Recent content by Baluncore

Since some of the inlet pressures are negative, the pressures must be referenced to atmospheric pressure = 0 bar, with a vacuum = -1.0 bar.

The file attached to post #45, appears to be different to the one you are looking at. It has a different page 16.

That is a 20-page technical document. Please give the page number and identify the figure or table that refers to zero bar.

When the bottom of the object is at 4.0 , the object is 0% submerged and the top of the object is at 5.0 . As you lower the object into the water, the surface of the water covers the object with the water remaining at 5.0 The object goes from 0% submerged, through 50%, to 100% submerged very...

As you lower the object, the bottom meets the water at 4.0 . An instant later, it has displaced one drop of water, that has half filled the narrow space around the piston. The bottom of the object is only just below 4.0, and the water has risen to 4.5 which makes it 50% submerged.

Maybe you should be measuring the submergence relative to the bottom of the object, and the surface of the water, not the top of the object and the bottom of the container. Your last diagram is wrong because you have a tight-fitting piston in a cylinder, the water level should be 5.0.

Neither makes a better, lower pressure, vacuum pump. They both fail, but in different ways. The piston pump needs valves that prevent it pulling a deep vacuum. The external gear pump needs thick oil to seal the gear to case clearance, which makes it inefficient, while the meshed teeth cannot...

Caves and rock shelters on Earth are warmer than being exposed to radiative heat loss to the night sky. The internal thermal gradient of the Earth keeps the rocks warm. The surface rock also averages the night-day temperature distribution on Earth. A hollow asteroid rock shelter could not...

Then why park in orbit with other asteroids when they could be going somewhere. Thrust could give them artificial gravity, while accelerating, then decelerating, towards a more viable destination.

Why do aliens need to simulate gravity by spinning a rock ? Residents, with a vestibular system, could not just look the other way.

Those pumps are expected to be flooded with hydraulic oil, without any air present. I expect those figures are the inlet pressure at which vacuum cavitation, may begin to take place. Cavitation could damage to the internal surfaces.

Welcome to PF. The path of Mars, as seen from Earth, is mapped onto the celestial sphere behind Mars. Maybe it has something to do with the sign of the velocity. When Earth is travelling on the opposite side of the Sun to Mars, the differential velocity has a different sign, to when Earth and...

Referring to the front and back can be confusing because it depends on how you look at it. Maybe refer to the air inlet and outlet, the inlet side of the blade and the outlet side of the blade. Dust accumulates faster on the outlet side of the blade, because, as it pushes the air through the...

"Downwards" suggests that the rod is being accelerated down the y-axis and along the x-axis by gravity. Yes, but only for a finite time. While the force along the rod, due to gravity, is equal to the force applied by the running bug, the rod will remain in equilibrium. The bug will accelerate...

You get your front wheels in the air by accelerating, and hold them there until they pass clear over a step-up, that is then hit by the rear wheels only. The vehicle then rotates forwards about its cross-axis, because the front wheels did not hit the same step-up as the rear wheels.