Feasibility of Modern Airships: Preliminary Assessment

Performance of non-rigid airships operating in the neutral buoyancy condition

“…A parameter dependent on position of transition B buoyancy, N C DS drag coefficient of body or airship based on S C DSH Hoerner's estimate of C DS (hull/body only) C DV drag coefficient of body or airship based on V 2/3 C DVH Hoerner's estimate of C DV (hull/body only) C f skin friction coefficient c p propeller power coefficient, P/(ρn 3 It was also decided that this study should be limited to conventionallyshaped hulls: streamline bodies of revolution with hull fineness ratios in the range 3 < L/d < 10, where L is the length of the body and d is its maximum diameter. The geometric relations assumed for airship hulls (often referred to as envelopes) are presented in Appendix A.…”

“…Some general trends for airship drag are derived. The mass breakdown of non-rigid airships with hull volumes up to 35,000m 3 is analysed using parametric equations. The maximum feasible airspeed and useful load carrying capacity of projected airships are calculated.…”

Very Large Stationary Aerial Platforms

“…15,16,17,18 At an altitude of 70,000 feet the winds are generally very light, averaging 10 knots, and are of variable direction. This altitude is referred to as the "crossover" altitude.…”

“…There has been considerable research on the subject of high altitude superpressure-powered aerostats (HASPA). 15,16,17,18 At an altitude of 70,000 feet the winds are generally very light, averaging 10 knots, and are of variable direction. This altitude is referred to as the "crossover" altitude.15 Also, an airship operating at this altitude should have a minimum station-keeping capability of 30 knots.17 Therefore, an altitude of 70,000 feet was choosen for further analysis.…”

Investigation of Aerodynamic Parameters of a Hybrid Airship

“…H YBRID airships have been acknowledged as a potential means of alternative transportation, and many have come up with promising conceptual designs [1][2][3][4]. Hybrid airships have been the subject of research, especially those that can carry huge payloads and those that can operate at high altitudes.…”