scholarly journals Tools and methodologies for box-wing aircraft conceptual aerodynamic design and aeromechanic analysis

2021 ◽  
Vol 22 ◽  
pp. 39
Author(s):  
Karim Abu Salem ◽  
Palaia Giuseppe ◽  
Cipolla Vittorio ◽  
Binante Vincenzo ◽  
Zanetti Davide ◽  
...  
Keyword(s):  
Design Process ◽  
Statistical Data ◽  
Aerodynamic Design ◽  
High Lift ◽  
Induced Drag ◽  
Design Variables ◽  
Loading Ratio ◽  
Feasible Space ◽  
Lifting System ◽  
Control Surfaces

A way to face the challenge of moving towards a new greener aviation is to exploit disruptive aircraft architectures; one of the most promising concept is the PrandtlPlane, a box-wing aircraft based on the Prandtl's studies on multiplane lifting systems. A box-wing designed accordingly the Prandtl “best wing system” minimizes the induced drag for given lift and span, and thus it has the potential to reduce fuel consumption and noxious emissions. For disruptive aerodynamic concepts, physic-based aerodynamic design is needed from the very early stages of the design process, because of the lack of available statistical data; this paper describes two different in-house developed aerodynamic design tools for the PrandtlPlane conceptual aerodynamic design: AEROSTATE, for the design of the box-wing lifting system in cruise condition, and THeLMA, aiming to define the layout of control surfaces and high lift devices. These two tools have been extensively used to explore the feasible space for the aerodynamic design of the box-wing architecture, aiming to define preliminary correlations between performance and design variables, and guidelines to properly initialize the design process. As a result, relevant correlations have been identified between the rear-front wing loading ratio and the performance in cruise condition, and for the rear-front flap deflections and the aeromechanic characteristics in low speed condition.

On the Coupling of Designer Experience and Modularity in the Aerothermal Design of Turbomachinery

2008 ◽  
Author(s):  
Jerome P. Jarrett ◽  
Tiziano Ghisu ◽  
Geoffrey T. Parks
Keyword(s):  
Exchange Rates ◽  
System Design ◽  
Design Process ◽  
System Performance ◽  
Preliminary Design ◽  
Aerodynamic Design ◽  
Potential Cost ◽  
Final Performance ◽  
Design Variables ◽  
Rules Of Thumb

The turbomachinery aerodynamic design process is characterized both by its complexity and the reliance on designer experience for success. Complexity has led to the design being decomposed into modules; the specification of their interfaces is a key outcome of preliminary design and locks-in much of the final performance of the machine. Yet preliminary design is often heavily influenced by previous experience. While modularity makes the design tractable, it complicates the appropriate specification of the module interfaces to maximize whole-system performance: coupling of modularity and designer experience may reduce performance. This paper sets out to examine how such a deficit might occur and to quantify its cost in terms of efficiency. Two disincentives for challenging decomposition decisions are discussed. The first is where tried-and-tested engineering “rules of thumb” accord between modules: the rational engineer will find alluring a situation where each module can be specified in a way that maximizes its efficiency in isolation. The second is where there is discontinuity in modeling fidelity, and hence difficulty in accurately assessing performance exchange rates, between modules. In order to both quantify and reduce the potential cost of this coupling we have recast the design problem in such a way that what were previously module interface constraints become key system design variables. An example application of our method to the design of a generic turbofan core compression system is introduced. It is shown that nearly 1 percentage point equivalent compressor adiabatic efficiency can be saved.

On the Coupling of Designer Experience and Modularity in the Aerothermal Design of Turbomachinery

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Jerome P. Jarrett ◽  
Tiziano Ghisu ◽  
Geoffrey T. Parks
Keyword(s):  
Exchange Rates ◽  
System Design ◽  
Design Process ◽  
System Performance ◽  
Preliminary Design ◽  
Aerodynamic Design ◽  
Potential Cost ◽  
Final Performance ◽  
Design Variables ◽  
Rules Of Thumb

