A Design Method for High-Speed Propulsor Blades

1998 ◽  
Vol 120 (3) ◽  
pp. 556-562 ◽  
Author(s):  
Paul E. Griffin ◽  
Spyros A. Kinnas
Keyword(s):  
Present Method ◽  
High Speed ◽  
Design Method ◽  
Flow Characteristics ◽  
Optimization Method ◽  
Analysis Method ◽  
Minimum Pressure ◽  
Propeller Design ◽  
Propeller Blades ◽  
Skew Distribution

This study uses a nonlinear optimization method coupled with a vortex lattice cavitating propeller analysis method to design efficient propeller blades. Different constraints are imposed to improve propeller design. Several advancements in the method are shown, including the option for quadratic skew, user specified skew distribution, and a constraint limiting the minimum pressure in wetted regions of the blade. Results for a series of fully wetted runs demonstrate the effectiveness of the constraint on minimum pressure in preventing the onset of bubble or mid-chord cavitation. A comparison of a design in uniform inflow with a design in non-axisymmetric inflow indicates that a propeller designed by the present method in non-axisymmetric inflow has more favorable cavitating flow characteristics than a propeller design assuming uniform inflow. Results are also shown for a series of runs utilizing the cavity constraints. These results indicate that the present method can be used to improve on propeller designs by imposing constraints on the cavity area and cavity volume velocity harmonics, as well as by using a quadratic skew distribution.

Wake and Loss Analysis for a Double Bladed Swept Propeller

2016 ◽  
Author(s):  
Alexandre Capitao Patrao ◽  
Richard Avellán ◽  
Anders Lundbladh ◽  
Tomas Grönstedt
Keyword(s):  
High Speed ◽  
Energy Analysis ◽  
Complex Geometry ◽  
Analysis Method ◽  
Aircraft Wings ◽  
Loss Analysis ◽  
Propeller Wake ◽  
Induced Drag ◽  
Propeller Blades ◽  
Tip Velocity

Inspired by Prandtl’s theory on aircraft wings with minimum induced drag, the authors introduced a double-bladed propeller, the Boxprop, intended for high-speed flight. The basic idea is to join the propeller blades pair-wise at the tip to improve aerodynamics and mechanical properties compared to the conventional propeller. The rather complex geometry of the double blades gives rise to new questions, particularly regarding the aerodynamics. This paper presents a propeller wake energy analysis method which gives a better understanding of the potential performance benefits of the Boxprop and a means to improve its design. CFD analysis of a five bladed Boxprop demonstrated its ability to generate typical levels of cruise thrust at a flight speed of Mach 0.75. The present work shows that the near tip velocity variations in the wake are weaker for this propeller than a conventional one, which is an indication that a counter rotating propeller designed with a Boxprop employed at the front may exhibit lower interaction noise.

The Calculation of Marine Propellers Based on Lifting-Surface Theory

1961 ◽  
Vol 5 (03) ◽  
pp. 1-14
Author(s):  
Pao C. Pien
Keyword(s):  
High Speed ◽  
Design Method ◽  
Design Procedure ◽  
Rate Of Change ◽  
Numerical Work ◽  
Surface Theory ◽  
Marine Propellers ◽  
Propeller Design ◽  
Lifting Surface ◽  
Blade Area

Since the present theoretical propeller design method is based on the lifting-surface theory formulated by Ginzel and Ludwieg, an improvement to this lifting-surface theory is made first. Aside from the fact that the improved lifting-surface theory is more general with respect to blade outline and the loading distribution over the blade area, the most important improvement is in the method of obtaining the induced mean lines. In the new theory the induced mean line at any radius is derived from the down-wash distribution along the entire chord length rather than from the rate of change of the down wash at the middle chord as has been done by Ginzel and Ludwieg. The results obtained from the new method show that the induced mean line at any radius is not a function of the chordwise loading distribution at that radius alone but a function of the loading distribution over the entire blade area and the blade outline. Based on the improved theory a new theoretical propeller design method has been developed. The numerical work involved in this design method has been programmed into a high-speed computer for a special case of uniform chordwise loading distribution. Two design examples have been carried out in accordance with the new design procedure, one with skewed blade and the other with symmetrical blade. The experimental verification of the work presented here will be done in the near future.

