Development of a preliminary design tool for rotary wing aircrafts

2022 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Filipe Szolnoky Ramos Pinto Cunha ◽  
Tomás Figueiredo Ventura Pimentel Fontes
Keyword(s):  
Design Tool ◽  
Preliminary Design ◽  
Rotary Wing

Using CFD to Enhance the Preliminary Design of High-Pressure Steam Turbines

2013 ◽  
Author(s):  
Juri Bellucci ◽  
Federica Sazzini ◽  
Filippo Rubechini ◽  
Andrea Arnone ◽  
Lorenzo Arcangeli ◽  
...  
Keyword(s):  
High Pressure ◽  
Steam Turbine ◽  
Design Tool ◽  
Tip Clearance ◽  
Large Set ◽  
Preliminary Design ◽  
Steam Turbines ◽  
High Pressure Steam ◽  
Wide Range ◽  
Pressure Steam

This paper focuses on the use of the CFD for improving a steam turbine preliminary design tool. Three-dimensional RANS analyses were carried out in order to independently investigate the effects of profile, secondary flow and tip clearance losses, on the efficiency of two high-pressure steam turbine stages. The parametric study included geometrical features such as stagger angle, aspect ratio and radius ratio, and was conducted for a wide range of flow coefficients to cover the whole operating envelope. The results are reported in terms of stage performance curves, enthalpy loss coefficients and span-wise distribution of the blade-to-blade exit angles. A detailed discussion of these results is provided in order to highlight the different aerodynamic behavior of the two geometries. Once the analysis was concluded, the tuning of a preliminary steam turbine design tool was carried out, based on a correlative approach. Due to the lack of a large set of experimental data, the information obtained from the post-processing of the CFD computations were applied to update the current correlations, in order to improve the accuracy of the efficiency evaluation for both stages. Finally, the predictions of the tuned preliminary design tool were compared with the results of the CFD computations, in terms of stage efficiency, in a broad range of flow coefficients and in different real machine layouts.

Evaluating Mobility Behavior of Fluid Filled Fiber-Reinforced Elastomeric Enclosures

2012 ◽  
Author(s):  
Girish Krishnan ◽  
Joshua Bishop-Moser ◽  
Charles Kim ◽  
Sridhar Kota
Keyword(s):  
Large Class ◽  
Power Density ◽  
Cost Effective ◽  
Design Tool ◽  
Preliminary Design ◽  
Fiber Reinforced ◽  
Soft Robots ◽  
Large Power ◽  
Mobility Behavior ◽  
Narrow Class

Fluid filled Fiber Reinforced Elastomeric Enclosures (FREE) have been popular choices for actuators in prosthetics and soft robots owing to their large power density and cost effective manufacturing. While a narrow class of FREEs known as McKibben’s actuators have been extensively studied, there is a wide unexplored class that could be potentially used as actuators and load bearing members. This paper analyzes the mobility of a large class of FREEs based on simple geometric relationships that originate due to the inextensibility of fibers and incompressibility of fluids. The analysis conducted on various families of fibers reveal certain configurations that are locked under fluidic actuation. Furthermore the analysis reveals unrestricted motion in certain directions (freedom) and restrictions in certain other directions (constraint). Such an analysis is deemed to be useful as a preliminary design tool to pick the appropriate geometry for use in design of soft robots and actuators.

Predicting the Profile Loss of High-Lift Low Pressure Turbines

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
John D. Coull ◽  
Howard P. Hodson
Keyword(s):  
Boundary Layer ◽  
Velocity Distribution ◽  
Low Pressure ◽  
Design Tool ◽  
Surface Boundary ◽  
Preliminary Design ◽  
Suction Surface ◽  
Surface Boundary Layer ◽  
Blade Loading ◽  
Profile Loss

