Recovery Factor For Flat Plate With Viscous Flow Calculator

Recovery Factor Formula:

\[ r = \frac{(h_{aw} - h_e)}{(h_0 - h_e)} \]

Adiabatic Wall Enthalpy (h_aw):

J/kg

Static Enthalpy (h_e):

J/kg

Total Specific Enthalpy (h₀):

J/kg

Recovery Factor (r):

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1. What is the Recovery Factor?

The Recovery Factor is a dimensionless number defined by the ratio of difference in enthalpies. It represents the efficiency with which kinetic energy is converted back to thermal energy in viscous flows.

2. How Does the Calculator Work?

The calculator uses the Recovery Factor formula:

\[ r = \frac{(h_{aw} - h_e)}{(h_0 - h_e)} \]

Where:

\( r \) — Recovery Factor (dimensionless)
\( h_{aw} \) — Adiabatic Wall Enthalpy (J/kg)
\( h_e \) — Static Enthalpy (J/kg)
\( h_0 \) — Total Specific Enthalpy (J/kg)

Explanation: The formula calculates the ratio of enthalpy differences to determine how effectively kinetic energy is recovered as thermal energy in viscous flow conditions.

3. Importance of Recovery Factor Calculation

Details: The recovery factor is crucial in aerodynamics and heat transfer analysis, particularly for calculating heat transfer rates in high-speed flows and determining adiabatic wall temperatures in boundary layer flows.

4. Using the Calculator

Tips: Enter all enthalpy values in J/kg. Ensure that all values are positive and that total specific enthalpy is greater than static enthalpy for valid results.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range of recovery factor values?
A: Recovery factor typically ranges between 0.8-1.2 for most fluids, with values close to 1 indicating nearly complete recovery of kinetic energy as thermal energy.

Q2: How does recovery factor relate to Prandtl number?
A: For laminar flow over a flat plate, the recovery factor is approximately equal to the square root of the Prandtl number (r ≈ √Pr).

Q3: Why is recovery factor important in aerospace applications?
A: It's critical for calculating heat transfer to aircraft surfaces at high speeds, where kinetic energy conversion to thermal energy significantly affects surface temperatures.

Q4: Does recovery factor vary with flow regime?
A: Yes, recovery factor values differ between laminar and turbulent flows, with turbulent flows typically having higher recovery factors.

Q5: Can recovery factor be greater than 1?
A: Yes, in some cases recovery factor can exceed 1, particularly in certain turbulent flow conditions or with specific fluid properties.