Actions

Pressure Fed Gas Engine

From Unofficial Stationeers Wiki

Kit (Pressure Fed Gas Engine)
ItemKitPumpedLiquidEngine.png
Fabrication
Created with Rocket Manufactory (Tier One)
Cost 60000 Energy, 20g Steel, 5g Electrum, 20g Invar, 10g Constantan
Temperature
Flashpoint 373K (100°C)
Autoignition 573K (300°C)
Other properties
Paintable Yes
Stack Size 1
Prefabs
Prefab Hash -121514007
Prefab Name ItemKitPressureFedGasEngine
Pumped Liquid Engine
StructurePumpedLiquidEngine.png
Operation
Base Power Usage 10W
Rocket Mass Contribution 500kg
Max Thrust 40.3kN
Efficiency 96%
Exhaust Velocity 3.86km/s (Isp: 394s)
Contruction
Total cost 5x Insulated Pipe, 4x Steel Sheets
Constructed from Kit (Pressure Fed Gas Engine)
Other properties
Paintable Yes
Prefabs
Prefab Hash -624011170
Prefab Name StructurePressureFedGasEngine

Description

"Inefficient but very powerful, the Pressure Fed Gas Engine moves gas from each of its two inputs based on the pressure of the input pipes. Control the mixing ratio of fuel by tweaking the input pressures to a target 2:1 mix of Liquid Volatiles to Liquid Oxygen gas. Chilling propellant gasses or using Liquid Nitrous Oxide as an oxydizer will result in even higher trhust outputs."
- Stationpedia

Comparison

Rocket Engines give you their max output in kN with this you can calculate what they can reasonably carry into orbit depending on the planet or moon you are on. Force = Mass * Acceleration. Acceleration is equal to the planet's gravity, Mass is given in kg per part of the rocket, and Force is kN. If your thrust force listed below is less than the weight of the rocket in kN then you will not even take off. It is better to have a thrust much higher than the weight of the rocket or else you risk running out of fuel on launch and on landing.

Liquid propellants bring greater efficiencies. Using Nitrous Oxide as oxidizer provides excessive thrust values. Keep in mind that N2O fuel mix is 1.9375 times heavier while thrust boost is around 1.5-1.7. Engine efficiency determines "bonus" thrust multiplier, meaning engine with higher efficiency will give more thrust consuming same amount of fuel. Thus using liquid engines is more favorable if one can cool fuel down, moreover Pressure Fed Engines consume fuel inversely proportional to its temperature. On the other hand if Volatiles and Oxygen are in excess (e.g. farm on Vulcan) is may be much easier to opt for Pressure Fed Gas Engine. It will provide ~40kN at 20°C.

Name Base Power Usage Rocket Mass Contribution Max Thrust Real Max Thrust Efficiency Exhaust Velocity
Using O2 Using N2O
Pressure Fed Gas Engine 10W 500kg 40,3kN 61,0kN 41,9kN[1] 96% 3,86km/s (Isp: 394s)
Pumped Gas Engine 200W 500kg 16,2kN 16,5kN 24,5kN 100% 4,02km/s (Isp: 411s)
Pumped Liquid Engine 200W 500kg 17,6kN 18,7kN 31,3kN 140% 5,47km/s (Isp: 559s)
Pressure Fed Liquid Engine 20W 500kg 29,2kN 43,4kN - 38,1kN 74,5kN - 61,3kN 160% 6,18km/s (Isp: 631s)
Update 0.2.4726.21691 - 18/01/2024 Rocket_Engines

Controversy

This engine is controversially discussed among stationeers as possibly beeing the best choise of engine, but it depends on the use case. If using Liquid Nitrous Oxide as an oxydizer, it will most likely liquify in the tanks andor pipes and make your rocket go boom.

Usage

To make the rocket work, use 2 Volume Pumps, 2 Pipe Analyzers and a IC10 Script to keep the Pressure up. Maybe don't build this rocket if it's your first one. The ideal pressure of the intake pipes is not a fixed number; it depends on the size and weight of your rocket and needs to be determined either mathematically or by trial and error.