Dynamic Analysis and Design Method Study on the Combined-Boom System of Portal Crane

2012 ◽  
Vol 152-154 ◽  
pp. 1645-1649 ◽  
Author(s):  
Yuan Tao Sun ◽  
Duan Li
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Design Method ◽  
Time History ◽  
Analysis Method ◽  
Drive Power ◽  
Analysis And Design ◽  
Whole Process ◽  
Handling Device ◽  
Portal Crane

As a main handling device the portal crane is widely used in port, railroad, etc.The crane handling procedure is mainly carried out through its combined-boom system luffing or swing .In general, in order to reduce drive power and improve the operational performance, the luffing trajectory should meet the design requirement. At the same time, structure stress should be secured in the whole process of handling the cargo. Recently, to deal with more heaver and further cargo, the portal crane is becoming more large-scale. So that the large-scale components such as jib elastic deformation effect on large displacement motion cannot be ignored longer. In addition to the structure high speed motion in the process of handling also make the structure dynamic behaviors spending more obvious specially in the condition of luffing combined with swing. However, the problem for this dynamic behavior brings about to physical design sometimes has no method to solve according to the conventional analysis algorithm and dynamics method. To reduce the deviation caused by the common analysis, design and analysis method based on the multibody is put forward in this thesis. According to the method, the result on the luffing trajectory and stress-time history are analyzed easily. So that it ensure the efficiency and increase the accuracy of the initial design according to the conventional design and analysis method.

Optimization Design Method of High Speed Milling Cutter Based on Axiomatic Design

2010 ◽  
Vol 431-432 ◽  
pp. 314-317
Author(s):  
Bin Jiang ◽  
Jun Jian Ming ◽  
Wei Zhang ◽  
Min Li Zheng
Keyword(s):  
Collaborative Design ◽  
High Speed ◽  
Optimization Design ◽  
Design Method ◽  
Axiomatic Design ◽  
Optimization Method ◽  
Design Requirement ◽  
Milling Cutter ◽  
High Speed Milling ◽  
Function Decomposition

Using the theory of axiomatic design, the optimization method of high speed milling cutter was investigated, and the optimization designs of teeth distribution and dynamic balancing were created by means of function decomposition and grey cluster analysis. Results showed that the method solved effectively the problem of parameters interaction and functions coupling in optimization design of cutter, the effects of simplifying design process and improving collaborative design were validated in development of cutter. Experiments indicated that the vibration in high speed machining aluminum alloy was depressed, the cutter held higher cutting stability, and its cutting performance met the optimization design requirement of high speed milling cutter.

Application of a Numerical Optimization Technique to the Design of Cavitating Propellers in Nonuniform Flow

1997 ◽  
Vol 41 (02) ◽  
pp. 93-107 ◽  
Author(s):  
Shigenori Mishima ◽  
Spyros A. Kinnas
Keyword(s):  
Optimization Algorithm ◽  
High Speed ◽  
Optimization Technique ◽  
Design Parameters ◽  
Nonuniform Flow ◽  
Surface Design ◽  
Sheet Cavitation ◽  
Propeller Design ◽  
Cavity Characteristics ◽  
Propeller Blades

High-speed propulsor blades often experience moderate to substantial amounts of unsteady cavitation, and up to now have been designed via design methods for noncavitating blades combined with methods for the analysis of cavitating flows in a trial-and-error manner. In this paper, a numerical nonlinear optimization algorithm is developed for the automated, systematic design of cavitating blades. The method is first applied to the design of propeller blades in uniform flow. The blade mean camber surface is defined via a cubic B-spline polygon net in order to facilitate the handling of the geometry, and to reduce the number of the design parameters. Noncavitating blade geometries designed by the present method are directly compared with those designed via an existing lifting-line/lifting-surface design approach. Finally, the optimization algorithm is applied to the design of cavitating blades in nonuniform flow. The objective of the design is to obtain maximum propeller efficiency for given conditions by allowing controlled amounts of sheet cavitation. Several constraints on the unsteady cavity characteristics, such as the area of cavity planform and the amplitudes of the cavity volume velocity harmonics, are incorporated in the optimization technique. The effect of the constraints on the efficiency of the propeller design is demonstrated with various test cases.

