192

G. Shailaja and N. Chari

Table 14.2 Wingbeat frequency calculations using Norberg formulae

S. No.

Name of the flier

Mass (M) (kg)

Formula

Freqency (Hz) Est

I

Birds

0.020

3.87 M^−0.33

–

Sparrow

Parrot

0.022

3.98 M^−0.27

–

Pigeon

0.250

8.5

Shore bird

0.400

4.00 M^−0.19

–

0.500

–

Duck

1.000

5.00 M^−0.24

–

H swift

0.0186

3.87 M^−0.33

11

0.0112

to

H swift

0.0186

3.98 M^−0.27

–

0.0112

13

Humming bird

0.020

1.32 M^−0.60

–

0.015

–

0.0112

–

II

Bats

0.0075

3.98 M^−0.27

4.6

H speoris

Leaf nosed bat

0.250

4

0.400

to

0.500

8

Rousettus

0.0070

3.87 M^−0.27

7–9

III

Insects

0.020

3.87 M^−0.33

Grass Hopper

15–20

0.025

T. Javanica

0.000857

50~

Honey Bee

0.0080

250~

Crysocoris purpurieus

0.0090

90~

Bambus

0.00017

130~

He proposed the formula

f ∝(mg)^αb^β S^γ I ^δρ^ε

(14.1)

I, the moment of inertia depends on body mass and wing span I ∝mb².

Thus equation is converted into practical predictive equation for frequency as

f = 1.08 ×



m

3

8 g

1

2 b

−23

24 s

−1

3 ρ

−3

8