Meco Machinery

Machinery components represent rotating equipment that can add or extract energy from the fluid. These components model pumps, turbines, and other rotating machinery with detailed performance characteristics.

Overview

The Meco Rocket Simulator supports 3 different machinery types:

Machinery Type	Purpose	Fluid System	Key Parameters
MachineryPump	Energy addition (pumping)	Liquid	Centrifugal pump geometry
MachineryTurbine	Energy extraction (power)	Gas	Turbine aerodynamics
MachineryNonDynamic	Inertial load	Any	Rotor inertia only

Common Requirements

All machinery components require:

Connection to a Shaft for rotational dynamics
Connection to a Branch for fluid interaction (except MachineryNonDynamic)
Detailed geometric and performance parameters

MachineryPump

Overview

Type: MachineryPump
Purpose: Centrifugal pump for liquid propellant systems
Modeling: Detailed impeller geometry and performance characteristics

Parameters

Connection Parameters:
- name - Component name (string)
- branch - Connected branch name (string)
- shaft - Connected shaft name (string)

Geometric Parameters:
- betaB2 - Outlet blade angle in radians (double)
- r1 - Inlet radius in meters (double)
- r2 - Outlet radius in meters (double)
- b2 - Outlet width in meters (double)
- eRMS - Surface roughness in meters (double)

Design Guidelines

Inlet Radius (r1): Typically 0.03-0.08 m for rocket applications
Outlet Radius (r2): Usually 2-4 times inlet radius for good efficiency
Blade Angle (betaB2): 15-30 degrees (0.26-0.52 radians) for centrifugal flow
Outlet Width (b2): Affects flow rate and pressure rise capability
Surface Roughness (eRMS): 0.000001-0.00001 m for machined surfaces

Example JSON

{
  "name": "LOX Pump",
  "category": 3,
  "type": "MachineryPump",
  "branch": "LOX HP Line",
  "shaft": "LOX Transmission",
  "betaB2": 0.305,
  "r1": 0.05,
  "r2": 0.12,
  "b2": 0.01,
  "eRMS": 0.000001
}

MachineryTurbine

Overview

Type: MachineryTurbine
Purpose: Gas turbine for power extraction from hot gas flow
Modeling: Detailed aerodynamic performance with stator and rotor geometry

Parameters

Connection Parameters:
- name - Component name (string)
- branch - Connected branch name (string)
- shaft - Connected shaft name (string)

Aerodynamic Parameters:
- alpha - Nozzle angle in radians (double)
- beta - Blade angle in radians (double)
- admissionRatio - Admission ratio 0-1 (double)

Geometric Parameters:
- rTip - Tip radius in meters (double)
- rotorH - Rotor height in meters (double)
- rotorC - Rotor chord in meters (double)
- statorA - Stator area in m² (double)
- statorO - Stator opening in m² (double)

Operating Parameters:
- omega - Rotational speed in rad/s (double)
- gamma - Heat capacity ratio (double)
- t - Temperature in Kelvin (double)
- rS - Specific gas constant in J/kg·K (double)

Design Guidelines

Nozzle Angle (alpha): 60-75 degrees (1.05-1.31 radians) for optimal efficiency
Blade Angle (beta): 30-45 degrees (0.52-0.79 radians) for impulse turbines
Admission Ratio: 0.5-1.0, partial admission reduces efficiency but enables control
Speed Parameter (omega): Match to shaft system for optimal power extraction
Gas Properties: gamma ≈ 1.3-1.4 for combustion products, rS depends on gas composition

Example JSON

{
  "name": "LOX Turbine",
  "category": 3,
  "type": "MachineryTurbine",
  "branch": "LOX Stator Nozzle",
  "shaft": "LOX Transmission",
  "alpha": 1.2740903539558606,
  "beta": 1.222,
  "rTip": 0.166,
  "rotorH": 0.02,
  "rotorC": 0.03,
  "statorA": 0.00631,
  "statorO": 0.00246,
  "admissionRatio": 0.9,
  "omega": 1391,
  "gamma": 1.398,
  "t": 1050,
  "rS": 2270
}

MachineryNonDynamic

Overview

Type: MachineryNonDynamic
Purpose: Non-rotating machinery that adds inertial load to shaft systems
Modeling: Pure rotational inertia without fluid interaction

Parameters

Connection Parameters:
- name - Component name (string)
- shaft - Connected shaft name (string)

Inertial Parameters:
- rotorRadius - Rotor radius in meters (double)
- rotorLength - Rotor length in meters (double)
- rotorDensity - Rotor material density in kg/m³ (double)

Design Guidelines

Material Density:
- Steel: ~7850 kg/m³
- Aluminum: ~2700 kg/m³
- Titanium: ~4500 kg/m³
Sizing: Consider rotational inertia effects on system dynamics
Applications: Flywheels, generators, auxiliary equipment

Example JSON

{
  "name": "Generator Load",
  "category": 3,
  "type": "MachineryNonDynamic",
  "shaft": "Main Shaft",
  "rotorRadius": 0.15,
  "rotorLength": 0.3,
  "rotorDensity": 7850
}

Turbomachinery Design Principles

Pump Design

Specific Speed: Optimize impeller geometry for required flow and head
NPSH Requirements: Ensure adequate suction performance to avoid cavitation
Efficiency: Target 75-85% efficiency for rocket pump applications
Structural Integrity: Consider stress limits at high rotational speeds

Turbine Design

Velocity Ratios: Optimize blade speed to gas velocity for maximum efficiency
Stage Loading: Balance pressure ratio per stage with efficiency
Cooling: Consider thermal limits and cooling requirements
Partial Admission: Use for control but expect efficiency penalties

System Integration

Speed Matching: Match pump and turbine speeds through gear ratios
Power Balance: Ensure turbine power exceeds pump power requirements
Transient Response: Consider rotational inertia effects on startup/shutdown
Control Strategy: Integrate with control systems

Performance Modeling

Pump Performance

Head-flow characteristics based on impeller geometry
Efficiency curves accounting for losses (hydraulic, volumetric, mechanical)
NPSH requirements for cavitation avoidance
Power consumption calculations

Turbine Performance

Aerodynamic performance based on velocity triangles
Stage efficiency modeling including profile, secondary, and tip clearance losses
Partial admission effects on performance
Heat transfer and cooling considerations

Common Applications

Main Engine Pumps: High-pressure propellant pumps for main combustion chamber
Gas Generator Turbines: Power extraction from gas generator exhaust
Preburner Turbines: Power for staged combustion cycle engines
Auxiliary Drives: Generators, hydraulic pumps, other accessories
Control Systems: Variable geometry turbines for engine control

Overview

Common Requirements

MachineryPump

Overview

Parameters

Design Guidelines

Example JSON

MachineryTurbine

Overview

Parameters

Design Guidelines

Example JSON

MachineryNonDynamic

Overview

Parameters

Design Guidelines

Example JSON

Turbomachinery Design Principles

Pump Design

Turbine Design

System Integration

Performance Modeling

Pump Performance

Turbine Performance

Common Applications

See Also