PSAS Propulsion Team is building a reciprocating piston pump for liquid-fueled motors.

Pump Description

The pump under development uses OTS double-acting hydraulic cylinders with a high-pressure gas against the top side to pressurize the fuel and a spring return attached to the cylinder rods to refill after each discharge cycle. I should really take some illustrative pictures so that this site provides useful information.

News/Updates

News and Updates

2012-02-14 - Digitalia Ordered

To-Do

wire sensors and solenoids
write C code
test code
embed code
Test 1.

Pump System Parameters

Parameters identified so far in the pump system are as follows:

Component Sourcing

To control the gas solenoids, we need to acquire relays, optoisolators and proximity sensors so that the pump controller knows where in its cycle it is at any point. All part numbers are for the Digi-Key catalogue.

Requirements: 2 Hz operation of relays, piston throw = 3.5 inches.

H11L1-MQT-ND, an optocoupler.
425-2616-5-ND, a distance sensor (10 cm, in excess of requirements)
PB365-ND, a relay. Rated for 1800 ops/hr, which translates to .5 Hz. However, not rated in ops/second, so it may be possible to drive them fast for a brief period of time. Keith may have suggestions on this topic. Haven't found anything better on Digi-Key and am tired of looking. Getting ready to order these. They're cheap, so we can fry them and replace later.

Parameter Relationships

$F_{op} = A_F * P_F = A_S * P_S \Rightarrow D_S = \sqrt{\frac{P_F}{P_S} * D_F^2}$

This, however, is a lie. There are frictional and spring forces working against the pump. In the part of the pump's cycle where the steam side cylinder volume is expanding, the force required to drive fuel is approximately:

$P_S * D_S^2 = P_F * A_F + F_f + k\Delta x$

$\emph{lg} = \frac{4 * \overset{\centerdot}{m}}{\pi * D_F^2 * \emph{f} * \rho_K}$

$\left[P_{H_2O\emph{g}} * D_S^2 = P_F * D_F^2 \right] < \sigma_{allowed} * D_{rod}^2$

Random Thoughts

See the cooling page for discussion on the motor cooling portion of the implemented system.

Propulsion Meeting and Project Updates

2012-02-14 - Digitalia Ordered

2012-02-08 - Motor Development Program and Pump Development Program Wiki Updates In Progress

2011-08-05 - Avionics Team Meeting

2003-09-14-propulsion

Scope

The current goal state is a reciprocating cylinder pump that uses high-pressure air and spring returns to cycle the cylinders in our possession. This will be considered a successful test, at which point we will begin to integrate the fuel plumbing. One step at a time.