The turbomachinery aerodynamic design process is characterized both by its complexity and the reliance on designer experience for success. Complexity has led to the design being decomposed into modules; the specification of their interfaces is a key outcome of preliminary design and locks-in much of the final performance of the machine. Yet preliminary design is often heavily influenced by previous experience. While modularity makes the design tractable, it complicates the appropriate specification of the module interfaces to maximize whole-system performance: coupling of modularity and designer experience may reduce performance. This paper sets out to examine how such a deficit might occur and to quantify its cost in terms of efficiency. Two disincentives for challenging decomposition decisions are discussed. The first is where tried-and-tested engineering “rules of thumb” accord between modules: the rational engineer will find alluring a situation where each module can be specified in a way that maximizes its efficiency in isolation. The second is where there is discontinuity in modeling fidelity, and hence difficulty in accurately assessing performance exchange rates between modules. In order to both quantify and reduce the potential cost of this coupling, we have recast the design problem in such a way that what were previously module interface constraints become key system design variables. An example application of our method to the design of a generic turbofan core compression system is introduced. It is shown that nearly one percentage point of the equivalent compressor adiabatic efficiency can be saved.

Performance Distribution Analysis and Robust Design

2000 ◽  
Vol 123 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Jianmin Zhu ◽  
Kwun-Lon Ting
Keyword(s):  
Robust Design ◽  
Robust Parameter Design ◽  
Distribution Analysis ◽  
Performance Space ◽  
Sensitivity Distribution ◽  
Performance Sensitivity ◽  
Design Variables ◽  
Robust Parameter ◽  
Performance Distribution ◽  
Feasible Space

The paper presents the theory of performance sensitivity distribution and a novel robust parameter design technique. In the theory, a Jacobian matrix describes the effect of the component tolerance to the system performance, and the performance distribution is characterized in the variation space by a set of eigenvalues and eigenvectors. Thus, the feasible performance space is depicted as an ellipsoid. The size, shape, and orientation of the ellipsoid describe the quantity as well as quality of the feasible space and, therefore, the performance sensitivity distribution against the tolerance variation. The robustness of a design is evaluated by comparing the fitness between the ellipsoid feasible space and the tolerance space, which is a block, through a set of quantitative and qualitative indexes. The robust design can then be determined. The design approach is demonstrated in a mechanism design problem. Because of the generality of the analysis theory, the method can be used in any design situation as long as the relationship between the performance and design variables can be expressed analytically.

Aerodynamics Performances of Tunnel Jet Fan and its Passage Components Design

2013 ◽  
Vol 325-326 ◽  
pp. 310-314 ◽  
Author(s):  
Di Lin Pan ◽  
Kai Chen
Keyword(s):  
Design Process ◽  
Flow Resistance ◽  
Rational Design ◽  
Static Pressure ◽  
Internal Flow ◽  
Aerodynamic Design ◽  
Road Tunnels ◽  
Jet Fan ◽  
Ventilation Systems

Jet fans are widely used in ventilation systems of road tunnels, railway tunnels and subways etc. It was demonstrated that the static pressure generated by jet fan impeller is merely useful for overcoming its own internal flow resistance and can not improve the ventilation state of tunnel. It was pointed out that in the aerodynamic design process, the static pressure of jet fan should be made as small as possible. The effective way to reduce static pressure produced by impeller is the rational design of jet fan passage components.

A Decomposition Method for Concurrent Design of Mixed Discrete/Continuous Systems

1993 ◽  
Author(s):  
Jeffrey M. Ford ◽  
Christina L. Bloebaum
Keyword(s):  
Design Process ◽  
Decomposition Method ◽  
Organizational Design ◽  
Method Development ◽  
Minimum Weight ◽  
Optimization Methods ◽  
Continuous Systems ◽  
Computationally Efficient ◽  
Subspace Optimization ◽  
Design Variables

Abstract Interest in Concurrent Engineering (CE) has increased as industry looks for more efficient means of product design. Design optimization methods that facilitate the CE approach are an important aspect of current research. Among the methods that have been proposed is the Concurrent Subspace Optimization (CSSO) method, which allows the optimization problem to be decomposed into coupled subproblems. These subproblems may correspond to the different disciplines involved in the design process or to participating organizational design or manufacturing groups. The decomposition allows each discipline to apply their own optimization criteria to the problem. While this method may not be as computationally efficient as other methods, it allows the design process to conform to the departmental divisions that already exist in industry. The method development to date has focused on continuous systems only. However, problems that can not be modeled as continuous systems, such as those involving the placement of active controllers in CSI applications, would benefit from a method that allows the use of discrete parameters. The paper presents a decomposition method (based on CSSO) for the optimal design of mixed discrete/continuous systems. The method is applied to the design of a composite plate for minimum weight, with design variables contributed from sizing variables (continuous) and material combinations (discrete).