High Speed Information Network Planning using Stochastic Optimization Method

2013 ◽  
Author(s):  
Ki-Sang Song ◽  
Arun K. Somani
Keyword(s):  
Stochastic Optimization ◽  
Network Design ◽  
Multimedia Information ◽  
High Speed ◽  
Minimum Cost ◽  
Optimization Method ◽  
Multimedia Communication ◽  
Network Design Problem ◽  
Information Network ◽  
Traffic Characteristics

From the 1994 CAIS Conference: The Information Industry in Transition McGill University, Montreal, Quebec. May 25 - 27, 1994.Broadband integrated services digital network (B-ISDN) based on the asynchronous transmission mode (ATM) is becoming reality to provide high speed, multi bit rate multimedia communications. Multimedia communication network has to support voice, video and data traffics that have different traffic characteristics, delay sensitive or loss sensitive features have to be accounted for designing high speed multimedia information networks. In this paper, we formulate the network design problem by considering the multimedia communication requirements. A high speed multimedia information network design alogrithm is developed using a stochastic optimization method to find good solutions which meet the Quality of Service (QoS) requirement of each traffic class with minimum cost.

Designing Popular Classes on Viewboard Public Assessment of Lectures Based on YII Framework

2019 ◽  
Vol 1 (2) ◽  
pp. 144-156
Author(s):  
Indri Handayani ◽  
Erick Febriyanto ◽  
Andrew Jethro
Keyword(s):  
Flow System ◽  
Design Method ◽  
Assessment System ◽  
Student Identity ◽  
Analysis Method ◽  
The Public ◽  
Registration Number ◽  
System Requirements ◽  
Popular Classes ◽  
Observation Method

The lecture support system in Higher Education has information about student identity in each system, such as profile photos, names, NIM (Student Registration Number) and according to system requirements. An assessment on the public viewboard is an Online Assessment System aimed at improving services at Raharja University. However, in the multiplication flow system still has 3 disadvantages, namely, students do not yet have the facility to see the allocation value between friends in one class in one course to be able to improve the results of lecture grades with classmates and also between classes. In class design Popular writers also do five methods, namely the method of analysis, method of literature review, observation method, design method, and then implemented. With the existence of this study, there are 3 Benefits, namely, students can see the value determined by classmates, can improve the value, and lecturers can ensure the value given must be recognized by students.    

scholarly journals Lightweight and maintainable rotary-wing UAV frame from configurable design to detailed design

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110349
Author(s):  
Huiqiang Guo ◽  
Mingzhe Li ◽  
Pengfei Sun ◽  
Changfeng Zhao ◽  
Wenjie Zuo ◽  
...  
Keyword(s):  
Design Method ◽  
Geometric Model ◽  
Optimization Method ◽  
Frame Structure ◽  
Manufacturing Cost ◽  
Detailed Design ◽  
High Manufacturing Cost ◽  
The Military ◽  
Rotary Wing ◽  
Novel Design

Rotary-wing unmanned aerial vehicles (UAVs) are widespread in both the military and civilian applications. However, there are still some problems for the UAV design such as the long design period, high manufacturing cost, and difficulty in maintenance. Therefore, this paper proposes a novel design method to obtain a lightweight and maintainable UAV frame from configurable design to detailed design. First, configurable design is implemented to determine the initial design domain of the UAV frame. Second, topology optimization method based on inertia relief theory is used to transform the initial geometric model into the UAV frame structure. Third, process design is considered to improve the manufacturability and maintainability of the UAV frame. Finally, dynamic drop test is used to validate the crashworthiness of the UAV frame. Therefore, a lightweight UAV frame structure composed of thin-walled parts can be obtained and the design period can be greatly reduced via the proposed method.

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