Free falling and wind tunnel experiments of model spherical fireworks shells have been carried out, in order to examine the effect of air resistance to the exterior ballistics of the shells. It was found that at the initial stage of free falling the air resistance is negligible and the result of ballistic calculation is practically not affected by using different drag coefficients. The drag coefficients of empty shells were estimated by free falling and wind tunnel experiments at a Re region.
煙火玉の外部弾道に対する空気抵抗の効果を検討するために，球形模擬玉の自由落下実験と風洞実験を行った。自由落下の初期段階では，空気抵抗は無視でき，弾道計算の結果は異なる抵抗係数を用いても実質的には影響を受けないことがわかった。空玉の抵抗係数を自由落下及び風洞実験からあるレイノールズ数の領域で推定した。
Fireworks, Model shell, Free falling, Wind tunnel, Air resistance