Mass flow, also known as “mass transfer” and “bulk flow”, is the movement of fluids down a pressure or temperature gradient , particularly in the life sciences. ... Examples of mass flow include blood circulation and transport of water in vascular plant tissues.
What is mass flow in a plant?
Mass flow is the movement of dissolved nutrients into a plant as the plant absorbs water for transpiration. ... Thus, a high concentration in the soil solution and a low concentration at the root cause the nutrients to move to the root surface, where they can be taken up.
What is mass flow in physics?
In physics and engineering, mass flow rate is the mass of a substance which passes per unit of time . Its unit is kilogram per second in SI units, and slug per second or pound per second in US customary units. The common symbol is. (ṁ, pronounced “m-dot”), although sometimes μ (Greek lowercase mu) is used.
What is fuel mass flow?
The fuel mass flow rate is related to the total engine air flow rate mdot a by the fuel to air ratio f . The energy equation for the burner can be solved for the temperature ratio across the burner: Tt4 / Tt3 = (1 + f * nb * Q / (cp * Tt3)) / (1 + f)
What is mass flow in humans?
Mass flow systems work together with the specialised exchange systems (such as lungs). ... In humans the right side of the heart pumps blood to the lungs only and is called the pulmonary circulation , while the left side of the heart pumps blood to the rest of the body – the systemic circulation.
Why is mass flow rate important?
Direct mass flow measurement is an important development across industry as it eliminates inaccuracies caused by the physical properties of the fluid, not least being the difference between mass flow and volumetric flow. Mass is not affected by changing temperature and pressure.
What is the difference between mass flow rate and volume flow rate?
“Volumetric flow rate is a measure of the 3-dimensional space that the gas occupies as it flows through the instrument under the measured pressure and temperature conditions. ... Mass flow rate is a measure of the number of molecules that flow through the instrument, regardless of how much space those molecules occupy.
How does mass flow occur?
The mass flow hypothesis is a theory which attempts to explain how solutes are transported from source cells into sinks through the phloem . ... The removal of solutes increases the water potential at the sink end, causing water to move out of the phloem by osmosis.
How does mass flow work?
How does a mass flow meter work? Mass flow meters operate either by introducing a known amount of heat into the flowing stream and measuring an associated temperature change or by maintaining a probe at a constant temperature and measuring the energy required to do so.
How do you calculate mass flow?
We can determine the value of the mass flow rate from the flow conditions. A units check gives area x length/time x time = area x length = volume. The mass m contained in this volume is simply density r times the volume. To determine the mass flow rate mdot, we divide the mass by the time.
What controls the fuel flow?
Gas turbine engines are primarily controlled by the amount of fuel supplied to the combustion chambers. With this in mind we can say that, the very simplest fuel control for a turbine engine is a fuel valve operated by the pilot.
What is a good air/fuel ratio?
It used to be that 12.5:1 was considered the best power ratio, but with improved combustion chambers and hotter ignition systems, the ideal now is around 12.8:1 to 13.2:1 . This is roughly 13 parts of air to one part fuel.
How do I calculate flow rate?
Flow rate is the volume of fluid per unit time flowing past a point through the area A. Here the shaded cylinder of fluid flows past point P in a uniform pipe in time t. The volume of the cylinder is Ad and the average velocity is ̄ ̄ ̄v=d/t v ̄ = d / t so that the flow rate is Q=Ad/t=A ̄ ̄ ̄v Q = Ad / t = A v ̄ .
What is bulk flow in blood?
Bulk flow is a process used by small lipid-insoluble proteins to cross the capillary wall . ... When moving from the interstitium to the blood, bulk flow is termed re-absorption. The kidney is a major site of bulk flow where waste products are filtered from the blood.
Is bulk flow passive or active?
Like the active transport processes that move ions and small molecules via carrier proteins, bulk transport is an energy-requiring (and, in fact, energy-intensive) process.
What is bulk mass flow?
Mass flow or bulk flow is the movement down a pressure gradient ( a pressure gradient in plants is observed due to variations in solute concentration) or temperature gradient of substances in bulk or in masses. Xylem and phloem in plants play a similar role as veins and arteries in animals.
