# What is div grad?

## What is div grad?

Another way of composing vector derivatives is to take div(gradf) for a scalar function f. It is easy to check that for f:Rn→R of class C2, div(gradf)=n∑j=1∂jjf=: the Laplacian of f.

## Is grad and div same?

it is the derivative of f in each direction. The gradient of a scalar field is a vector field. An alternative notation is to use the del or nabla operator, Ñf = grad f. div F is a scalar field it can also be written as Ñ.

**What do div curl and grad refer to?**

Curl describes the rotation of the flow described by the vector field, i.e. the tendency for a point particle in the field to rotate about some point. Finally, grad or gradient describes how a given scalar function is changing in each direction.

**What is Div curl F?**

If we again think of →F as the velocity field of a flowing fluid then div→F div F → represents the net rate of change of the mass of the fluid flowing from the point (x,y,z) ( x , y , z ) per unit volume. This can also be thought of as the tendency of a fluid to diverge from a point.

### What are the properties of Grad, Div and curl?

We introduce three ﬁeld operators which reveal interesting collective ﬁeld properties, viz. the gradient of a scalar ﬁeld, the divergence of a vector ﬁeld, and the curl of a vector ﬁeld. There are two points to get over about each: The mechanics of taking the grad, div or curl, for which you will need to brush up your multivariate calculus.

### What are Grad, Div and curl in vector operators?

Lecture 5 Vector Operators: Grad, Div and Curl In the ﬁrst lecture of the second part of this course we move more to consider properties of ﬁelds. We introduce three ﬁeld operators which reveal interesting collective ﬁeld properties, viz. the gradient of a scalar ﬁeld, the divergence of a vector ﬁeld, and the curl of a vector ﬁeld.

**What does the divergence of div F mean?**

A positive divergence is indicating a flow away from the point. Physically divergence means that either the fluid is expanding or that fluid is being supplied by a source external to the field. The lines of flow diverge from a source and converge to a sink. If there is no gain or loss of fluid anywhere then div F= 0.

**What is the divergence of a vector field F?**

Consider a vector field F that represents a fluid velocity: The divergence of F at a point in a fluid is a measure of the rate at which the fluid is flowing away from or towards that point. A positive divergence is indicating a flow away from the point.