What is a reaction energy diagram?
An energy diagram can be defined as a diagram showing the relative potential energies of reactants, transition states, and products as a reaction progresses with time. The activation energy is the difference in the energy between the transition state and the reactants.
What is energy curve?
In chemical bonding: The quantum mechanics of bonding. …used to construct a molecular potential energy curve, a graph that shows how the energy of the molecule varies as bond lengths and bond angles are changed.
What is the bond distance that gives the minimum energy?
The internuclear distance at which the potential energy minimum occurs defines the bond length. This is more correctly known as the equilibrium bond length, because thermal motion causes the two atoms to vibrate about this distance. In general, the stronger the bond, the smaller will be the bond length.
Which line represents the total energy?
The total (mechanical) energy of this system is conserved (i.e. it is the same for every position of the object), which explains why the total energy graph is a horizontal line.
What is total energy grade line?
Definition: Total Energy Line or Energy Grade Line i.e. TEL is defined as a line joining the points representing the total head. It means the total energy line represents the sum of (P/γ + V²/2g + Z). For ideal or non-viscous fluid there are no losses hence TEL for that fluid is a horizontal line.
What is HGL?
The surface or profile of water flowing in an open channel or a pipe flowing partially full. If a pipe is under pressure, the hydraulic grade line is that level water would rise to in a small, vertical tube connected to the pipe.
How do you calculate HGL?
HGL is determined by subtracting the velocity head (V2/2g) from the energy gradient (or energy grade line). Figure 1 illustrates the energy and hydraulic grade lines for open channel and pressure flow in pipes.
What is the difference between HGL and EGL?
A hydraulic grade line (HGL) can be drawn to show the variation of the piezometric head. An energy grade line (EGL) shows the variation of the total head. Since the difference between the total head and the piezometric head is the velocity head, the distance between the EGL and the HGL is also the velocity head.
What is datum head?
Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum. It is usually measured as a liquid surface elevation, expressed in units of length, at the entrance (or bottom) of a piezometer.
What is head in a pipe?
Head is the height at which a pump can raise water up, that’s it, it’s that simple. Connect a tube to the discharge of a pump and measure the water height, that the head of the pump.
How do you calculate head loss?
The calculation for working out the pressure loss within an installation is as follows:
- Head Loss (Pc) = [Equiv. pipe length + Installation pipe length] x Pc % / 100 x Corrector.
- Equivalent pipe length.
- Installation pipe length.
- Pc % and Corrector.
What is the head of the pump?
So, what is pumping head or just “head?” Head is the maximum height that a pump can move fluid against gravity. The purest example of this is if you have a vertical pipe extending straight up from the discharge outlet. A pump with 5m of head will pump fluid up the pipe 5m from the discharge outlet.
What is total dynamic head of a pump?
Total Dynamic Head (TDH) is the amount of head or pressure on the suction side of the pump (also called static lift), plus the total of 1) height that a fluid is to be pumped plus 2) friction loss caused by internal pipe roughness or corrosion.
What is static and dynamic head of a pump?
In fluid dynamics, Total Dynamic Head (TDH) is the total equivalent height that a fluid is to be pumped, taking into account friction losses in the pipe. TDH = Static Height + Static Lift + Friction Loss. where: Static Height is the maximum height reached by the pipe after the pump (also known as the ‘discharge head’).
What causes dynamic head loss?
“A long-in-service pump’s dynamic head can vary from the published curve.” Pressure demands in pumped liquid systems come from dynamic and static sources. Friction in the system causes the dynamic losses. For Newtonian fluids, these losses are proportional to the square of the velocity in the system.
What is delivery head of pump?
Expressed more simply, the delivery head is equal to the pressure measured at the discharge port minus the inlet pressure applied at the suction port. The delivery head is generally specified in m. Generally speaking, the delivery head is represented together with the flow rate in the form of the QH curve.