Table of Contents
What exactly is moment of inertia?
moment of inertia, in physics, quantitative measure of the rotational inertia of a body—i.e., the opposition that the body exhibits to having its speed of rotation about an axis altered by the application of a torque (turning force).
What does moment of inertia depend on?
The moment of inertia depends not only on the object’s mass, but also the distribution of that mass in relation to the axis of rotation. When an ice skater in a spin pulls their arms in, their mass stays the same, but their moment of inertia decreases.
Is moment the same as inertia?
Inertia is the property of matter which resists change in its state of motion. Unlike inertia, moment of inertia depends not only on the mass but also the distribution of mass around the axis about which the moment of inertia is to be calculated. An object can have different moments of inertia about different axes.
What is PCD in turbine?
Compressor discharge pressure (PCD) is a key factor in gas turbine performance. Beta’s MAO service determines the deviation in PCD from a baseline relationship with gas producer speed, N1. In the case shown here, PCD looks unremarkable, but the deviation in PCD tends to be jump between -7\% and -3\%.
What is inertia in simple terms?
1 : a property of matter by which it remains at rest or in motion in the same straight line unless acted upon by some external force. 2 : a tendency not to move or change He stayed at the job mostly because of his inertia.
Why is the moment of inertia important?
The MOI of an object determines how much torque an object needs to reach a specific angular acceleration. When calculating torque, or rotational force, you need to know the mass MOI.
What is NPT in gas turbine?
NGp = gas producer speed, NGG gas generator speed) NPt (power turbine speed in a 2 shaft machine) and then other things like driven equipment speed.
What is NGP and NPT?
NGP – Gas turbine speed. NPT – Power turbine speed.
What does a small moment of inertia mean?
Higher moments of inertia indicate that more force has to be applied in order to cause a rotation whereas lower moments of inertia means that only low forces are necessary. When the body has an increased radius, i.e. during the initial and final phase of a dive, moment of inertia is large and angular velocity is small.
What is moment of inertia in physics?
Theory The moment of inertia, I, is a measure of the way the mass is distributed on the object and determines its resistance to angular acceleration. Every rigid object has a de nite moment of inertia about a particular axis of rotation.
What is the inertia constant of a generator turbine unit?
The Inertia constant (H) of a generator-turbine unit is defined as the ratio of kinetic energy stored at the synchronous speed (ωsynm) to the generator kVA or MVA rating (SB). The inertia constant of the current GB system was estimated using the low frequency incident that occurred on 27 May 2008.
Can we measure the inertia of the electricity system in real time?
Last week saw the news that National Grid has successfully trialled a method of measuring the inertia of the electricity system in real time. This may seem like a technical curiosity, but it has major implications for system management. Electrical inertia is the property of the system which opposes changes in current.
How does a machine contribute to the inertia of a system?
In order for a machine to contribute to system inertia, there has to be a direct electromagnetic coupling between the machine and the power system which allows disturbances on the system to be translated into a mechanical torque that acts on the machine rotor.