Aerospace & Aeronautical Engineering / Liquid Rocket Thrust Chamber
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LABORATORY 33 · AEROSPACE & AERONAUTICAL ENGINEERING

Liquid Rocket Engine Thrust Chamber and Characteristic Velocity

Measure propellant mass flow rate m_dot, chamber pressure P_c, and thrust F to determine characteristic exhaust velocity c* and thrust coefficient C_F. Explore interactive wind tunnel simulation, flight dynamics, and aerospace engineering telemetry.

AERODYNAMICS · PROPULSION · FLIGHT DYNAMICS

Your virtual aerospace engineering laboratory.

CHAMBER PRESSURE P_C—
FLIGHT & TEST CELL TELEMETRY

Ready to sample with m_dot = 3.0 kg/s.

3.0 kg/s
Propellants: LOX / RP-1 (O/F mass ratio = 2.40)

Adjust m_dot, then execute aerospace trial.

Aeronautical telemetry and flight states are evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity aerodynamic modeling.

Aeronautical assumptions and boundary condition limits

Regenerative coolant heat pick-up increases propellant injection temperature, slightly modifying theoretical c*. Linear regression of chamber pressure against mass flow rate yields a slope c*/A_t = 700.00 kPa/(kg/s) corresponding to c* = 1750 m/s with R^2 > 0.999999.

Aeronautical apparatus & wind tunnel sensors.

Subscale Liquid Rocket Engine Stand (LOX/RP-1)

Regeneratively cooled copper-alloy thrust chamber with coaxial swirl injector head.

High-Pressure Cryogenic Propellant Feed System

Pressurized run tanks supplying liquid oxygen and kerosene at pressures up to 10 MPa.

Coriolis Direct Mass Flow Meters

Measures oxidizer and fuel mass flow rates (m_dot_ox, m_dot_fuel) with 0.1% accuracy.

Flush-Mounted Fast Chamber Pressure Transducers

Measures static chamber pressure P_c and high-frequency combustion roughness.

Multi-Axis Thrust Vector Load Cell Frame

Measures axial thrust force F and side gimbal forces with 0.05% full-scale resolution.

Automated Engine FADEC Test Controller

Sequences cryogenic chilldown, spark torch ignition, and multi-step propellant throttling.

FOLLOW THE METHOD

A reason behind every step.

Measure propellant mass flow rate m_dot, chamber pressure P_c, and thrust F to determine characteristic exhaust velocity c* and thrust coefficient C_F. Standardized parameter settings: 1.5, 2.2, 3.0, 4.0, 5.0, 6.0 kg/s.

01

Cryogenic Chilldown and Purge

Execute gaseous nitrogen purge and liquid oxygen line chilldown until liquid temperature reaches 90 K at injector inlet.

02

Torch Igniter Activation

Ignite methane-oxygen torch pilot flame, verifying optical ignition sense before main propellant valve opening.

03

Main Valve Opening and Low-Throttle Fire

Open main LOX and RP-1 propellant valves to establish baseline firing at m_dot = 1.5 kg/s, stabilizing P_c = 1050 kPa.

04

Systematic Mass Flow Throttling

Throttle propellant flow through m_dot = 2.2, 3.0, 4.0, 5.0, and 6.0 kg/s while maintaining constant oxidizer-to-fuel ratio (O/F = 2.4).

05

Chamber Pressure and Thrust Recording

Record steady-state chamber pressure P_c and thrust F across 2000 samples per channel at each throttle setting.

06

Characteristic Velocity Linear Regression

Plot P_c (kPa) versus m_dot (kg/s), perform linear regression to determine slope c*/A_t, and compute c* from throat area A_t = 0.0025 m^2.

YOUR NOTEBOOK · 0 OBSERVATIONS

Turn measurements into aerodynamic insight.

See a complete example report ↗

Points are your recorded observations. The solid regression line validates Liquid Rocket Thrust Chamber mathematical scaling.

LINEAR REGRESSION FIT · y = mx + b
P_c = \left(\frac{c^*}{A_t}\right) \cdot \dot{m} \implies P_c = m \cdot \dot{m} + b
#Total Mass Flow Rate m_dot (kg/s)Chamber Pressure P_c (kPa)Total Propellant Mass Flow Rate m_dot (kg/s)Combustion Chamber Pressure P_c (kPa)Remove

No readings yet. Execute an aerodynamic trial and record it.

Calculate it yourself.

CHECK YOUR UNDERSTANDING

Explain what the aerodynamic metrics mean.

What fundamental rocket performance parameter evaluates combustion efficiency independently of the supersonic nozzle?

Why do hydrocarbon-fueled liquid rocket engines operate at fuel-rich mixture ratios rather than stoichiometric?

For a throat area A_t = 0.0025 m^2 and chamber gradient c*/A_t = 700.0 kPa/(kg/s), what is the characteristic exhaust velocity c*?

What cooling method circulates cryogenic propellant through channels inside the chamber walls before injection?