scholarly journals Modified Virtual Blade Method for Propeller Modelling

2020 ◽  
Vol 22 (2) ◽  
pp. 603-618
Author(s):  
Mateusz Stajuda ◽  
Damian Obidowski ◽  
Maciej Karczewski ◽  
Krzysztof Jóźwik
Keyword(s):  
Numerical Models ◽  
Original Method ◽  
Computational Time ◽  
Model Accuracy ◽  
Computational Point ◽  
Design And Optimization ◽  
Rotating Blades ◽  
Propeller Design ◽  
Comparable Accuracy ◽  
Propeller Performance

AbstractThe emergence of large, propeller-based aircraft has revived interest in propeller design and optimization with the use of numerical methods. The flow complexity and computational time necessary to solve complicated flow patterns trailing behind rotating blades, created a need for faster than fully resolved 3D CFD, yet comparably accurate methods for validating multiple design points in shorter time. Improved Virtual Blade Method (VBM) for 2-bladed propeller, including method implementation, analysis and validation against 3D numerical and experimental data is presented. The study introduces adjustments to the original method, accounting for differences between VBM and fully resolved numerical models. These modifications prove to increase the model accuracy for the propeller under consideration and could potentially be applied for different blade configurations as well. The modified Virtual Blade Method allows one to compute the propeller performance with comparable accuracy to 3D CFD computation using only 10% of time needed for one computational point.

Advanced Virtual Prototyping of Axial Piston Machines

2016 ◽  
Author(s):  
Rene Chacon ◽  
Monika Ivantysynova
Keyword(s):  
Numerical Models ◽  
Virtual Prototyping ◽  
Valve Plate ◽  
Cylinder Block ◽  
Plate Interface ◽  
Design And Optimization ◽  
Swash Plate ◽  
Axial Piston Machine ◽  
Axial Piston ◽  
Plate Type

This paper explains how a combination of advanced multidomain numerical models can be employed to design an axial piston machine of swash plate type within a virtual prototyping environment. Examples for the design and optimization of the cylinder block/valve plate interface are presented.

Design and Analysis Software for Propellers

2013 ◽  
Author(s):  
Rajeevalochanam Prathapanayaka ◽  
Nanjundaiah Vinod Kumar ◽  
Krishnamurthy Settisara Janney ◽  
Hari Krishna Nagishetty
Keyword(s):  
Performance Analysis ◽  
Reynolds Numbers ◽  
Performance Comparison ◽  
High Lift ◽  
Low Reynolds Numbers ◽  
Propeller Design ◽  
Air Vehicle ◽  
Loss Method ◽  
Propeller Performance ◽  
Air Vehicles

Recent interest in the field of micro and nano scale air vehicles attracted the attention of many researchers all over the world. The challenge associated with these classes of vehicles is to develop efficient miniaturized components. There are different types of micro and nano air vehicles out of which fixed wing micro air vehicle is one of them. Propulsion system for most of the fixed wing MAVs is propeller driven by an electric motor powered by a battery. The endurance of the MAV mainly depends on the performance of these two components. Hence there is a scope to improve the performance of the propeller and motor. Efficient propeller design and its performance analysis are an iterative process and time consuming. In the present study, to ease the process of propeller design and analysis NALPROPELLER code has been developed using MATLAB. This code is based on minimum induced loss theory presented by E.E.Larrabee to generate planform, blade element momentum theory along with Prandtl hub-tip loss model for overall performance analysis and the performance plots could be viewed in the GUI windows. The code consists of three modules namely single airfoil design, multi airfoil design and analysis module. This code is compared with one of the propeller design and analysis code available in the internet JavaProp by Martin Hepperle, which is also based on minimum induced loss method. From literature Eppler 193 airfoil show high lift to drag ratios at low Reynolds numbers [16]. Eppler-193 airfoil is used in the evaluation of propeller performance. A four inch diameter, two bladed, fixed pitch propeller is designed and analysed using this code. The design is compared with one of the design software JavaProp available online as an open source. A poly urethane casting propeller is fabricated based on the design. The performance comparison of the NALPROPELLER code, JavaProp and 3D CFD analysis is presented and discussed.

scholarly journals Wavelet-based spatial comparison technique for analysing and evaluating two-dimensional geophysical model fields

