For true centrifugal casting process with the axis of rotation in horizontal direction, an acceleration of $$75g,$$ where $$g$$ is the acceleration due to gravity, is required for sound casting. The relation between diameter. $$'D'$$ (in $$mm$$) and the rotational speed $$N$$ ($$1$$ $$rev/s$$) for this casting is $${N^2}D = $$ constant, determine the constant. Also calculate the mold speed (in $$rev/sec(c)$$ for casting $$CI$$ pipes of $$5m$$ long with outside and inside diameters of $$0.52m$$ and $$0.5m$$ respectively

A cylinder of $$150mm$$ diameter & $$200mm$$ height is to be cast with out any riser. The cylinder is moulded entirely in the drag of a green sand flask & is top gated. The cope of the flask is $$200mm$$ height & the height of the metal during pouring is $$50mm$$ above the cope. A tapered sprue is employed & the gating ratio is $$1:1.5:2$$. The time taken (in seconds) to fill the casting cavity neglecting energy losses, if the in-gate area is $$400sq.mm$$

A casting of $$200\,\,mm\,\, \times \,\,100\,\,mm \times 70\,\,mm$$ size solidifies in ten minutes. Estimate solidification time for a $$200\,\,mm\,\, \times \,\,100\,\,mm \times 10\,\,mm$$ casting under similar conditions?

If the freezing ratio equal to (casting area/casting volume)/(riser area/riser volume) & the volumetric ratio equal to riser volume/casting volume, for a disc casting of $$20cm$$ diameter and $$10$$ $$cm$$ thick are $$1.4$$ and $$0.8$$ respectively. The corresponding values for a square disc of $$20$$ $$cm$$ side and $$10$$ $$cm$$ thick if the same cylindrical riser with a height to diameter ratio of unity is used in both cases.