- Introduction to LTA
- Recent Developments
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A new book, Principles of Aerostatics, is now available, and will be reviewed in the September issue of Airship. The book presents the complete theory of static lift for airships, aerostats and balloons. Concepts are laid out, and building on the derivation of temperature, pressure, density and humidity in the atmosphere and the gas laws, formulas for static lift are derived. The variation of lift with atmospheric and airship parameters, climb and descent, and flight above pressure height are then explored. Both SI and United States Customary Units are employed throughout, and worked examples and calculator programs are provided. That may sound daunting, but the mathematical process can be followed by a reader with an understanding of high school algebra.
A summary of the attached paper is published in the June edition of AIRSHIP, No. 184. As the paper is approximately 100 pages long, we have elected to provide a complete copy for download from here, with a shortened summary reproduced in the journal.
Therefore, this paper is designed to be accessible to members in receipt of the June edition of AIRSHIP only. Anyone may download it, but you will require a password to access the file. The password can be found on page 23 of AIRSHIP No. 184.
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Re-fuelling and re-supply of LTAV and Airships while under-way is an important tool to extend the endurance and range of LTAV. The United States Navy (USN) developed and practiced various procedures to enable re-fuelling and re-supply at sea, starting with the Airship Tender USS Patoka in the 1920's, and developing those procedures until the end of the USN use of Airships in the early 1960's.
Results of the first phase of a rigid airship "D-20" creation for cargo transportation with lifting capacity up to 20 tons are considered. An airship feature is the opportunity of cargo transportation both on an outside load and inside of a vehicle hull.
The stratospheric platform airship as the communication infrastructure shall have an enough station keeping capability at a high altitude during a long term. This airship requires a very lightweight electric power system which can be operated continuously for a long term. In this case the combined system of the photovoltaics and the regenerative fuel cell is the most promising system as an onboard power plant. The development of a lightweight and highly reliable regenerative fuel cell is the most critical item for this advanced power plant.
High Altitude Platforms (HAPs) are airships or planes that will be located in the stratosphere at heights of approximately 17 - 22 km. They are gaining considerable attention at the moment as a delivery vehicle forbroadband communications and other services. The European HeliNet programme is one such project, now in its third year of study. We present a summary of results and a suggested architecture for the delivery of a cellular broadband network, the design of which is constrained by the mass and power available for the proposed Heliplat payload.
This paper presents the current status of the development of an autonomous blimp. Details are given on the hardware setup, which is currently almost operational. A flight decomposition allowing to define canonical navigation phases from takeoff to landing is proposed. For each phase a reduced model is determined and a controller is designed on the base of back-stepping techniques. This approach allows to consider the kinematic and dynamic requirement separately.
A thoroughly verified statistical model of learning with degenerative feedback is used to evaluate results of airship flight testing – the probability of mission success and its confidence limit. The main communication zest is as follows: testing with corrective action is considered as the process of a continuous vehicle’s perfection until all specification requirements are met and confirmed. The result can be used as a part of evidence for airship airworthiness certification.
In 1997, the airship research group FOGL was established at the University of Stuttgart, Germany. Among others, the remotely controlled airship Lotte was chosen as reference configuration to perform scientific investigations in the fields of aerodynamics, flight mechanics and control, aeroelasticity, structural design and solar propulsion systems. The present paper addresses theoretical and experimental aerodynamic studies on the Lotte configuration. An overview on the wind- and water-tunnel tests performed so far and a summarized description of the theoretical models developed is given.