scholarly journals Computational fluid dynamics-based approach for low-order models of propelling nozzle performance

2019 ◽  
Vol 233 (13) ◽  
pp. 4879-4894
Author(s):  
Aws Al-Akam ◽  
Theoklis Nikolaidis ◽  
David G MacManus
Keyword(s):  
Pressure Ratio ◽  
Navier Stokes ◽  
Design Stage ◽  
Preliminary Design ◽  
Thrust Coefficient ◽  
Contraction Ratio ◽  
Half Angle ◽  
Preliminary Design Stage ◽  
Nozzle Configuration ◽  
Low Order

At the preliminary design stage for an aero-engine, the evaluation of the nozzle performance is an important aspect as it affects the overall engine cycle behaviour. Currently, there is a lack of systematic, extensive data on the nozzle performance and its dependence on the geometric and aerodynamic aspects. This paper presents a method that can be used to build characteristic maps for a nozzle as a function of a number of geometric and aerodynamic parameters. The proposed method encompasses the design of a nozzle configuration, a parameterisation of the nozzle pressure ratio, nozzle contraction ratio, plug half-angle (β), mesh generation, and an aerodynamic assessment using the Favre-averaged Navier–Stokes method. The method has been validated against experimental performance data of a plug nozzle configuration and then used for the aerodynamic assessment. The derived nozzle maps show that the thrust coefficient ( Cfg) for this type of nozzle is significantly sensitive to the combined effect of the variation of the proposed parameters on the nozzle performance. These maps were used to build low-order models to predict Cfg, using response surface methods. The performance was assessed, and the results show that these low-order methods are capable of providing Cfg estimates with sufficient accuracy for use in preliminary design assessments.

scholarly journals AERODYNAMIC LOAD OF AN AIRCRAFT WITH A HIGHLY ELASTIC WING

2017 ◽  
Vol 57 (4) ◽  
pp. 272
Author(s):  
Pavel Schoř
Keyword(s):  
Navier Stokes ◽  
Design Stage ◽  
Computational Time ◽  
Aerodynamic Load ◽  
Preliminary Design ◽  
Elastic State ◽  
Preliminary Design Stage ◽  
Evaluation Stage ◽  
Load Evaluation

In this article, a method for calculation of air loads of an aircraft with an elastic wing is presented. The method can predict a redistribution of air loads when the elastic wing deforms. Unlike the traditional Euler or Navier-Stokes CFD to FEM coupling, the method uses 3D panel method as a source of aerodynamic data. This makes the calculation feasible on a typical recent workstation. Due to a short computational time and low hardware demands this method is suitable for both the preliminary design stage and the load evaluation stage. A case study is presented. The study compares a glider wing performing a pull maneuver at both rigid and and elastic state. The study indicates a significant redistribution of air load at the elastic case.

Low Fidelity Design and Analysis Parametric Tool for General Centrifugal Compressors

2019 ◽  
Author(s):  
Sai Muppana ◽  
Kiran Siddappaji ◽  
Shaaban Abdallah ◽  
Mark Turner
Keyword(s):  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Pressure Ratio ◽  
Design Stage ◽  
Analysis Tool ◽  
Preliminary Design ◽  
Centrifugal Compressors ◽  
Preliminary Design Stage ◽  
Successful Design ◽  
Definition Of

Abstract Performance prediction and blade generation in a preliminary design stage of centrifugal compressors is critical to have a successful design. In this paper, a one-dimensional meanline design and analysis tool has been developed for single-rotor and novel multi-rotor centrifugal impellers. Loss models used for performance prediction of single stage compressors have been extended to single hub multi-rotor compressors to evaluate isentropic efficiency and pressure ratio. Stage conditions like work ratio and stator turning angle are given as input parameters and the tool computes flow properties along the meanline and also, generates velocity triangles, streamlines, smooth definition of blade angles at different spanwise sections. The tool acts a preprocessor for Tblade3 which is an in-house 3D parametric blade geometry generator to create blades. A 0D tool has been developed for multi-rotor impellers to provide an estimate of work ratio. 0D coupled with 1D tool can provide a good preliminary design point. The process of 0D to blade generation has been automated enabling it to connect with high-fidelity analysis. The motivation to create this tool is to calculate flow angles, metal angles, velocity triangles, ease of parametric modification and reduce aero-design cycle time. This tool is modular which adds the flexibility of capability extension. The code is validated with DLR centrifugal compressor experimental data. The 1D tool is also used to calculate performance and blade angles for the novel single hub multi-rotor centrifugal compressor demonstrating the versatility of the low fidelity tool. The tool suite is written in Python and is open source https://github.com/msaisiddhartha/CIMdes.

scholarly journals Uniform deformation design of outrigger braced skyscrapers: A simplified method for the preliminary design stage

Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 395-405
Author(s):  
Arsalan Alavi ◽  
Elena Mele ◽  
Reza Rahgozar ◽  
Ehsan Noroozinejad Farsangi ◽  
Izuru Takewaki ◽  
...  
Keyword(s):  
Design Stage ◽  
Preliminary Design ◽  
Uniform Deformation ◽  
Simplified Method ◽  
Preliminary Design Stage

