Velocity At Maximum Endurance Given Preliminary Endurance For Prop-Driven Aircraft Calculator

Formula Used:

\[ V(E_{max}) = \frac{(LD_{E_{max}ratio} \times \eta \times \ln(\frac{W_{L(beg)}}{W_{L,end}}))}{(c \times E)} \]

Lift to Drag Ratio at Maximum Endurance:

(dimensionless)

Propeller Efficiency:

(dimensionless)

Weight of Aircraft at Beginning of Loiter Phase:

Weight of Aircraft at End of Loiter Phase:

Power Specific Fuel Consumption:

kg/s/W

Endurance of Aircraft:

seconds

Velocity for Maximum Endurance:

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1. What is Velocity at Maximum Endurance?

Velocity at Maximum Endurance is the velocity at which a prop-driven aircraft can loiter for maximum time, achieving the highest possible endurance during flight operations.

2. How Does the Calculator Work?

The calculator uses the following formula:

\[ V(E_{max}) = \frac{(LD_{E_{max}ratio} \times \eta \times \ln(\frac{W_{L(beg)}}{W_{L,end}}))}{(c \times E)} \]

Where:

\( LD_{E_{max}ratio \) — Lift to Drag Ratio at Maximum Endurance (dimensionless)
\( \eta \) — Propeller Efficiency (dimensionless)
\( W_{L(beg)} \) — Weight of Aircraft at Beginning of Loiter Phase (kg)
\( W_{L,end} \) — Weight of Aircraft at End of Loiter Phase (kg)
\( c \) — Power Specific Fuel Consumption (kg/s/W)
\( E \) — Endurance of Aircraft (seconds)

Explanation: This formula calculates the optimal velocity for maximum endurance by considering the aircraft's aerodynamic efficiency, propulsion efficiency, weight changes during loiter, and fuel consumption characteristics.

3. Importance of Velocity at Maximum Endurance

Details: Determining the optimal velocity for maximum endurance is crucial for mission planning, fuel efficiency optimization, and extending the operational range of prop-driven aircraft during surveillance, reconnaissance, or other loiter-based missions.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Ensure weight values are positive and propeller efficiency is between 0 and 1. All values must be valid and greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why is velocity at maximum endurance important for aircraft operations?
A: It allows aircraft to remain airborne for the maximum possible time, which is critical for missions requiring extended loiter capabilities such as surveillance, search and rescue, or environmental monitoring.

Q2: How does propeller efficiency affect the velocity calculation?
A: Higher propeller efficiency increases the overall propulsion effectiveness, allowing the aircraft to achieve better endurance performance at optimal velocities.

Q3: What factors influence the lift to drag ratio at maximum endurance?
A: Aircraft design, wing configuration, and flight conditions all contribute to the lift to drag ratio, which directly affects the optimal velocity for maximum endurance.

Q4: How does weight change during loiter affect the calculation?
A: As fuel is consumed during loiter, aircraft weight decreases. This weight reduction affects the optimal velocity for maintaining maximum endurance throughout the mission.

Q5: Are there limitations to this calculation method?
A: This calculation assumes steady-state flight conditions and may need adjustments for atmospheric variations, aircraft configuration changes, or non-standard flight profiles.