Wall confinement effects for spheres in the Reynolds number range of 30-2000

T h i s t h e s i s s t u d i e s i n d e t a i l : formation, developmen and i n s t a b i l i t y o f the v o r t e x r i n g ; a s s o c i a t e d s u r f a c e p r e s s u r e d i s t r i b u t i o n ; and drag f o r a f a m i l y of spheres i n the Reynolds number range of 30-2000 and the blockage r a t i o of 3-30%. In the beginning, a g l y c e r o l w a t e r s o l u t i o n t u n n e l used i n the experimental program i s b r i e f l y d e s c r i b e d f o l l o w e d by an e x p l a n a t i o n o f the model support system, p r e s s u r e measuring i n s t r u m e n t a t i o n , drag balance and t e s t procedures. An approach to the data r e d u c t i o n , so c r i t i c a l a t low Reynolds number, i s d i s c u s s e d and a new d e f i n i t i o n of the pressure c o e f f i c i e n t which promises to be l e s s dependent on t e s t f a c i l i t i e s and p r e s s u r e g r a d i e n t s i s e v olved. F i n a l l y , the t e s t data are analyzed as f u n c t i o n s of the confinement c o n d i t i o n and Reynolds number. The r e s u l t s suggest t h a t the r a t i o of the model to v e r t i c a l stem support should be a t l e a s t 10 to make stem e f f e c t s n e g l i g i b l e . I n f l u e n c e o f Reynolds number on the s u r f a c e p r e s s u r e d i s t r i b u t i o n i s p r i m a r i l y c o n f i n e d to the range R < 1000. However, f o r the model wi t h the • n h i g h e s t blockage r a t i o of 30.6%, the p r e s s u r e continues to show Reynolds number dependency f o r R n as high as 2300 ( l i m i t o f the tunnel c a p a b i l i t y f o r a g l y c e r o l w a t e r