## What is the mass balance equation?

A Mass Balance Equation describes the transient distribution of mass at every point in space. This represents the number of mass/moles of ‘i’ that go through a unit area in a unit time. As you might have guessed, it is composed of the diffusive and convective flux terms.

## What are the basic equation of fluid mechanics?

Key Equations

Density of a sample at constant density ρ=mV
Pascal’s principle F1A1=F2A2
Volume flow rate Q=dVdt
Continuity equation (constant density) A1v1=A2v2
Continuity equation (general form) ρ1A1v1=ρ2A2v2

What is mass balance and energy balance?

One of the fundamental laws of physics states that mass can neither be produced nor destroyed—that is, mass is conserved. Equally fundamental is the law of conservation of energy. Although energy can change in form, it can not be created or destroyed.

How do you write energy balance equations?

The complete energy equation looks like this:

1. Energy balance = energy input – energy output.
2. Weight gain = energy input > energy output.
3. Weight loss = energy input < energy output.

### What is U and V in fluid mechanics?

ρ = fluid mass density. u is the flow velocity vector. E = total volume energy density.

### What is Rho in fluid mechanics?

The density of a fluid, designated by the Greek symbol (ρ, rho), is defined as its mass per unit volume. Density is typically used to characterize the mass of a fluid system. In the SI system units of density are kg/m3. Unlike liquids, the density of a gas is strongly influenced by both pressure and temperature.

How does a mass balance work?

In simple terms, a balances measure mass, while scales measure weight. So if you bring a balance and a scale to the moon, the balance will accurately give you the mass of, say, a moon rock, whereas the scale will be affected by the gravity. A balance determines mass by balancing an unknown mass against a known mass.

What is the most basic energy balance equation?

The complete energy equation looks like this:

• Energy balance = energy input – energy output.
• Weight gain = energy input > energy output.
• Weight loss = energy input < energy output.

## What does u stand for in fluid dynamics?

u is the flow velocity vector. E = total volume energy density. U = internal energy per unit mass of fluid.

## What is the mass conservation equation for fluid mechanics?

In fluid dynamics, mass conservation leads to a well-known local continuity equation: \\frac{\\partial\\rho}{\\partial t}+\ abla \\cdot (\\rho {\\bf{u}}) = 0. By integrating this equation over the fluid domain and applying the divergence theorem, we obtain the global formulation of the mass conservation.

What is Bernoulli’s equation in fluid mechanics?

Equations in Fluid Dynamics: Bernoulli’s Equation. $\\frac {P} {\\rho g}$ is the pressure head or pressure energy per unit weight fluid. $\\frac {v^ {2}} {2g}$ is the kinetic head or kinetic energy per unit weight. The Bernoulli equation is different for isothermal as well as adiabatic processes.

What is the use of fluid dynamics in aeroplanes?

Fluid dynamics is used to calculate the forces acting upon the aeroplane. It is used to find the flow rates of material such as petroleum from pipelines. It can also be used in traffic engineering (traffic treated as continuous liquid flow). The Bernoulli equation is different for isothermal as well as adiabatic processes.

### What are the three levels of balance in chemistry?

Mass Balance Momentum Balance Mechanical Energy Balance 2 3 Conserved Quantities Chemical species Mass Momentum