UDMH¶
UDMH or Unsymmetrical Dimethylhydrazine ((CH3)2NNH2) became the storable liquid fuel of choice by the mid-1950’s. Development of UDMH in the Soviet Union began in 1949. It is used in virtually all storable liquid rocket engines except for some orbital maneuvering engines in the United States, where MMH has been preferred due to a slightly higher density and performance.
Reference Points¶
UDMH == UnsymmetricDiMethylHydrazine
Hover over column headers to see definitions, values to see alternate units
| Tref | Pref | SG | Cp | dHvap | Visc | Cond | Surf | |
|---|---|---|---|---|---|---|---|---|
| Source | R | psia | g/ml | BTU/lbm-R | BTU/lbm | poise | BTU/hr-ft-R | lbf/in |
| RocketProps | 527.7 | 14.7 | 0.7904 | 0.665 | 250.5 | 5.533e-03 | 0.0919 | 1.407e-04 |
| AFRPL-TR-69-149 | 536.4 | 14.7 | 0.7861 | 0.704 | 233.5 | 4.920e-03 | 0.0909 | 1.375e-04 |
| Aerojet | 527.7 | 14.7 | 0.7904 | 0.665 | 250.6 | 5.534e-03 | 0.0919 | --- |
| Vandenberg | 527.7 | 14.7 | 0.7913 | --- | 245.9 | --- | 0.0947 | --- |
Fluid Properties¶
UDMH == UnsymmetricDiMethylHydrazine
Hover over column headers to see definitions, values to see alternate units
| MolWt | Tc | Pc | SGc | Zc | Tnbp | Tmelt | omega | |
|---|---|---|---|---|---|---|---|---|
| Source | g/gmole | R | psia | g/ml | (-) | R | R | (-) |
| RocketProps | 60.099 | 941.7 | 867.0 | 0.2767 | 0.2985 | 603.9 | 388.7 | 0.34992 |
| AFRPL-TR-69-149 | 60.102 | 941.0 | 867.0 | 0.2750 | 0.3006 | 603.8 | 388.7 | --- |
| Aerojet | 60.099 | 941.7 | 867.0 | 0.2767 | 0.2985 | 603.9 | 388.7 | 0.36186 |
| Vandenberg | 60.099 | 941.4 | 787.7 | 0.2610 | 0.2877 | 606.7 | 387.3 | 0.34300 |
Heat of Vaporization¶
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