Method for predicting pump cavitation performance

Method requires the availability of two sets of appropriate data for each pump to be analyzed. At least one set of the data must provide measurable thermodynamic effects of cavitation

Experimental studies on thermodynamic effects of developed cavitation

A method for predicting thermodynamic effects of cavitation (changes in cavity pressure relative to stream vapor pressure) is presented. The prediction method accounts for changes in liquid, liquid temperature, flow velocity, and body scale. Both theoretical and experimental studies used in formulating the method are discussed. The prediction method provided good agreement between predicted and experimental results for geometrically scaled venturis handling four different liquids of widely diverse physical properties. Use of the method requires geometric similarity of the body and cavitated region and a known reference cavity-pressure depression at one operating condition

Performance with and without inlet radial distortion of a transonic fan stage designed for reduced loading in the tip region

A transonic compressor stage designed for a reduced loading in the tip region of the rotor blades was tested with and without inlet radial distortion. The rotor was 50 cm in diameter and designed for an operating tip speed of 420 m/sec. Although the rotor blade loading in the tip region was reduced to provide additional operating range, analysis of the data indicates that the flow around the damper appears to be critical and limited the stable operating range of this stage. For all levels of tip and hub radial distortion, there was a large reduction in the rotor stall margin

Energy as Frequency, Relative Velocity and Lorentz Transformations

In quantum mechanics, energy is associated with frequency for both a particle with rest mass and a photon. In the case of the photon, we try to show that this result follows from special relativity (Lorentz transformation) which in the photon case gives rise to relative velocities. We consider a photon moving along the x axis and bouncing back and forth between two mirrors separated by L and moving to the right with speed v. We argue that Lorentz transformations for photons create the notion of relative velocity because E=|p|c, but there still exists a moving frame with velocity v. As a result, a relationship between the energies of the photon moving to the right and then to the left exists with each energy being multiplied by a respective time= 1/ relative speed. This suggests photon energy representing a frequency. . We also note that relative velocities from the Lorentz transformations are the opposite of those associated with the times the photon spends moving from one mirror to the other.. In other words, the photon moving to the right is associated with 1/c-v, but its time with 1/c-v because it looks as if the photon is moving more slowly when trying to hit a mirror that is moving away from it

Forgetfulness of continuous Markovian quantum channels

The notion of forgetfulness, used in discrete quantum memory channels, is slightly weakened in order to be applied to the case of continuous channels. This is done in the context of quantum memory channels with Markovian noise. As a case study, we apply the notion of weak-forgetfulness to a bosonic memory channel with additive noise. A suitable encoding and decoding unitary transformation allows us to unravel the effects of the memory, hence the channel capacities can be computed using known results from the memoryless setting.Comment: 6 pages, 2 figures, comments are welcome. Minor corrections and acknoledgment adde