all actuators, single
valve representing all 4 engine valves)
 DT_System (TVC, RCN actuators included, single valve representing all 4
engine valves)
 Hydraulic_System (same as DT_System but with engine valves from
Rocketdyne)
Created by
Michael Berglund
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IV
EELV
Created by
Michael Berglund
EASY5 DT-1 RCN Model
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EELV
RCN Velocity and Stroke
Stroke & Velocity vs. Time
20.0
Velocity Transducer
15.0
LVDT-in.
Calculated LVDT
Stroke-in, Velocity-in/sec
10.0
5.0
0.0
-5.0
-10.0
-15.0
-20.0
0.0
0.5
1.0
1.5
2.0
2.5
Time (sec)
DT-1 RCN
Created by
Michael Berglund
EASY5
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IV
EELV
Force Data
3000
Force
2000
Force (lb)
1000
0
-1000
-2000
-3000
0.0
0.5
1.0
1.5
2.0
2.5
Time (sec)
DT-1 RCN
Created by
Michael Berglund
EASY5
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IV
EELV
DT-1 RCN & Model Correlation
Force Data
3000
Force
2000
Force (lb)
1000
0
-1000
-2000
-3000
0.0
0.5
1.0
1.5
2.0
2.5
Time (se c)
Spring Characteristics
of Air Spring
3000
2000
Force (lbs)
1000
0
-1000
-2000
-3000
-6.0
-5.0
-4.0
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
Stroke (in)
Stroke vs. Time
10.00
LVDT-in.
Stroke-in, Velocity-in/sec
5.00
0.00
-5.00
-10.00
0.0
0.5
1.0
1.5
2.0
2.5
Time (se c)
DT-1 RCN
Created by
Michael Berglund
EASY5
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EELV
Common Modeling System
 Rocketdyne
 Received and integrated
Rocketdyne’s EASY5 model
into CBC EASY5 model
 Controls Group
Created by
Michael Berglund
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EELV
New Components
 Found in New EASY5 Library
 AD (accumulator with an inlet and outlet), Qin, Qout for
both fluid and gas, EFX heat flux
 PI - Pipe with heat flux
 VO - Volumes with heat flux
Created by
Michael Berglund
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EELV
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New Accumulator
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EELV
EASY5 New Components
 New Parameters: EFX and QIN
 EFX defines additional energy
flux into the volume wall. EFX
units are BTUH/in2.
 QIN defines additional heat
generated internally within the
fluid. QIN units are BTUH
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Michael Berglund
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EELV
Conclusions
 EASY5
 Test correlation
 Design tool, test transient conditions
 Common modeling system
 New parts specified
 Recommendation: Continue to use EASY5 to model
hydraulic system
Created by
Michael Berglund
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EELV
Modeling Hydraulic Systems Using
EASY5
 EASY5 Process
 Building a Model
Created by
Michael Berglund
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EELV
EASY5 Process
 Define system and the EASY5 model objective
 Build Model by Placing and Linking the
Components in the Correct Sequence (use only
default or port connection method)
 Create an Executable File
 Find an Initial Operating Point (All Time
Derivatives = Zero)
 If the Model Equations Converge, Run a
Simulation
 Plot Any Output As a Function of Time
Created by
Michael Berglund
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EELV
Building the Model
 Start with simple foundation model, ie, valves for actuators,
volumes instead of accumulators, no tabular functions,
average values
 Run to see if results make sense, check with other team
members (in the ball park values)
 Build on model, make more complex if preliminary model
checks out
 Make thermodynamic model as simple as reasonably
possible because of potentially large simulation times
Created by
Michael Berglund
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IV
EELV
Actuators Approximated by
Metering Valves
Similar to Breadboard Development Test
set-up
Created by
Michael Berglund
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EELV
Created by
Michael Berglund
Model of TVC Actuator
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EELV
Created by
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EELV
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EELV
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