Liquid Flow 11

1. Liquid Flow Clothing
2. Liquid Flow Sensor

Liquid Flow

Pumpman Solar Water Pump Range is ideal for animal feed water, household water and light irrigation. This range is ideal to pump up to 90m head. It has a 3-year warranty. If you want to pump more than this look at our High Head range. Our six years of experience and intensive local.Find Out More. The flow of gas has many similarities to the flow of liquid, but it also has some important differences. First, gas is compressible, whereas liquids are generally considered to be incompressible.

The Lohm has been selected so that a 1 Lohm restriction will permit a flow of 100 gallons per minute of water with a pressure drop of 25 psi at a temperature of 80°F.

Some useful relationships:

Liquid Flow – Examples

Problem 1. What restriction will permit a flow of 1 gallon of water per hour at 50 psi ΔP?

Problem 2. An orifice with a hole diameter of .012' flows 18 lb/hr of water at 100 psi ΔP.
How many Lohms?

Problem 3. What ΔP will be required to flow 20 GPH of water through a 2000 Lohm orifice?

Problem 4. What water flow will result from a restriction of 500 Lohms and a ΔP of 500 psi?

NOTE: For special flow requirements, The Lee Company can determine the required Lohm rating.

Liquid Flow – Two Forumlas for Combinations of Restrictors

PARALLEL FLOW, the total Lohm rating is:

Please note that this relationship is identical to the electrical equation. Money pro 2 4 torrent.

SERIES FLOW, the total Lohm rating is:

Please note that this relationship is not the same as in electrical problems. The difference is due to the non-linearity of

Please note that this relationship is not the same as in electrical problems. The difference is due to the non-linearity of

For passageway size: DT = D/ N1/4

D_T = Diameter of a single equivalent orifice, with a Lohm rate = L_T Colibri 1 9 9.

D = Diameter of the actual orifices, each with a Lohm rate = L₁

Liquid Flow - Series Flow

One of the reasons for using two restrictors in series is to allow fine tuning of a total resistance value. If L₁ is known and is more than 90% of L_T, then L₂ may vary by ±5% without altering the value of L_T by more than ±1%, even though the value of L₂ may be as high as 40% of L_T . This effect becomes even more pronounced as L₁ approaches L_T.

To determine the intermediate pressure between two resistances in series, the following formulas may be used.

Liquid Flow - Flow Formula

The following formulas are presented to extend the use of the Lohm laws to many different liquids, operating over a wide range of pressure conditions.

NOMENCLATURE

Liquid Flow

The following formulas are presented to extend the use of the Lohm laws to many different liquids, operating over a wide range of pressure conditions.

These formulas introduce compensation factors for liquid density and viscosity. They are applicable to any liquid of known properties, with minimum restrictions on pressure levels or temperature.

The units constant (K) eliminates the need to convert pressure and flow parameters to special units.

Liquid Flow

The following formulas are presented to extend the use of the Lohm laws to many different liquids, operating over a wide range of pressure conditions.

These formulas introduce compensation factors for liquid density and viscosity. They are applicable to any liquid of known properties, with minimum restrictions on pressure levels or temperature.

The units constant (K) eliminates the need to convert pressure and flow parameters to special units.

Volumetric Flow Units

Gravimetric Flow Units

Liquid Flow - Units Constant K

Volumetric Flow Units

Gravimetric Flow Units

Liquid Flow Calculations – Examples

Problem 1. An orifice is required to flow 0.15 GPM of MIL-H-83282 hydraulic fluid at 80°F and 100 psi ΔP. What restriction is required?

Solution:

1. Read specific gravity; S = 0.84 from chart here.
2. Read viscosity; v = 21_cs. From chart here.
3. Use viscosity and ΔP to determine viscosity compensation factor V = 0.95 from graph here.
4. Select units constant, K = 20 from table here.
   

Problem 2. What pressure drop will result from a flow of 5 PPH of SAE #10 lubricating oil at 20°F, flowing through a 1000 Lohm orifice?

Solution:

1. Read specific gravity and viscosity.
   S = 0.90, v = 600_cs.
2. Use knowledge of system to assume solution.
   H = 50 psid.
3. Use assumed ΔP to determine V = 0.18
4. Select units constant, K = 10,000 from table here.
5. Compute trial ΔP.
   
6. Make trials as required to find correct solution.
   H = 26 psid.

Problem 3. A Safety Screen is required to flow 775 lb/hr of diesel fuel @ 80°F with a maximum pressure drop of 5 psid.
What is the maximum Lohm rate allowed for the Safety Screen?

