Predict the Flow Direction of Hot Fluid Flowing Through a Non-transparent Pipe Under Certain Constraints?2 min read
Consider a non-transparent pipe through which hot fluid is flowing. Predict the direction of flow under certain constraints.
Constraints
- The pipe is non-transparent. So, flow can not be visualized across pipe.
- The length of the pipe is infinite. So, flow direction can not be identified from either end.
- Flow measuring devices are not installed.
- The surrounding temperature can be assumed around 25 0C.
Simple Observation
Flow direction can be predicted by making a simple observation.
- Fluid temperature is more than the surrounding temperature. There will be a transfer of heat from hot fluid to the surrounding along the length of pipe.
- Touch the pipe at two different locations which are far from each other.
- Feel the change in temperature of pipe at both locations.
- Based on the above observation, fluid is flowing from left to right.
Critical Thinking
Always there is an energy dissipation in the direction of the flow. Moreover, there is a temperature gradient between hot fluid and surroundings. So, when the hot fluid moves along the pipe, it will lose its energy at a faster rate. As a result, there will be a drop in the temperature along the direction of flow.