Orifice Discharging Freely into Atmosphere
Fluid Mechanics · FE Reference Handbook section
Handbook notes for this section
Definitions and conditions exactly as the handbook states them.
- in which h is measured from the liquid surface to the centroid of the orifice opening.
Core formulas for this FE topic
Definitions, applicability, units, assumptions and worked examples for each relation.
Worked exam-style examples
The four ways this section is written on the real exam — thoughts first, then equations, then substitution.
A 35 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 5.1 m. With a discharge coefficient of 0.61, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.0096 m³/s (C_d ignored)
- 0.0587 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 95 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 1.7 m. With a discharge coefficient of 0.60, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.0409 m³/s (C_d ignored)
- 0.1419 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 55 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 7.9 m. With a discharge coefficient of 0.61, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.0296 m³/s (C_d ignored)
- 0.2246 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 90 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 8.0 m. With a discharge coefficient of 0.64, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.0797 m³/s (C_d ignored)
- 0.6391 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 80 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 2.3 m. With a discharge coefficient of 0.61, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.0338 m³/s (C_d ignored)
- 0.1384 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 40 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 7.4 m. With a discharge coefficient of 0.60, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.0151 m³/s (C_d ignored)
- 0.1095 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 50 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 4.2 m. With a discharge coefficient of 0.63, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.0178 m³/s (C_d ignored)
- 0.1019 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 25 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 7.4 m. With a discharge coefficient of 0.62, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.0059 m³/s (C_d ignored)
- 0.0442 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 110.0 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 8.4 m. With a discharge coefficient of 0.63, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.1220 m³/s (C_d ignored)
- 0.9867 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere
A 105.0 mm sharp-edged orifice in the side of a tank discharges freely to the atmosphere under a head of 8.2 m. With a discharge coefficient of 0.64, compute the theoretical velocity, the actual discharge and the jet's volume delivered in one minute.
Given
Find
V_theoretical, Q and the one-minute volume
Start with the thinking
- Torricelli's result comes straight from Bernoulli with atmospheric pressure on both ends.
- The discharge coefficient bundles the vena-contracta area reduction with velocity losses.
Step-by-step solution
Formula
Substituting
Orifice area
Formula
Substituting
Volume in 60 s
Why the other options are there
- 0.1098 m³/s (C_d ignored)
- 0.8916 m³/s (square root omitted)
Reference: FE Reference Handbook — Fluid Mechanics → Orifice Discharging Freely into Atmosphere