The overall efficiency of low pressure turbines is largely determined by the two-dimensional profile loss, which is dominated by the contribution of the suction surface boundary layer. This boundary layer typically features a laminar separation bubble and is subjected to an inherently unsteady disturbance environment. The complexity of the flow behavior makes it difficult to numerically predict the profile loss. To address this problem, an empirical method is proposed for predicting the boundary layer integral parameters at the suction surface trailing edge, allowing the profile loss to be estimated. Extensive measurements have been conducted on a flat plate simulation of the suction surface boundary layer. The disturbance environment of real machines was modeled using a moving bar wake generator and a turbulence grid. From this data set, empirically based methods have been formulated using physical principles for the prediction of the momentum thickness and shape factor at the suction surface trailing edge. The predictions of these methods may be used to estimate the profile loss of a given cascade, which achieves reasonable agreement with the available data. By parameterizing the shape of the suction surface velocity distribution, the method is recast as a preliminary design tool. Powerfully, this may be used to guide the selection of the key design parameters (such as the blade loading and velocity distribution shape) and enables a reasonable estimation of the unsteady profile loss to be made at a very early stage of design. To illustrate the capabilities of the preliminary design tool, different styles of velocity distribution are evaluated for fixed blade loading and flow angles. The predictions suggest that relatively “flat-top” designs will have the lowest profile loss but good performance can also be achieved with front-loaded “peaky” distributions. The latter designs are more likely to have acceptable incidence tolerance.

scholarly journals A zonal safety analysis methodology for preliminary aircraft systems and structural design

2018 ◽  
Vol 122 (1255) ◽  
pp. 1330-1351 ◽  
Author(s):  
Z. Chen ◽  
J. P. Fielding
Keyword(s):  
Failure Modes ◽  
Hazard Analysis ◽  
Fault Tree Analysis ◽  
Cost Effective ◽  
Safety Analysis ◽  
Design Tool ◽  
Assessment Process ◽  
Design Stage ◽  
Preliminary Design

ABSTRACTZonal Safety Analysis (ZSA) is a major part of the civil aircraft safety assessment process described in Aerospace Recommended Practice 4761 (ARP4761). It considers safety effects that systems/items installed in the same zone (i.e. a defined area within the aircraft body) may have on each other. Although the ZSA may be conducted at any design stage, it would be most cost-effective to do it during preliminary design, due to the greater opportunity for influence on system and structural designs and architecture. The existing ZSA methodology of ARP4761 was analysed, but it was found to be more suitable for detail design rather than preliminary design. The authors therefore developed a methodology that would be more suitable for preliminary design and named it the Preliminary Zonal Safety Analysis (PZSA). This new methodology was verified by means of the use of a case study, based on the NASA N3-X project. Several lessons were learnt from the case study, leading to refinement of the proposed method. These lessons included focusing on the positional layout of major components for the zonal safety inspection, and using the Functional Hazard Analysis (FHA)/Fault Tree Analysis (FTA) to identify system external failure modes. The resulting PZSA needs further refinement, but should prove to be a useful design tool for the preliminary design process.

A Preliminary Design Tool for Pretwisted, Tapered Beams or Turbine Blades

1980 ◽  
Vol 102 (4) ◽  
pp. 742-748 ◽  
Author(s):  
L. L. Durocher ◽  
J. Kane
Keyword(s):  
Turbine Blades ◽  
Three Dimensional ◽  
Design Tool ◽  
Preliminary Design ◽  
Current Formulation ◽  
Torsional Coupling ◽  
Final Design ◽  
Dimensional Finite Element ◽  
Loading Effects ◽  
Three Dimensional Finite Element

A strength-of-materials approach is used to develop an approximate stiffness matrix for a uniformly-pretwisted beam segment. The beam element is a 12 degree-of-freedom member that includes shear effects, eccentric loading effects, axial-torsional and bending-torsional coupling, and the torsional stiffening effect of the natural pretwist. The current formulation can be employed as an inexpensive preliminary design tool for pretwisted blading that is suitable for implementation on low-core computer graphics systems. After obtaining a workable geometry, final design optimization can be performed by utilizing more sophisticated, and expensive, three-dimensional finite element models.

The ranking of efficiency of structural layouts using form factors Part 1: Design for stiffness

1998 ◽  
Vol 212 (2) ◽  
pp. 117-128 ◽  
Author(s):  
S C Burgess
Keyword(s):  
Load Transfer ◽  
Form Factors ◽  
Design Tool ◽  
Preliminary Design ◽  
Load Case ◽  
Structural Efficiency ◽  
Simply Supported ◽  
Stiffness Design ◽  
Loaded Structure

This paper presents a method for ranking the mass efficiency of simple structural layouts for stiffness design using form factors. Form factors are derived for three different frameworks and seven different beams for an example load case of a simply supported and centrally loaded structure. The form factors show how structural efficiency is affected by four different design aspects: (a) severity of height constraint, (b) uniformity of stress, (c) utilization of height and (d) principle of load transfer. Form factors can be used as a preliminary design tool to help select and design structural concepts.

