APLIKASI BERNOULLI PADA Saluran Kovergen/Divergen Diffuser, Sudden expansion Fluida gas Flowmeter : Pitot tube, Orificemeter, Venturimeter, Rotameter

PERS.BERNOULLI Steady

PERS.BERNOULLI HEAD FORM OF BERNOULLI EQUATION

DIFFUSER Cara untuk untuk memperlambat kecepatan aliran V1,P1,A1 2 1 z1-z2 V1,P1,A1 V2,P2,A2

SUDDEN EXPANSIONS Cara untuk untuk memperlambat kecepatan aliran 1 2 P1,V1 P2,V2=0 z1-z2

BERNOULLI UNTUK GAS Patmosfir -------------------- ------------- 1 VR,PR P1,V1 -------------------- P1-Patm V (ft/s) Psia (Eq.5.17) -------------------------- 0.001 35 0.1 111 0.3 191 0.6 267 1.0 340 2.0 467 5.0 679 ------------- V(ft/s) (Eq.in Chap.8) --------- 35 111 191 269 344 477 714 (Eq.5.17) Eq.in Chap.8

BERNOULLI FOR FLUID FLOW MEASUREMENT 1 2 h1 h2 • • PITOT TUBE

VENTURIMETER 1 2 V2,P2 V1,P1 Manometer

Venturi Flowmeter The classical Venturi tube (also known as the Herschel Venturi tube) is used to determine flowrate through a pipe.  Differential pressure is the pressure difference between the pressure measured at D and at d D d Flow

ORIFICEMETER 1 2 Orifice plate Circular drilled hole              where,   Co - Orifice coefficient         - Ratio of CS areas of upstream to that of down stream                                 Pa-Pb  - Pressure gradient across the orifice meter      - Density of fluid

ORIFICEMETER              where,   Co - Orifice coefficient         - Ratio of CS areas of upstream to that of down stream                                 Pa-Pb  - Pressure gradient across the orifice meter      - Density of fluid

incompressible flow through an orifice

compressible flow through an orifice Y is 1.0 for incompressible fluids and it can be calculated for compressible gases.[2] For values of β less than 0.25, β4 approaches 0 and the last bracketed term in the above equation approaches 1. Thus, for the large majority of orifice plate installations: Y = Expansion factor, dimensionless r = P2 / P1 k = specific heat ratio (cp / cv), dimensionless

compressible flow through an orifice

compressible flow through an orifice k = specific heat ratio (cp / cv), dimensionless = mass flow rate at any section, kg/s C = orifice flow coefficient, dimensionless A2 = cross-sectional area of the orifice hole, m² ρ1 = upstream real gas density, kg/m³ P1 = upstream gas pressure, Pa   with dimensions of kg/(m·s²) P2 = downstream pressure in the orifice hole, Pa  with dimensions of kg/(m·s²) M = the gas molecular mass, kg/kmol    (also known as the molecular weight) R = the Universal Gas Law Constant = 8.3145 J/(mol·K) T1 = absolute upstream gas temperature, K Z = the gas compressibility factor at P1 and T1, dimensionless

Sudden Contraction (Orifice Flowmeter) Orifice flowmeters are used to determine a liquid or gas flowrate by measuring the differential pressure P1-P2 across the orifice plate P1 P2 d D Flow 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 102 105 106 107 Re Cd 103 104 Reynolds number based on orifice diameter Red

ROTAMETER Tansparent tapered tube with diameter D0+Bz Solid ball with diameter D0 Density B 3 2 2 1 z=0 Fluid with density F

ROTAMETER D0+Bz Solid ball D0 Density B 3 2 2 1 F z=0 Only one possible value that keep the ball steaduly suspended

ROTAMETER D0+Bz For any rate the ball must move to that elevation in the tapered tube where Solid ball D0 Density B 3 2 2 1 F z=0 The height z at which the ball stands, is linearly proportional to the volumetric flowrate Q

TEKANAN ABSOLUT NEGATIF ? 2 40ft 1 10ft Applying the equation between point 1 and 3 3 Applying the equation between point 1 and 2 ? negatif This flow is physically impossible. It is unreal Because the siphone can never lift water more than 34 ft (10.4 m) above the water surface It will not flow at all