Building an Expert System for Engineering Design Based on the Object-Oriented Knowledge Representation Concept

1988 ◽  
Author(s):  
S. Akagi ◽  
K. Fujita
Keyword(s):  
Expert System ◽  
Knowledge Representation ◽  
Engineering Design ◽  
Design Process ◽  
Model Building ◽  
Object Oriented ◽  
Design Model ◽  
Design Problems ◽  
Design Variables ◽  
Effective Diagnosis

Abstract An expert system is developed for engineering design based on object-oriented knowledge representation concept. The design process is understood as determining design variables and their relationships which compose design model. The design model is represented as a network in the computer system using the object-oriented knowledge representation. The system built with the above concept provides the following abilities: 1) flexible model building and easy modification, 2) effective diagnosis of the design process, 3) supporting method for redesign, 4) a hybrid function with numerical computations and graphics, and 5) applicability for various design problems. Finally, it is applied to the basic design of a ship.

Optimal shape design of a brake calliper for squeal noise reduction considering system instability

2010 ◽  
Vol 224 (7) ◽  
pp. 909-925 ◽  
Author(s):  
H J Soh ◽  
J-H Yoo
Keyword(s):  
Topology Optimization ◽  
Design Process ◽  
Optimization Design ◽  
Parametric Design ◽  
Unstable Mode ◽  
Complex Eigenvalue ◽  
Noise Generation ◽  
Design Variables ◽  
Asymmetric Shape ◽  
Squeal Noise

Squeal is a noise phenomenon occurring in the last stage of automobile braking with a high-frequency sound. It is very difficult to express the phenomenon using a mathematical model, since the origin of squeal noise is physically complex. However, the possibility of squeal generation can be predicted by solving the vibration equation of the self-excited system using the complex eigenvalue analysis method. The results of the method are expressed as the magnitude of the unstable mode, and the generation of squeal noise can be prevented by reducing the magnitude of the unstable mode of the brake system. The objective of this research is to determine the optimal design process focused on the calliper housing shape to suppress squeal noise generation by reducing the system instability. The objective function is set to minimize the real part of the complex eigenvalue, i.e. the instability index. In the optimization design process, the design variable for topology optimization is established by focusing on the finger part of the calliper housing, which transmits the braking pressure to the pad lining. To supplement the complex shape generated by the topology optimization process, parametric design variables are selected for the subsequent process. Parameters are set to adjust the housing finger stiffness and are defined by considering the topology optimization result. Finally, the asymmetric shape of the calliper housing is obtained to reduce squeal noise generation.

Behavior-Form Double Directions Creative Conceptual Design Model and Its Quotient Space Implementation

2008 ◽  
Author(s):  
Yu-Xin Wang ◽  
Yu-Tong Li ◽  
Jian-Wei Wang
Keyword(s):  
Conceptual Design ◽  
Design Process ◽  
Quotient Space ◽  
Basic Structure ◽  
Basic Operation ◽  
Decomposition Tree ◽  
Function Decomposition ◽  
Design Variables ◽  
Set Up

This paper presents a novel indirect matching approach between the function layer and the form layer to enhance the capability for the FBS method to obtain the creative conceptual design results. Firstly, the basic operation actions set, which is composed of the basic operation actions obtained by decomposing each function in the lowest level of the function decomposition tree in the FBS model into the sub-functions, in the function layer is regrouped dynamically. This behavior regroup process has introduced the new design variables into the conceptual design process and leads the behavior creativity to produce. On the other hand, considering the multi-functions for each basic structure to have and representing these functions with the basic operation actions, then the basic operation actions set in the form layer is set up. Dynamic regrouping this set in the form layer, the new design variables has been introduced into the conceptual design process, and leads the form creativity to produce. Through the above behavior-form double directions creative process, the solution scope of the conceptual design is enlarged obviously. Therefore, the method present in this paper has enough capability to obtain the creative conceptual results. Furthermore, the model presented in this paper is represented with the quotient space mathematically. The case study has shown that in the function layer, through adjusting the attribute function, which determines the partition grain of the basic operation actions set in the function layer or in the form layer, the new behaviors can be generated.

Optimal Scheduling of Control Surfaces Flexible Wings to Reduce Induced Drag

2006 ◽  
Vol 43 (6) ◽  
pp. 1655-1661 ◽  
Author(s):  
Raymond M. Kolonay ◽  
Franklin E. Eastep
Keyword(s):  
Optimal Scheduling ◽  
Flexible Wings ◽  
Induced Drag ◽  
Control Surfaces
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