Conceptual Design Optimization of High-Altitude Airship Having a Tri-Lobed Envelope

Author(s):  
M. Manikandan ◽  
Rajkumar S. Pant
2011 ◽  
Vol 133 (12) ◽  
Author(s):  
I. T. Watson ◽  
B. Gangadhara Prusty ◽  
J. Olsen ◽  
D. Farrell

The Thompson coupling is a relatively recent design of constant-velocity coupling, that is, principally based on the double Cardan mechanism. An extra mechanism comprising a spherical pantograph serves to align the intermediate shaft of this coupling and so maintains the constant velocity of the double Cardan mechanism, in a modular fashion. This technical note serves to introduce basic closed form expressions for the coupling’s geometry—which may then be used to derive linkage accelerations and dynamic forces. The expressions are derived using standard identities in spherical geometry. The resulting dynamic model then informs a basic conceptual design optimization, which object is intended to reduce induced driveline vibrations, when the coupling is articulated at nonzero angles of torque transmission.


2015 ◽  
Vol 52 (4) ◽  
pp. 1021-1037 ◽  
Author(s):  
Robert E. Thompson ◽  
John M. Colombi ◽  
Jonathan Black ◽  
Bradley J. Ayres

Author(s):  
Xiao-bo Zhang ◽  
Zhan-xue Wang ◽  
Li Zhou ◽  
Zeng-wen Liu

AbstractIn order to obtain better integrated performance of aero-engine during the conceptual design stage, multiple disciplines such as aerodynamics, structure, weight, and aircraft mission are required. Unfortunately, the couplings between these disciplines make it difficult to model or solve by conventional method. MDO (Multidisciplinary Design Optimization) methodology which can well deal with couplings of disciplines is considered to solve this coupled problem. Approximation method, optimization method, coordination method, and modeling method for MDO framework are deeply analyzed. For obtaining the more efficient MDO framework, an improved CSSO (Concurrent Subspace Optimization) strategy which is based on DOE (Design Of Experiment) and RSM (Response Surface Model) methods is proposed in this paper; and an improved DE (Differential Evolution) algorithm is recommended to solve the system-level and discipline-level optimization problems in MDO framework. The improved CSSO strategy and DE algorithm are evaluated by utilizing the numerical test problem. The result shows that the efficiency of improved methods proposed by this paper is significantly increased. The coupled problem of VCE (Variable Cycle Engine) conceptual design is solved by utilizing improved CSSO strategy, and the design parameter given by improved CSSO strategy is better than the original one. The integrated performance of VCE is significantly improved.


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