Control

Setup that proves to work nicely:
define ATMOSMODEVOLPRESSURE 10000

define ATMOSMODEOXYPRESSURE 5000

define FULLMODEVOLPRESSURE 54000

define FULLMODEOXYPRESSURE 27000

define LOWTHROTTLETHRESHOLD 60 # the rocket is possibly landing when Throttle is lower that

Define Constants and Variables:


Pressure Settings: Determine and define the pressure values for both atmosphere and full mode. These will be used to control the pressure of the gases in the system.
Engine Parameters: Identify key parameters such as throttle thresholds and engine hash identifiers.

Initialize Components:
Enable Components: Turn on the necessary components like Volume Pumps and Pipe Analyzers to ensure they are functioning correctly.
Set Up Variables: Initialize variables for tracking current values like thrust-to-weight ratio and throttle.

Monitor Engine State


Measure Thrust-to-Weight Ratio: Continuously check the current thrust-to-weight ratio to determine the operating state of the rocket.
Throttle Levels Monitor the current throttle level to determine if the rocket is under high or low throttle conditions.

Throttle


Low Throttle Condition If the throttle is below a certain threshold, this usually indicates the rocket might be landing or in a low-power state. Adjust the pressure settings accordingly.

High Throttle Condition For high throttle, maintain or adjust the pressure settings to ensure optimal performance and efficiency.

Pressure Adjustment Logic


Atmosphere Mode Set the pressure values for gas inputs to match the atmospheric conditions. This involves checking if the pressure is too high or too low and adjusting the volume pumps accordingly.
Full Mode When the rocket is in full power mode (e.g., during space travel), adjust the pressures to higher values to optimize thrust.

Control Loop


Continuous Monitoring The script should continuously loop, checking and adjusting the pressure settings based on the current state of the rocket. This ensures the rocket operates efficiently throughout its journey.

Handling Pressure Adjustments


Adjust Pumps: Depending on the current pressure readings, activate or deactivate pumps and set their volumes to reach the desired pressure levels.

Update Settings: Make real-time adjustments to the pump settings to maintain the appropriate pressure levels for both atmosphere and space conditions.

Data Network Properties

Click here to see/hide all the data network properties

Input Data (Write)

Parameter Name Data Type Value Description
On Boolean 0 Turns the device off.
1 Turns the device on.
Setting int A variable setting that can be read or written, depending on the device.
Throttle int Increases the rate at which the machine workes (range: 0-100)
Update 0.2.4726.21691 - 19/01/2024 /Data_Network

Output Data (Read)

Parameter Name Data Type Value Description
Power Boolean Can be read to return if the device is correctly powered or not, set cia the power system, return 1 if powered and 0 if not.
Error Boolean 1 if device is in error state, otherwise 0.
Pressure int The current pressure reading of the device.
Temperature int The current temperature reading of the device.
Setting int A variable setting that can be read or written, depending on the device.
RatioOxygen int The ratio of Oxygen in device atmosphere.
RatioCarbonDioxide int The ratio of Carbon Dioxide in device atmosphere.
RatioNitrogen int The ratio of Nitrogen in device atmosphere.
RatioPollutant int The ratio of Pollutant in device atmosphere.
RatioVolatiles int The ratio of Volatiles in device atmosphere.
RatioVolatiles int The ratio of water in device atmosphere.
Maximum int Maximum setting of the device.
Ratio int Context specific value depending on device, 0 to 1 based ratio.
Ratio Boolean The current state of the device, 0 for off, 1 for on.
RequiredPower int Idle operating power quantity, does not nevessarily include extra demand power.
TotalMoles int Returns the total moles of the device.
RatioNitrousOxide int The ratio of Nitrous Oxide in device atmosphere.
PrefabHash int The hash of the structure.
Combustion Boolean The assess atmosphere is on fire. Returns 1 if atmosphere is on fire, 0 if not.
Throttle int Increases the rate at which the machie works (range: 0-100)
ReferenceId Unique Reference Identifier for this object.
PassedMoles int The number of moles that passed through this device on the previous simulation tick.
Update 0.2.4726.21691 - 19/01/2024 /Data_Network

Build States

Click here to see/hide all the build states
  1. N2O must be much hotter to avoid condensing therefore decreasing pumping rate