An Approximate Method for Intact Stability of Fishing Vessels

1999 ◽  
Vol 36 (03) ◽  
pp. 171-174
Author(s):  
Hüseyin Yilmaz ◽  
Abdi Kükner
Keyword(s):  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Ship Stability ◽  
Fishing Vessels ◽  
Initial Stability ◽  
Intact Stability ◽  
Preliminary Design Stage ◽  
Reduce Risk ◽  
Vessel Stability

It is well known that stability is the most important safety requirement for ships. One should have some information on ship stability at the preliminary design stage in order to reduce risk. Initial stability of ships is an important criterion and can be closely evaluated in terms of form parameters and vertical center of gravity. In this study, using some sample ship data, approximate formulations are derived by means of regression analysis for the calculations expressed in terms of ship preliminary design parameters that can easily provide approximate GM calculations. Thus designers can be provided with ship stability at the preliminary design stage, and also a set of appropriate design parameters for improving vessel stability can easily be determined.

scholarly journals Fatigue life prediction in a door hinge system under uni-axial and multi-axial loading conditions

2021 ◽  
Author(s):  
Sacheen Bekah
Keyword(s):  
Axial Loading ◽  
Fatigue Analysis ◽  
Design Stage ◽  
Fe Model ◽  
Preliminary Design ◽  
Standard Requirement ◽  
Ground Vehicle ◽  
Design Engineers ◽  
Door Hinge ◽  
Preliminary Design Stage

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.

scholarly journals Fatigue life prediction in a door hinge system under uni-axial and multi-axial loading conditions

2021 ◽  
Author(s):  
Sacheen Bekah
Keyword(s):  
Axial Loading ◽  
Fatigue Analysis ◽  
Design Stage ◽  
Fe Model ◽  
Preliminary Design ◽  
Standard Requirement ◽  
Ground Vehicle ◽  
Design Engineers ◽  
Door Hinge ◽  
Preliminary Design Stage

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.

scholarly journals An Approximate Method for Calculation of Mean Statistical Value of Ship Service Speed on a Given Shipping Line , Useful in Preliminary Design Stage

2015 ◽  
Vol 22 (1) ◽  
pp. 28-35
Author(s):  
Katarzyna Żelazny
Keyword(s):  
Wind Waves ◽  
Parametric Method ◽  
Weather Conditions ◽  
Economic Effects ◽  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Screw Propeller ◽  
Calm Water ◽  
Preliminary Design Stage

Abstract During ship design, its service speed is one of the crucial parameters which decide on future economic effects. As sufficiently exact calculation methods applicable to preliminary design stage are lacking the so called contract speed which a ship reaches in calm water is usually applied. In the paper [11] a parametric method for calculation of total ship resistance in actual weather conditions (wind, waves, sea current), was presented. This paper presents a parametric model of ship propulsion system (screw propeller - propulsion engine) as well as a calculation method, based on both models, of mean statistical value of ship service speed in seasonal weather conditions occurring on shipping lines. The method makes use of only basic design parameters and may be applied in preliminary design stage.

Standard Outfit Package Units in the LPD 17 Ship Design: A Production Impact Study

1995 ◽  
Vol 11 (04) ◽  
pp. 252-263
Author(s):  
Walter L. Christensen ◽  
Philip C. Koenig
Keyword(s):  
Production Scheduling ◽  
Ship Design ◽  
Design Stage ◽  
Traditional Practices ◽  
Preliminary Design ◽  
Wide Range ◽  
Preliminary Design Stage ◽  
And Performance ◽  
Assessment Problems ◽  
Material Ordering

Standard outfit package units for reverse osmosis plants, fire pumps, steering gear, and sanitary spaces were proposed for the LPD 17 amphibious transport dock ship design. The ship was in the preliminary design stage, and it was necessary to determine how this shift to outfit modularity would affect the ship procurement program. Because the use of package units would not have a significant impact on the overall characteristics and performance of the ship, the focus of the investigation was on material ordering and production scheduling. The analysis took account of zone-area-stage outfitting methods and also more traditional practices. With either approach, it was found that the package units did not present any schedule or procurement problems This particular study was focused on a very specific issue, but the approach is applicable to a wide range of production impact assessment problems.

An Approximate Method for Cross Curves of Cargo Vessels

2001 ◽  
Vol 38 (02) ◽  
pp. 92-94
Author(s):  
Huseyin Yilmaz ◽  
Mesut Giiner
Keyword(s):  
Prediction Method ◽  
Design Stage ◽  
Series Data ◽  
Design Parameters ◽  
Preliminary Design ◽  
Hull Form ◽  
Beam Depth ◽  
Preliminary Design Stage ◽  
The Mathematical Model ◽  
Load Conditions

In this study, a formula is presented to estimate cross curves of cargo vessels and to predict statical stability at the preliminary design stage of the vessel. The predictive technique is obtained by regression analysis of systematically varied cargo vessel series data. In order to achieve this procedure, some cargo vessel forms are generated using Series-60. The mathematical model in this predictive technique is constructed as a function of design parameters such as length, beam, depth, draft, and block coefficient. The prediction method developed in this work can also be used to determine the effect of specific hull form parameters and the load conditions on stability of cargo vessels. The present method is applied to a cargo vessel and then the results of the actual ship are compared with those of regression values.

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