What do you mean by free convection?
What do you mean by free convection?
Natural convection, known also as free convection is a mechanism, or type of mass and heat transport, in which the fluid motion is generated only by density differences in the fluid occurring due to temperature gradients, not by any external source (like a pump, fan, suction device, etc.).
What is the definition of convection flow?
Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy).
What is difference between free and forced convection?
In free convection, the molecules move due to density and temperature variation. In forced convection, the fluid molecules are forced to move by an external source. The rate of heat transfer is lower. The rate of heat transfer is higher.
What is the example of free convection?
One of the most common examples of natural convection is the phenomena of the sea and land breeze. Sea breeze: This phenomenon occurs during the day. The sun heats up both the sea surface and land.
What causes free convection?
The driving force for natural convection is gravity. For example if there is a layer of cold dense air on top of hotter less dense air, gravity pulls more strongly on the denser layer on top, so it falls while the hotter less dense air rises to take its place. This creates circulating flow: convection.
What is the reason for free convection?
Free convection is fluid motion due to buoyancy forces. Free convection, also referred to simply as convection, is driven by the static instability that results when relatively dense fluid lies above relatively light fluid.
What is convection definition and example?
Convection is the transfer of heat by circulating it through air or liquids. A heat source at the bottom of the balloon heats the air molecules around the flame, and those molecules rise. Warmer air is less dense than cold air, so as the warm air rises the molecules spread out.
What is convection and examples?
Everyday Examples of Convection This hot water rises and cooler water moves down to replace it, causing a circular motion. radiator – A radiator puts warm air out at the top and draws in cooler air at the bottom. ice melting – Ice melts because heat moves to the ice from the air.
What are two types of convection?
There are two types of convection: natural convection and forced convection.
Is free convection turbulent?
Free-convective flows may be laminar and turbulent. A flow past a solid surface, the temperature of which is higher (lower) than that of the surrounding flowing medium, is the most widespread type of free convection.
What is the difference between free convection and heat transfer?
• Free convection refers to fluid motion induced by buoyancy forces. • Buoyancy forces may arise in a fluid for which there are density gradients and a body force that is proportional to density. • In heat transfer, density gradients are due to temperature gradients and the body force is gravitational.
What is free free convection?
Free convection, or natural convection, is a spontaneous flow arising from nonhomogeneous fields of volumetric (mass) forces (gravitational, centrifugal, Coriolis, electromagnetic, etc.):
What is convection and how does it work?
Convection is the process of heat transfer in fluids by the actual motion of matter. It happens in liquids and gases. It may be natural or forced. It involves a bulk transfer of portions of the fluid. How is Heat Transferred through Convection? When a fluid is heated from below, thermal expansion takes place.
What is free convection Chapter 9?
Free Convection: Chapter 9 Free Convection 2 General Considerations • Free convection refers to fluid motion induced by buoyancy forces. • Buoyancy forces may arise in a fluid for which there are density gradients and a body force that is proportional to density.