In the calculation of Reynold’s Number for the Friction factor of the annulus tube, which is the correct formula for equivalent diameter De?

In the calculation of Reynold’s Number for the Friction factor of the annulus tube, which is the correct formula for equivalent diameter De? Correct Answer \(\frac{4×(D_{oi}^2 – D_{io}^2)×\frac{π}{4}}{π(D_{io}+D_{oi})}\)

While friction factor is calculated for the annulus pipe, the wall friction is provided by both the sides of the tube. Hence when we are calculating the Hydraulic diameter for the annulus, we consider the complete wetted perimeter, that is, P = π(Dio + Doi).
Bissoy MCQ

Related Questions

In the calculation of Reynold’s Number for the Friction factor of the shell, which is the correct formula for equivalent diameter De?
Consider we have a Double Pipe Heat Exchanger, with the inner tube of Outer diameter 20mm (thickness 2mm) and outer tube of inner diameter 30mm. We have two fluids A & B, we desire to have their flow rates as 15 Kg/s and 21 Kg/s respectively. Calculate the convective heat transfer coefficient from tube to annulus side. (Given Nusselt number on tube side = 496 and K = 15W/mK)
In the calculation of Heat Transfer Coefficient on the annulus side for heat transferred to the inner tube, which is the correct formula for equivalent diameter De?
Consider we have a Double Pipe Heat Exchanger, with the inner tube of Outer diameter 20mm (thickness 2mm) and outer tube of inner diameter 30mm. We have two fluids A & B, we desire to have their flow rates as 15Kg/s and 21Kg/s respectively. What is the value of Hydraulic diameter for the annulus tube?
A single pass shell and tube heat exchanger, consisting of a bundle of 100 tubes (inner diameter 25 mm and thickness 2 mm) is used for heating 28 kg/s of water from 25 degree Celsius to 75 degree Celsius with the help of a steam condensing at atmospheric pressure on the shell side with condensing heat transfer coefficient 5000 W/m2 degree. Make calculation for overall heat transfer coefficient based on the inner area. Take fouling factor on the water side to be 0.002 m2 degree/W per tube and neglect effect of fouling factor on the shell side and thermal resistance of the tube wall
For annular flow of a fluid, the ratio of the equivalent diameter for pressure drop calculation to the equivalent diameter for heat transfer calculation is
At low Reynold's number, the power (P) required for agitating a fluid in a stirred tank becomes independent of inertial forces. In this limit, indicate which of the following relations is satisfied:
Po = ρ/ρN3D5: Power number
Re = ρ ND2/μ: Reynold's number
N is the impeller rotational speed and D is the impeller diameter.
The lubricating oil for a large industrial gas turbine engine is cooled in a counter flow, concentric tube heat exchanger. The cooling water flows through the inner tube ( diameter = 25 mm) with inlet temperature 25 degree celsius and mass flow rate 0.2 kg/s. The oil flows through the annulus (diameter = 50 mm) with mass flow rate 0.125 kg/s and its temperature at entry and exit are 90 degree Celsius and 60 degree Celsius. Find outlet temperature of cooling water
If an annulus has an inner diameter of d 1 and an outer diameter of d 2 then the equivalent diameter is
A circular annulus of inner radius r and outer radius R has a uniform charge density a. What will be the total charge on the annulus?