2012 ◽  
Vol 5 (1) ◽  
pp. 223-230 ◽  
Author(s):  
S. Saux Picart ◽  
M. Butenschön ◽  
J. D. Shutler
Keyword(s):  
Satellite Data ◽  
Fishery Management ◽  
Numerical Models ◽  
Spatial Scales ◽  
Marine Ecosystem ◽  
Original Method ◽  
Precipitation Forecast ◽  
Spatial And Temporal Scales ◽  
Geographical Patterns ◽  
Marine Ecosystem Model

Abstract. Complex numerical models of the Earth's environment, based around 3-D or 4-D time and space domains are routinely used for applications including climate predictions, weather forecasts, fishery management and environmental impact assessments. Quantitatively assessing the ability of these models to accurately reproduce geographical patterns at a range of spatial and temporal scales has always been a difficult problem to address. However, this is crucial if we are to rely on these models for decision making. Satellite data are potentially the only observational dataset able to cover the large spatial domains analysed by many types of geophysical models. Consequently optical wavelength satellite data is beginning to be used to evaluate model hindcast fields of terrestrial and marine environments. However, these satellite data invariably contain regions of occluded or missing data due to clouds, further complicating or impacting on any comparisons with the model. This work builds on a published methodology, that evaluates precipitation forecast using radar observations based on predefined absolute thresholds. It allows model skill to be evaluated at a range of spatial scales and rain intensities. Here we extend the original method to allow its generic application to a range of continuous and discontinuous geophysical data fields, and therefore allowing its use with optical satellite data. This is achieved through two major improvements to the original method: (i) all thresholds are determined based on the statistical distribution of the input data, so no a priori knowledge about the model fields being analysed is required and (ii) occluded data can be analysed without impacting on the metric results. The method can be used to assess a model's ability to simulate geographical patterns over a range of spatial scales. We illustrate how the method provides a compact and concise way of visualising the degree of agreement between spatial features in two datasets. The application of the new method, its handling of bias and occlusion and the advantages of the novel method are demonstrated through the analysis of model fields from a marine ecosystem model.

Aerodynamic design and optimization of propellers for multirotor

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Witold Artur Klimczyk
Keyword(s):  
Structural Integrity ◽  
Navier Stokes ◽  
Optimization Approach ◽  
Minimum Thickness ◽  
Design Problems ◽  
Content Type ◽  
Design And Optimization ◽  
Propeller Design ◽  
Unmanned Air Vehicle ◽  
Propeller Blades

Purpose This paper aims to present a methodology of designing a custom propeller for specified needs. The example of propeller design for large unmanned air vehicle (UAV) is considered. Design/methodology/approach Starting from low fidelity Blade Element (BE) methods, the design is obtained using evolutionary algorithm-driven process. Realistic constraints are used, including minimum thickness required for stiffness, as well as manufacturing ones – including leading and trailing edge limits. Hence, the interactions between propellers in hex-rotor configuration, and their influence on structural integrity of the UAV are investigated. Unsteady Reynolds-Averaged Navier–Stokes (URANS) are used to obtain loading on the propeller blades in hover. Optimization of the propeller by designing a problem-specific airfoil using surrogate modeling-driven optimization process is performed. Findings The methodology described in the current paper proved to deliver an efficient blade. The optimization approach allowed to further improve the blade efficiency, with power consumption at hover reduced by around 7%. Practical implications The methodology can be generalized to any blade design problem. Depending on the requirements and constraints the result will be different. Originality/value Current work deals with the relatively new class of design problems, where very specific requirements are put on the propellers. Depending on these requirements, the optimum blade geometry may vary significantly.

Integrated Thermomechanical Design and Optimization of BGA Packages Using Genetic Algorithm

Volume 4 ◽  
2004 ◽  
Author(s):  
Hamid A. Hadim ◽  
Tohru Suwa
Keyword(s):  
Genetic Algorithm ◽  
Thermal Strain ◽  
System Level ◽  
Multidisciplinary Design ◽  
Design Stage ◽  
Computational Time ◽  
Design Parameters ◽  
Package Design ◽  
Early Design Stage ◽  
Design And Optimization

A new multidisciplinary design and optimization methodology in electronics packaging is presented. A genetic algorithm combined with multi-disciplinary design and multi-physics analysis tools are used to optimize key design parameters. This methodology is developed to improve the electronic package design process by performing multidisciplinary design and optimization at an early design stage. To demonstrate its capability, the methodology is applied to a Ball Grid Array (BGA) package design. Multidisciplinary criteria including thermal, thermal strain, electromagnetic leakage, and cost are optimized simultaneously. A simplified routability analysis criterion is treated as a constraint. The genetic algorithm is used for systematic design optimization while reducing the total computational time. The present methodology can be applied to any electronics product design at any packaging level from the chip level to the system level.

