Discussion: “Loss and Stall Analysis of Compressor Cascades” (Lieblein, Seymour, 1959, ASME J. Basic Eng., 81, pp. 387–397)

Abstract

surface diffusion ratio (value above which {6/0)2 becomes excessive), blades should be designed for low friction coefficient (high Reynolds number and low relative surface roughness) and minimum laminar flow (high Reynolds number and high free-stream turbulence). The experimental correlation between wake momentum thickness and suction-surface diffusion ratio was made applicable for conventional blade-design use by empirically establishing an equivalent diffusion ratio expressible in terms of only the design velocity triangle and the blade solidity. The possibility of blade stall at minimum loss and greater angles of attack, as evidenced by a sharp rise in wake momentum thickness, occurred when the equivalent diffusion ratio attained a value of about 2. With the use of the equivalent diffusion ratio, calculations were made of the total-pressure loss and unstalled range of operation of conventional cascade sections as functions of solidity, air inlet angle, and air turning angle.

Ultrastructure of Granular Cell Change in a Wilm's Tumor

“…In these tumors, heterologous elements such as smooth muscle, striated muscle, adipose tissue, cartilage, bone and neural elements have been reported. 1,4,5 The granular cells in our case show the sub-structural characteristics of Schwann cells (basal lamina which is sometimes duplicated, broad-banded collagen, long cytoplasmic extensions, cytoplasmic lysosomes) but do not show the immunohistochemical staining pattern for Schwann cells (positive CD 57, and S100) as is seen in the majority of adult granular cell tumors. 6 Our case shows the typical findings seen ultrastructurally and immunohistochemically for granular cell tumors but does not support a Schwann cell origin.…”