Use of Athena Vortex Lattice for Preliminary Hydrofoil Design

2015 ◽  
Author(s):  
Katelynne R. Burrell ◽  
Joshua P. Sykes ◽  
Timothy B. Dewhurst ◽  
Zhaohui Qin
Keyword(s):  
High Speed ◽  
Vortex Lattice ◽  
Design Tool ◽  
Preliminary Design ◽  
Reference Guide ◽  
The Past ◽  
Lifting Surfaces ◽  
Lift And Drag ◽  
Design Options ◽  
Short Time

The purpose of this paper is to demonstrate the extent to which the Athena Vortex Lattice program (AVL) is useful in the design of a hydrofoil system for a solar boat. Cedarville University has won the Solar Splash Collegiate World Championship of Solar Boating 8 times in the past 12 years, and was the top university in the Top Class of the 2012 DONG Energy Solar Challenge in the Netherlands. The three main events of the Solar Splash Competition are the high-speed Slalom and Sprint events, and the longer Endurance event. In the past Cedarville has attempted to design and use hydrofoils for the Endurance event without success. Computational Fluid Dynamics (CFD) analysis for a hydrofoil system was conducted by Neola Putnam (2013 team member) using ANSYS’s CFD software, Fluent. Putnam worked with single phase flow modeling 3D hydrofoils. Fluent analysis can be a long and complicated process requiring hours of meshing followed by hours of CPU time for analysis. AVL, as an alternative, is a less complicated program allowing for simple generation of a geometry file. This program also takes a comparatively short time to analyze the imported geometry file. Thus, if AVL reliably predicts lift and drag, it could be used as a preliminary design tool to quickly assess various design options. AVL is a program which models lifting surfaces as vortex lattice sheets to determine the flight characteristics of the surface. The program is written in Fortran and is an inviscid solver. The AVL3.30 User Primer is a reference guide on how to use the program and was used extensively by the authors of this paper when learning to use AVL. Cedarville University also partnered with the company Sea Land Aire Technologies Inc.in Jackson Michigan for aid in using AVL as a design tool. The tool was recommended to Cedarville University by Sea Land Aire as a product which might be of interest to our team in the design of a hydrofoil system. AVL is potentially beneficial to the Cedarville University Solar Boat team in the preliminary design phase of a hydrofoil system. The content of this paper demonstrates the correlation between results from AVL and Fluent analysis for a 2D NACA 4412 foil. Secondly, the paper demonstrates comparable results from AVL for 3Danalysiswith published experimental results. The following sections discuss the use of AVL as a preliminary design tool, and the overall recommendation of the authors as to further use of AVL by Cedarville University in the design of a hydrofoil system.

Automated Combustor Preliminary Design Using Tools of Different Fidelity

2013 ◽  
Author(s):  
Andreas Angersbach ◽  
Dieter Bestle ◽  
Ruud Eggels
Keyword(s):  
Design Process ◽  
Design Tool ◽  
Thermal Design ◽  
Design Stage ◽  
Air Distribution ◽  
Preliminary Design ◽  
Cfd Analysis ◽  
Fuel Injector ◽  
Geometry Model ◽  
3D Geometry

The design of a modern aero-engine combustor is a highly complex and multi-disciplinary task. The combustor design is strongly driven by severe emission regulations and ACARE 2020/2050 goals. Furthermore, new designs have to be developed within short turn-around times. This paper describes a novel approach of an automated preliminary aero-thermal design process of a rich-burn combustor combining 1D, 2D and 3D design tools in order to speed up the design loop and provide improved combustor designs in an early design stage. The automated design process includes a knowledge-based preliminary design tool, an 1D network solver, a parametric 3D geometry model, a meshing tool, and 3D-CFD analysis. At first, a preliminary combustor design is created based on industrial in-house design rules. The preliminary design tool provides a 2D geometry model and cooling layout. It is coupled with an 1D network solver to calculate the air distribution inside the combustor. The design process includes two state-of-the-art combustor cooling schemes, effusion cooling and impingement effusion cooling. An air flow model for both cooling schemes is created within the network, respectively. The computed air distribution is subsequently used to generate boundary conditions for a 3D-CFD analysis. To perform the CFD calculations, a parametric 3D geometry model of a combustor sector has been developed based on a 2D preliminary design which takes into account mixing port properties, fuel injector, and combustor wall cooling. After an automated meshing 3D-CFD computations are performed. As a result, quick automatic estimation of combustor emissions, size and efficiency can be obtained within the design process. A CFD parameter study of a mixing port variation and their effect on the emissions of NOx and soot is performed using the described layout process.

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