FAR

Fixed Airframe Rocket

Pathfinder 1/2

in use: general testing vehicle

Because the math behind waterrockets is quite complicated, we decided to build the pathfinder test-vehicle FAR (fixed airframe rocket).
As the name suggests, it is fixed to the ground, so not quite a "rocket" yet. But it is basically an early prototype of the planned Poseidon-Rocket, which is held down by load cells.
This enables us to measure the thrust curve and change in mass over time. With that data we should be able to build a mathematic model.

Block 4 Specifications

Height

1710 mm

Diameter

74 mm

Dry Mass

2750 g

Propellant

Water, 4 kg

Pressurant

Air, 3 MPa

max. Thrust

102 N / 10.4 kgf

tot. Impulse

220 Ns

Apogee

no lift off

Test Results

We conducted multiple thrust test, with FAR mounted on loadcells to measure the force.
Later tests used higher and higher pressures, up to 33bar. There were different variations of the tanks, valves and nozzle, for example the new carbon composite (opposed to previous PVC) tanks used in the latest tests.

FAR Block 3

PVC tanks, C-D nozzle, 30+ bar rated valve

CSV Download

Chart by Visualizer

FAR Block 4

Carbon composite propellant tank, PVC pressurant tank, C-D nozzle, 30+ bar rated valve

CSV Download

Chart by Visualizer

FAR High Pressure Tests

27 Oct 2021 | By Finn | Launches and Tests

Over the summer we tested the FAR prototype under higher pressure. For that purpose we bought a 300bar air cylinder and regulator.We conducted the high pressure tests to research thrust and burntime under flying pressures of about 30bar and to check the experimental data against our simulation. Hydrostatic tests At first, to verify that the PVC tanks of the FAR prototype won't explode under the high pressure - the tanks are rated for 10bar, we want to use 30bar - we conducted multiple hydrostatic tests.Hydrostatic - as the name suggests - means we fill the test tank completely with water ...