A finite wing has a torsional stiffness of $12\times 10^{6}$ Nm², a span of 8.0 m, and a mean chord of 2.8 m. If the two-dimensional lift-curve slope is 3.1 and its aerodynamic center is 1.2 m forward of its flexural axis, calculate the wing divergence speed at sea level.

Answer: 269.2 m/s.

Question

A finite wing has a torsional stiffness of $12\times 10^{6}$ Nm², a span of 8.0 m, and a mean chord of 2.8 m. If the two-dimensional lift-curve slope is 3.1 and its aerodynamic center is 1.2 m forward of its flexural axis, calculate the wing divergence speed at sea level.

Answer: 269.2 m/s.

Accepted Answer

From Eq. (29.11),

[latex]V_{d}=\sqrt{\frac{\pi ^{2}GJ}{2 ho ec^{2}s^{2}(\partial c_{1}/\partial \alpha )} } [/latex] (29.11)

[latex]V_{d}=\sqrt{[\pi ^{2} imes 12 imes 10^{6}/2 imes 1.226 imes 1.2 imes 2.8 imes 8^{2} imes 3.1]} [/latex]

i.e.,

[latex]V_{\mathrm{d}}=269.2\,\mathrm{m/s}[/latex]

Question 29.2: A finite wing has a torsional stiffness of 12×10^6 Nm², a sp......

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