Design and manufacture of propellers for small unmanned aerial vehicles

2016 ◽  
Vol 4 (4) ◽  
pp. 228-245 ◽  
Author(s):  
Brian Rutkay ◽  
Jeremy Laliberté
Keyword(s):  
Additive Manufacturing ◽  
Wind Tunnel ◽  
Unmanned Aerial Vehicles ◽  
Wind Tunnel Testing ◽  
Performance Requirements ◽  
Propeller Design ◽  
Aerial Vehicles ◽  
Aircraft Performance ◽  
Design And Manufacture ◽  
Propeller Performance

The objective of this research was to develop a process for the design and manufacture of mission- and aircraft-specific propellers for small unmanned aerial vehicles. This objective was met by creating a computer program to design a propeller that meets user-defined aircraft performance requirements within the limitations of the electric motor, user-selected materials, and manufacturing methods. A comprehensive review of prior UAV propeller design and additive manufacturing for small propellers is also presented in this paper. The use of additive manufacturing (3D printing) in making flightworthy propellers was explored through material testing, manufacturing trials, and by testing the propellers under simulated flight conditions in a wind tunnel. It was found that the propeller performance generated nearly the predicted design thrust but the efficiency and power consumption could not be accurately measured with the present test setup. While flight testing was not completed at this time, ground and wind tunnel testing were sufficient to demonstrate the feasibility of producing flightworthy propellers using additive manufacturing.

Effects of Wind Environment on Propeller Performance of Multirotor Drone in Hover

2019 ◽  
Author(s):  
Motonao Murakami ◽  
Hiroyuki Abe ◽  
Hikaru Aono ◽  
Hitoshi Ishikawa
Keyword(s):  
Flow Velocity ◽  
Figure Of Merit ◽  
Cross Flow ◽  
Force Transducer ◽  
Test Cases ◽  
Torque Measurement ◽  
Propeller Design ◽  
Starting Point ◽  
Cross Flow Velocity ◽  
Propeller Performance

Abstract The purpose of this study is to understand the effect of cross flow and fluctuating flow on the propeller performance of MAV. This study especially has focused on the propeller performance during hovering flight under several cross flow velocity in actual flight conditions. We investigated four test cases of propellers with different starting point of design. The thrust and the torque of each propeller were experimentally measured by using the force transducer in wind tunnel. Figure of Merit (FM) of each propeller were evaluated based on the thrust and the torque measurement. The results showed that low cross flow velocity reduced FM. However, high cross flow velocity improved FM. Fluctuating flow yielded the change of FM with time. Furthermore, it was found that the starting point of the propeller design had a great effect on FM under wind environments.

Heat Transfer Computations for Turbine Blade Airfoils

1996 ◽  
Author(s):  
Jamel Slimani ◽  
Pascale Kulisa
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Separation Bubble ◽  
Turbine Blades ◽  
Flow Characteristics ◽  
Equation Model ◽  
Computational Time ◽  
Design And Optimization ◽  
Wall Flows ◽  
Turbine Blade Design

The design and optimization of turbine blades subjected to high temperature flows require the prediction of aerodynamic and thermal flow characteristics. A computation of aerothermal viscous flow model has been developed suitable for the turbine blade design process. The computational time must be reduced to allow intensive use in an industrial framework. The physical model is based on a compressible boundary layer approach, and the turbulence is a one-equation model. Special attention has been paid to the influence of wall curvature on the turbulence modelling. Tests were performed on convex wall flows to validate the turbulence model. Turbine blade configurations were then computed. These tests include most difficulties that can be encountered in practice : laminar-turbulent transition, separation bubble, strong accelerations, shock wave. Satisfactory predictions of the wall heat transfer are observed.

