Q2. What is the effect of Reynolds number on the shedding frequency of the clouds?
The 531 effect of Reynolds number is primarily linked to the shedding frequency of the cavitation structures; 532 indeed, when considering a constant cavitation number σ, at low back pressures (which also 533 corresponds to low Reynolds number) the shedding frequency is lower.
Q3. What is the effect of the Reynolds number on the frequency of the cavitation shedding?
The increase of the Reynolds 550 number with the corresponding increase of the velocity increases the rate of generation of vortices and 551 consequently the frequency of shedding of the resulting cavitating structures.
Q4. What was the effect of the 77 studies on the erosion development?
The 77 studies were conducted in a cavitating Venturi nozzle section, where part of the nozzle was covered 78 by a thin aluminium foil; this enabled the rapid accumulation of erosion pits and allowed the 79 observation of the erosion development, since the rest nozzle walls were transparent.
Q5. What is the effect of the increase of the Reynolds number on the collapse frequency?
It seems that the increase of the 31 Reynolds number leads to a reduction of the collapse frequency; it is believed that this effect is due to 32 the agglomeration of vortex cavities, which causes a decrease of the apparent frequency.
Q6. Why has the majority of experimental research focused on methods with which cavitation damage could be linked?
Due to the aforementioned detrimental 51 effects of cavitation on hydraulic equipment, most of experimental research has focused over the 52 years on methods with which cavitation damage could be quantified and linked to measurable 53material properties.
Q7. Why is vortex shedding inferred from the simulations?
Due to the complexity of the flow 22 field, direct observation of the flow structures was not possible, however vortex shedding is inferred 23 from relevant simulations performed for the same conditions.
Q8. What is the notable example of a DNS 90 study of the collective bubble collapse?
One notable example of a DNS 90 study of the collective bubble collapse is the recent work of[20], where the authors employed massive 91 parallelism to simulate a cluster of 15,000 bubbles collapsing near a wall, utilizing a grid with size of 92 13 trillion cells.
Q9. How many e disturbances are there at the outlet of the disks gap?
In each plot, the feed inlet area corresponds to the circle in oncentrically with it, a thin zone has been plottedreflections have prevented the collectionsymmetric at the outlet of the disks gap; there are four outlet e a disturbance in the velocityposition of ~25mm.
Q10. What is the axisymmetric geometry used for the cavitation cloud?
The cavitation cloud was found to change location rather transiently and non-axisymmetrically 196 despite the steady-state operation and the axisymmetric geometry utilized; a typical sequence of the 197 cloud formation and development is shown in Fig.
Q11. What is the contribution of the pressure wave propagation within the 642 bubbly medium?
The contribution of the pressure wave propagation within the 642 bubbly medium is possibly a driving factor on the development of discrete cavitation clouds, but in 643 the present cannot be taken into account, due to limitations of the modelling capabilities of the 644 software used.