Chapter 2 Pressure distribution in a fluid (Fluid Statics Basic) White Chapter 2 潘錦珈:第一章
1 White: Chapter 2 潘锦珊： 第一章 Chapter 2 Pressure Distribution in a fluid (Fluid Statics Basic)
Pressure △F Definition: p=lim 0△A Unit Pa=N/m2(sl) kg/cm" atm mmHg mmHo PSI ( Pound per Squire Inch) Properties of Pressure u Vertical to the surface and point into it O At any point, pressure is independent of orientation
2 A F p A = → lim 0 Definition: Unit: 2 Pa = N m (SI) 2 kg cm atm PSI mmHg mmH2 O (Pound per Squire Inch) ❑ Vertical to the surface and point into it. ❑ At any point, pressure is independent of orientation. Properties of Pressure Pressure
Verification: At any point in a static fluid, pressure is independent of orientation (up) Forces on left and up surface G=Pg(-bAxAz) P=p,b△y △ P=p,b sin e △ Px=pn bAy=p,bsin 0 sin e p2=pn+pg△ When)0→P1=p2=pn=p
3 At any point in a static fluid, pressure is independent of orientation. Verification: = + = p p g z p p z n x n 2 1 When z ⎯→0 px = pz = pn = p pn y x z x pz x p ) 2 1 G = g( bxz (up) sin sin y p b y p b x n = sin y P p b n n = P p b y x = x Forces on left and up surface: x :
Fluid mechanics Fluid Dynamics Fluid statics Fluid in motion Fluid at rest Aerodynamics
4 Fluid Mechanics Fluid at rest Aerodynamics Fluid Statics Fluid Dynamics Fluid in motion
§21 Fluid@rest u Pressure is the only surface force O Pressure distribution relates to body force only Applications 口Dams(水坝) 口 Buoyancy related instrument(利用浮力的装置) 口 Fluid power system(液压驱动系统 口 Connected vessel(连通器)
5 ❑ Pressure is the only surface force. ❑ Pressure distribution relates to body force only. ❑ Dams（水坝） ❑ Buoyancy related instrument（利用浮力的装置） ❑ Fluid power system（液压驱动系统） ❑ Connected vessel （连通器） ❑ …… Applications: § 2.1 Fluid @ rest