Hydraulics

density of water in kg/m³

1000 kg/m³

specific gravity of mercury

13.6

1 horsepower is equal to how many watts

746

total hydrostatic pressure on plane area (plane surface)

Location of force P on the plane surface

eccentricity

Total hydrostatic pressure on a curved surface

Horizontal component of total hydrostatic pressure on a curved surface

Vertical component of total hydrostatic pressure on a curved surface

formula for buoyant force from Archimedes’ Principle

Distance from metacenter to the center of buoyancy for rectangular sections (MB_o)

Distance from metacenter to the center of buoyancy for other sections (EXACT)

Distance from metacenter to the center of buoyancy for other sections (APPROXIMATE)

Factor of safety against overturning in DAMS

Factor of safety against sliding in DAMS

Location of R_y (x bar) in DAMS

e in DAMS

foundation pressure when e <= B/6 (DAMS; min and max)

foundation pressure when e > B/6 (DAMS; min and max)

qmin is 0

Walls carrying stress in pipes and tanks (thickness of wall)

where S_t is the actual or allowable tensile stress in the wall

Walls carrying stress in pipes and tanks (center-to-center spacing of the hoops)

where T is the tensile force in one hoop (N)

angle theta for a horizontally moving vessel

angle theta for a vessel moving on an inclined plane

use plus when upward and minus when downward

pressure p when the vessel is moving vertically

use plus when upward and minus when downward

angle theta for rotating vessels

distance y for rotating vessels

velocity head

total head or energy (meters)

slope of the energy grade line

Power

power computed using this formula is in watts

In pumps, the first power solved is an?

Output

In turbines, the first power solved is an?

Input

formula for efficiency

general Darcy-Weisbach Formula (hint: uses f)

Darcy-Weisbach formula for circular pipes

MaNNing formula

Hazen-Williams formula (for circular pipes)

minor loss (given k_m)

Relationship of the flow rates of pipes in series

Q₁ = Q₂ = Q₃

Relationship of the head losses of pipes in series

total head loss is h_f1 + h_f2 + h_f3

Relationship of the flow rates of pipes in parallel

total flow rate is Q₁ + Q₂ + Q₃

Relationship of the head losses of pipes in Parallel

h_f1 = h_f2 = h_f3

celerity for RIGID pipes (water hammer)

celerity for NON-RIGID pipes (water hammer)

composite modulus of elasticity

time required for the pressure wave to travel from the valve to the reservoir and back to the valve (hint: time limit for water hammer)

water hammer pressure for rapid closure

water hammer pressure for slow closure

Reynold’s Number

altenate formula substituting nu: magtanim ay dvrho

kinematic viscosity, nu

friction factor when flow is laminar

friction factor when flow is turbulent

type of flow where its flow rate is the same along its length

Continuous flow (think equation of continuity)

type of flow where its flow rate does not vary over time

steady flow

type of flow where its flow rate varies over time

unsteady flow

type of flow where its velocity does not vary over its length

uniform flow

type of flow where its velocity varies over time

non-uniform flow

type of flow where its specific energy is at its minimum

critical flo

mababaw tapos mabilis

supercritical flow

malalim tas mabagal

subcritical flow

theoretical velocity used for orifices

Toricelli’s Formula

actual velocity used for orifices

coefficient of discharge

C

Head loss when orifices are involved

specific gravity of air

0.0012

Impact of a jet on a plane/ Force on the Jet (at a right angle)

Force on Pipe’s Bend and Reducer, also used for curved vanes/blades

Q for a rectangular-shaped weir (neglecting velocity of approach)

Francis formula for rectangular-shaped weirs (neglecting velocity of approach)

WEIRS: for contracted sections, replace L with L’. What is L’ for singly contracted sections?

WEIRS: for contracted sections, replace L with L’. What is L’ for doubly contracted sections?

Q for triangular shaped weirs

or use 1.4H^5/2 when theta is 90^o

Cipolletti Weir

4V : 1H

orifice tapos constant width

orifice tapos varying width

C by Bazin

C by Kutter

most efficient circular pipe for max Q

d=0.94D

most efficient circular pipe for max v

d=0.81D

most efficient trapezoidal section

width at the top = sum of the sides

Froude number for rectangular sections

equation to get critical depth