Disks free fall

Fig. 6.7 Regimes of motion for disks in free fall or rise. Contours of constant Strouhal number Sr and constant Reynolds number are also shown.

No data are available for heat and mass transfer to or from disks or spheroids in free fall. When there is no secondary motion the correlations given above should apply to oblate spheroids and disks. For larger Re where secondary motion occurs, the equations given below for particles of arbitrary shape in free fall are recommended. 

Figure 2.10 Cylindrically symmetric hydrodynamical model of accretion flow with rotation during the early collapse phase, showing the inflow of matter in the meridional plane and the build-up of a flat rotating disk structure after about 1.05 free-fall times. Arrows indicate matter flow direction and velocity, gray lines indicate cuts of isodensity surfaces with meridional plane. Dark crosses outline locations of supersonic to subsonic transition of inflow velocity this corresponds to the position of the accretion shock. Matter falling along the polar axis and within the equatorial plane arrive within 1600 yr almost simultaneously, which results in an almost instantaneous formation of an extended initial accretion disk [new model calculation following the methods in Tscharnuter (1987), figure kindly contributed by W. M. Tscharnuter],...

Sohds in either phase are sedimented to the underside of the disks and shde outward along the surfaces because of their density. The aggregated sohds must move by free settling from the outer edges of the disks to the bowl wall some may be reentrained into new feed material, and carried into the disk stack, which accounts in part for actual performance falling short of theoretical prediction. 

While chylomicrons in lymph contain apoA-I as a major apolipoprotein, plasma chylomicrons do not normally contain apoA-I, and apoA-I appears to transfer from chylomicrons to HDL in plasma (A23, P4, S8, T5). Parks and Rudel compared the kinetic fates of labeled apoA-I and apoA-II from lymph chylomicrons in monkeys (P4). The two apolipoproteins behaved differently when injected into plasma. ApoA-II appeared to be almost instantaneously transferred from injected chylomicrons into HDL, while the tracer apoA-I specific activity rose in HDL for 1-3 hours after chylomicron injection, before falling at a rate identical to that of autologous HDL apoA-I tracer. These and other findings suggest that some chylomicron apoA-I transferred to chylomicron remnants or to disks or vesicles of redundant surface material released from chylomicrons, or remained free in solution, rather than immediately transferring to HDL. 

---