Pumping fuel with no bubbles is no problem at your local petrol station but up in space it is another matter entirely. Airbus Defence and Space has been helping to advance research in this field – up on the ISS!
The fourth and final series of Capillary Channel Flow (CCF) experiments, the science equipment for which was designed and developed by Space Systems in Friedrichshafen, has just come to an end on the International Space Station.
The goal was to work out how to transport fluids in space reliably and without bubbles, as well as to determine their maximum possible flow speeds.
Space travel is inconceivable without a reliable means of transporting fluids on board spacecraft. This is just as true for space probes and telecoms satellites as it is for future manned missions, and applies equally to water, fuel or fluidised gases. On Earth it is gravity which ensures that petrol sits at the bottom of a car’s fuel tank. But in the microgravity environment of space, the fuel distributes itself throughout the container.
Experts are hoping to come up with new ideas for innovative fuel supply lines, but it is likely that these could also be applied in other space travel contexts, such as life-support systems and thermal systems.
The Capillary Channel Flow experiment was transported to the ISS in April 2010 and originally developed for use during two campaigns, but scientists doubled this to four, accumulating an enormous amount of data during the six months of round-the-clock experiments. The final series of experiments ran successfully on the ISS for nearly six weeks.
Although it will take time to fully evaluate the results, the most important result for practical applications has already been determined – the theoretical model for calculating flow behaviour in capillary channels under microgravity, which researchers had already developed, was confirmed in full by the experiments. This means it is now possible for flow behaviour to be reliably calculated using computer models. In addition, researchers were able to show in tests that air bubbles that already exist in the fluid channel can be automatically removed – even in microgravity – by using specific channel shapes.
The German – US science team responsible for the scientific experiment:
Images -> NASA