Comparative Analysis of Two Numerical Methods of Rollover Simulation of a Semitrailer for Hydrogen Transport

2009 ◽  
Author(s):  
David Valladares ◽  
Luis Castejo´n ◽  
Marco Carrera ◽  
Ramo´n Miralbe´s ◽  
Hugo Malo´n ◽  
...  
Keyword(s):  
Numerical Models ◽  
Experimental Tests ◽  
Hydrogen Transport ◽  
The Finite Element Method ◽  
Great Cost ◽  
Design And Optimization ◽  
Computer Tools ◽  
Sensibility Analysis ◽  
Structural Parts ◽  
Specific Impact

Nowadays, the use of the Finite Element Method [1] by means of simulation computer tools has made possible a substantial step forward in the field of calculation and optimization of vehicle structures. More specifically, these modern calculation tools are achieving great cost reductions corresponding to the experimental tests necessary to verify the appropriate performance of a vehicle in impact cases. On the other hand, great efforts will have to be done to develop correct numerical models for calculation. Once these numerical models have been validated with experimental tests, elimination of experimental costs compensates for these calculation efforts. A greater flexibility in decision making with respect to design and optimization alternatives will be achieved as well. The objective of this paper is to obtain an appropriate test simulation methodology for a specific vehicle and a specific impact case: There have been carried out the simulations of two different rollover test typologies in order to verify an adequate and safe behaviour of a semitrailer designed for hydrogen transport. After results of these two simulations are obtained, they will be compared in order to set which is the most restrictive and therefore the most appropriate. A lightened configuration has been also considered so as to carry out a sensibility analysis of material and thickness of some structural parts over numerical results in both test typologies in order to verify these simulations.

scholarly journals A GIS Tool for Mapping Dam-Break Flood Hazards in Italy

2019 ◽  
Vol 8 (6) ◽  
pp. 250 ◽  
Author(s):  
Raffaele Albano ◽  
Leonardo Mancusi ◽  
Jan Adamowski ◽  
Andrea Cantisani ◽  
Aurelia Sole
Keyword(s):  
Numerical Models ◽  
Technical Skills ◽  
Dam Break ◽  
Propagation Model ◽  
Dam Failure ◽  
Computational Time ◽  
Hazard Mapping ◽  
Flood Hazards ◽  
Proposed Model ◽  
Flood Prone Areas

Mapping the delineation of areas that are flooded due to water control infrastructure failure is a critical issue. Practical difficulties often present challenges to the accurate and effective analysis of dam-break hazard areas. Such studies are expensive, lengthy, and require large volumes of incoming data and refined technical skills. The creation of cost-efficient geospatial tools provides rapid and inexpensive estimates of instantaneous dam-break (due to structural failure) flooded areas that complement, but do not replace, the results of hydrodynamic simulations. The current study implements a Geographic Information System (GIS) based method that can provide useful information regarding the delineation of dam-break flood-prone areas in both data-scarce environments and transboundary regions, in the absence of detailed studies. Moreover, the proposed tool enables, without advanced technical skills, the analysis of a wide number of case studies that support the prioritization of interventions, or, in emergency situations, the simulation of numerous initial hypotheses (e.g., the modification of initial water level/volume in the case of limited dam functionality), without incurring high computational time. The proposed model is based on the commonly available data for masonry dams, i.e., dam geometry (e.g., reservoir capacity, dam height, and crest length), and a Digital Elevation Model. The model allows for rapid and cost-effective dam-break hazard mapping by evaluating three components: (i) the dam-failure discharge hydrograph, (ii) the propagation of the flood, and (iii) the delineation of flood-prone areas. The tool exhibited high accuracy and reliability in the identification of hypothetical dam-break flood-prone areas when compared to the results of traditional hydrodynamic approaches, as applied to a dam in Basilicata (Southern Italy). In particular, the over- and under-estimation rates of the proposed tool, for the San Giuliano dam, Basilicata, were evaluated by comparing its outputs with flood inundation maps that were obtained by two traditional methods whil using a one-dimensional and a two-dimensional propagation model, resulting in a specificity value of roughly 90%. These results confirm that most parts of the flood map were correctly classified as flooded by the proposed GIS model. A sensitivity value of over 75% confirms that several zones were also correctly identified as non-flooded. Moreover, the overall effectiveness and reliability of the proposed model were evaluated, for the Gleno Dam (located in the Central Italian Alps), by comparing the results of literature studies concerning the application of monodimensional numerical models and the extent of the flooded area reconstructed by the available historical information, obtaining an accuracy of around 94%. Finally, the computational efficiency of the proposed tool was tested on a demonstrative application of 250 Italian arch and gravity dams. The results, when carried out using a PC, Pentium Intel Core i5 Processor CPU 3.2 GHz, 8 GB RAM, required about 73 min, showing the potential of such a tool applied to dam-break flood mapping for a large number of dams.

Sign in / Sign up

Export Citation Format

Share Document