Solution:

1. Find specific gravity; S = 0.87 from curve here.
2. Find viscosity; v = 3.1_cs from curve here.
3. Use v and ΔP to determine viscosity compensation factor, V = 0.87 from curve here.
4. Select units constant, K = 10,000 from table here.
   

Viscosity Compensation Factor For Single Orifice

Flow regimes in gas-liquid flows

When a gas and a liquid are forced to flow together inside a pipe, there are at least 7 different geometrical configurations, or flow regimes, that are observed to occur. The regime depends on the fluid properties, the size of the conduit and the flow rates of each of the phases. The flow regime can also depend on the configuration of the inlet; the flow regime may take some distance to develop and it can change with distance as (perhaps) the pressure, which affects the gas density, changes. For fixed fluid properties and conduit, the flow rates are the independent variables that when adjusted will often lead to changes in the flow regime.

Here are three regimes for air-water flow in a 1.27 cm in pipe.

Liquid Flow Clothing

These videos are from 'Two Phase Flow Regimes in Reduced Gravity', NASA Lewis Research Center Motion Picture Directory 1704.

By J. B. McQuillen, R. Vernon and A. E. Dukler.

The video was taken at 400 fps and the projection is at 29.97 fps.

Superficial gas velocity = .16 m/s, Superficial liquid velocity = .90 m/s.

In this example of bubbly flow, the liquid flow rate is high enough to break up the gas into bubbles, but it is not high enough to cause the bubbles to become mixed well within the liquid phase. If the pipe were oriented vertically, the phase orientation would be symmetric, but there would likely be 'slip' between the phases and the gas would not move at the same speed as the liquid.

Superficial gas velocity = 7.4 m/s, Superficial liquid velocity = .08 m/s.

In annular flow, the liquid coats the walls. However, because of gravity, the liquid distribution is not symmetric with much more liquid on the bottom of the pipe than the top. The velocity of the gas is large enough to cause waves to form in the liquid and also to atomize some liquid. The maximum possible wave amplitudes scale, for liquid layers that are not too thin, as roughly the liquid thickness.

Liquid Flow Sensor

Superficial gas velocity = .17 m/s, Superficial liquid velocity = .08 m/s.

The slug regime, is characterized by the presence of liquid rich slugs that span the entire channel or pipe diameter. These travel at a speed that is a substantial fraction of the gas velocity and occur intermittently. They cause large pressure and liquid flow rate fluctuations. The movie shows the approach of one slug. It looks like a large flow surge, or a large wave. Other movies of slugs would show much more gas entrainment or that the liquid slug clearly touches the top of the pipe. The length to diameter ratio of slugs varies greatly with flow rates, pipe diameter and fluid properties. If the diameter is very large, the Froude number, g d/U^2 can always be large and slug flow, where the entire diameter is bridged, will not form. Instead roll waves, which are breaking traveling waves, will be seen. Liquid may or may not coat the entire pipe because there will be substantial atomization.

Here are the same flow rates if gravity is reduced to an insignificant level.

Superficial gas velocity = .13 m/s, Superficial liquid velocity = .89 m/s.

In this example of bubbly flow, there is no gravity so that there is no buoyancy force on the gas bubbles. Thus they mix freely within the liquid.

Akvis artwork 11 0. Superficial gas velocity = 8.1 m/s, Superficial liquid velocity = .08 m/s.

Now that gravity is removed, the liquid distribution is uniform around the pipe. Large disturbance waves still occur but they are seen as 'ring - like' disturbances. The absence of gravity also increases the amplitude to film depth ratio of traveling waves because there is no liquid drainage from the wave caused by gravity.

Superficial gas velocity = .16 m/s, Superficial liquid velocity = .08 m/s.

In the absence of gravity, the liquid distribution is uniform and the slugs are now liquid 'trapped' between traveling 'Taylor Bubbles'. This flow will not experience large pressure fluctuations and the flow rate fluctuations occur only on the size of the bubbles. This is close to the idealized slug regime that is considered in the calculations below.

The calculations in the notebook given below show directly that for the easily calculable case of laminar flow, the flow regime greatly influences the pressure - drop flow rate relation. Thus, if design or operation of a device requires accurate knowledge of flow rate and pressure drop, there is a need to know the flow regime. The rates of heat and mass transfer are also often important in process equipment and the movies suggest that these will also depend significantly on the flow regime!

In the mathematica notebook, Effect of flow regime on pressure drop, we will see that the geometric configuration of the phases can greatly affect the pressure drop. Also, consider how heat transfer to the pipe would be affected if the pipe were being heated by flames.