RPA: Tool for Rocket Propulsion Analysis
Assessment of Delivered Performance of Thrust Chamber Alexander Ponomarenko
[email protected] http://www.propulsion-analysis.com March 2013 (v.1)
Abstract Rocket Propulsion Analysis (RPA) is a multi-platform analysis tool intended for use in conceptual and preliminary design (design phases 0/A/B1). This report describes a numerical models and computation techniques implemented in RPA to estimate the delivered performance of thrust chambers.
Contents Nomenclature..........................................................................................................................3 Introduction.............................................................................................................................4 Numerical Model.....................................................................................................................4 Delivered Performance.......................................................................................................4 Correction Factors..............................................................................................................6 Finite Rate Kinetics in the Combustion Chamber..........................................................6 Boundary Layer (Friction) Loss......................................................................................7 Divergence Loss...........................................................................................................10 Multi-Phase Flow Loss.................................................................................................12 Built-In Assessment..........................................................................................................13 Finite Rate Kinetics in the Nozzle................................................................................13 Finite-Area Combustion Chamber................................................................................13 Interzonal Losses.........................................................................................................15 Nozzle Flow Separation...............................................................................................16 Thrust Throttling ..........................................................................................................17 Application in RPA and RPA SDK.........................................................................................19 References............................................................................................................................20
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Nomenclature A
cross-sectional area, m2
̄ A
̄ = A / At relative cross-sectional area, A
̄ F
̄ =A / m˙ , (s·m2)/kg specific cross-sectional area, F
c*
characteristic velocity, m/s
Is
specific impulse, m/s
Cf
thrust coefficient
p
pressure, Pa
T
temperature, K
w
velocity, m/s
M
Mach number
λ
characteristic Mach number
density, kg/m3
m˙
mass flow rate, kg/s
Re
Reynolds number
δ**
boundary layer momentum thickness
η
dynamic viscosity, kg/(m·s)
ξ