chris pochari Posted May 29, 2017 Posted May 29, 2017 So I'm interested in learning more about rotor head/hub design so I did some searching and I find that most helicopter books only discuss aerodynamics, this is not really useful for me. I'm looking more specifically for an engineering book that discuss rotor head design. Why is there so little published on helicopter engineering? So far the only book I've found is helicopter design and data manual by Stanley J Dzik which according to the description has a chapter on rotor hub design.My main interest is learning more about swashplateless rotor hubs, Like these below.https://www.google.ch/patents/US20090269199https://dspace-erf.nlr.nl/xmlui/bitstream/handle/20.500.11881/1109/FM08.pdf?sequence=1&isAllowed=y Maybe ichris should write a book 1 Quote
iChris Posted June 2, 2017 Posted June 2, 2017 (edited) So I'm interested in learning more about rotor head/hub design so I did some searching and I find that most helicopter books only discuss aerodynamics, this is not really useful for me. I'm looking more specifically for an engineering book that discuss rotor head design. Why is there so little published on helicopter engineering? My main interest is learning more about swashplateless rotor hubs Most swashplate-less rotor systems, because of the required cyclical nature of control, are implemented via blade trailing edge flaps. The terms you’ll often see, Continuous Trailing Edge Flaps (CTEF) and Warping Actuated Trailing Edge Flaps make clear how the blade flapping is controlled and rotor control accomplished. While most of those swashplate-less technologies offer advantages in rotorcraft performance, the cost of implementation has yet to reach a sufficiently low level to justify their use on production aircraft. Consequently, most of the information you’re looking for is restricted to research papers and technical reports. The NASA Scientific and Technical Information Search engine at: https://ntrs.nasa.gov/search.jsp Try both search types, basic and advanced, using keywords around the subject you’re interested in. It’s also very importation to note the references at the end of each research papers or technical reports. They lead to additional information you can use. The following papers are related to your area of interest: Analysis of a Multi-Flap Control System for a Swashplate less Rotor Continuous Trailing-Edge Flaps for Primary Flight Control of a Helicopter Main Rotor Performance of Swashplateless Ultralight Helicopter Rotor with Trailing-Edge Flaps for Primary Flight Control For the advanced undergraduate and graduate students, engineers, and researchers the following level textbooks cover overall helicopter design: Principles of Helicopter Aerodynamics2nd EditionAuthor: J. Gordon Leishman, University of Maryland, College Park Helicopter Performance, Stability and Controlby Raymond W. Prouty Rotorcraft AeromechanicsAuthor: Wayne Johnson, Aeromechanics Branch of NASA Ames Research Center Edited June 2, 2017 by iChris Quote
chris pochari Posted June 2, 2017 Author Posted June 2, 2017 Most swashplate-less rotor systems, because of the required cyclical nature of control, are implemented via blade trailing edge flaps. The terms you’ll often see, Continuous Trailing Edge Flaps (CTEF) and Warping Actuated Trailing Edge Flaps make clear how the blade flapping is controlled and rotor control accomplished. While most of those swashplate-less technologies offer advantages in rotorcraft performance, the cost of implementation has yet to reach a sufficiently low level to justify their use on production aircraft. Consequently, most of the information you’re looking for is restricted to research papers and technical reports. The NASA Scientific and Technical Information Search engine at: https://ntrs.nasa.gov/search.jsp Try both search types, basic and advanced, using keywords around the subject you’re interested in. It’s also very importation to note the references at the end of each research papers or technical reports. They lead to additional information you can use. The following papers are related to your area of interest: Analysis of a Multi-Flap Control System for a Swashplate less Rotor Continuous Trailing-Edge Flaps for Primary Flight Control of a Helicopter Main Rotor Performance of Swashplateless Ultralight Helicopter Rotor with Trailing-Edge Flaps for Primary Flight Control For the advanced undergraduate and graduate students, engineers, and researchers the following level textbooks cover overall helicopter design: Principles of Helicopter Aerodynamics2nd EditionAuthor: J. Gordon Leishman, University of Maryland, College Park Helicopter Performance, Stability and Controlby Raymond W. Prouty Rotorcraft AeromechanicsAuthor: Wayne Johnson, Aeromechanics Branch of NASA Ames Research CenterThanks a lot, I've found google patent to be useful. What's your opinion on Swashplate-less rotor hubs? The removal of the pitch links and all the hydraulics that go with it seems like an advantage. The need for slip rings seems to be one disadvantage. Quote
iChris Posted June 4, 2017 Posted June 4, 2017 (edited) What's your opinion on Swashplate-less rotor hubs? The removal of the pitch links and all the hydraulics that go with it seems like an advantage. The need for slip rings seems to be one disadvantage. The cost-to-benefit ratio isn’t there yet. While most of those swashplate-less technologies offer advantages in rotorcraft performance, the cost of implementation has yet to reach a sufficiently low level to justify their use on production aircraft. In the design triangle options, we can normally archive any two of the sides; however, archiving all three, a bit more problematic. Active control of helicopter rotor systems has been studied extensively by research organizations in government, industry, and academia for nearly 40 years. The primary goals of these studies have been to reduce rotorcraft noise and vibration, and/or to improve rotorcraft performance, range, and payload. Numerous concepts have been analyzed, studied, and developed to meet these objectives; however, the rotorcraft community has yet to identify a concept that is considered sufficiently successful to be adopted by a major rotorcraft manufacturer for implementation in their aircraft. Evidence exists of some fielded fixed-frame active control devices, but these usually provide significantly reduced control authority as compared to the rotor- system-based active control methods that attack the problems of interest at their source. For active rotor control systems to be adopted in the future, breakthrough technologies will need to be developed that significantly 1) reduce the cost of implementing active rotor control devices, 2) improve active control device reliability and ease of manufacture, and 3) eliminate safety concerns regarding the use of active rotor controls. In short, such a future device will have to “buy its way onto the aircraft” by providing a solution that is less costly to implement than currently fielded technologies while offering a significant improvement in rotorcraft performance through improved range, payload, fuselage vibration reduction, and/or acoustic signature reduction. Edited June 4, 2017 by iChris 1 Quote
chris pochari Posted June 6, 2017 Author Posted June 6, 2017 The cost-to-benefit ratio isn’t there yet. While most of those swashplate-less technologies offer advantages in rotorcraft performance, the cost of implementation has yet to reach a sufficiently low level to justify their use on production aircraft. In the design triangle options, we can normally archive any two of the sides; however, archiving all three, a bit more problematic. Thanks for your work. Always appreciated Quote
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