Loss Mechanisms and Optimum Design Methodology for Efficient mm-Waves Class-E PAs

Flanged and flued type expansion joint (thick wall expansion bellow) used as an integral part of many shell and tube heat exchanger where process conditions produce differential expansion between shell and tubes. It provides flexibility for thermal expansion and also functions as a pressure retaining part. Design of expansion joints is usually based on trial and error method in which initial geometry must be assumed, and accordingly maximum stresses and spring rate are be calculated. Inadequate selection of geometry leads to higher tubesheet and bellow thickness, which increases cost of equipment. This paper presents standardization and optimum design approach of flange and flued expansion bellow fulfilling ASME VIII-1 and TEMA standard requirement. Methodology to define expansion bellow geometry is developed, and geometry dimensions are tabulated for expansion bellow diameter from 300 to 2000 mm and thickness from 6 to 30 mm. Each defined geometry is analyzed using finite element method, and maximum von Mises stresses are calculated for bellow axial displacement from 0.5 to 1.5 mm and internal pressure from 0.1 to 6.5 MPa. Spring rate is also calculated for each defined geometry for consideration in tubesheet calculation. Accordingly, optimum design methodology is developed, tested, and compared with existing design. Results depicted that proposed standardization approach and design methodology will optimize expansion bellow and tubesheet thickness and will also save considerable time in finalization of heat exchanger design.

Download Full-text

An Optimum Design Methodology for Planar-Type Coaxial Probes Applicable to Broad Temperature Permittivity Measurements

IEEE Transactions on Microwave Theory and Techniques ◽

10.1109/tmtt.2008.916986 ◽

2008 ◽

Vol 56 (3) ◽

pp. 684-692 ◽

Cited By ~ 11

Author(s):

Namgon Kim ◽

Jeonghoon Yoon ◽

Sungjoon Cho ◽

Jeiwon Cho ◽

Changyul Cheon ◽

...

Keyword(s):

Optimum Design ◽

Design Methodology ◽

Coaxial Probes ◽

Permittivity Measurements

Download Full-text

RELIABILITY BASED DESIGN OF RUBBLE-MOUND BREAKWATER

Coastal Engineering Proceedings ◽

10.9753/icce.v21.153 ◽

1988 ◽

Vol 1 (21) ◽

pp. 153

Author(s):

Masato Yamamoto ◽

Kazumasa Mizumura ◽

Taiji Endo ◽

Naofumi Shiraishi

Keyword(s):

Water Level ◽

Optimum Design ◽

Failure Probability ◽

Design Methodology ◽

Construction Cost ◽

Probabilistic Design ◽

Reliability Based Design ◽

Rubble Mound ◽

Reduced Risk

The object of this present research is to study probabilistic design of armor blocks protecting composite breakwaters and to produce optimum design methodology for S-shaped breakwaters in terms of failure probability and construction cost. Failure probability in the vicinity of the still water level is greatest in the case of uniform sloped breakwaters. Therefore,S-shaped breakwaters of which the slope near the still water level is milder have a reduced risk of damage compared to uniform sloped ones. The optimum design index presents good economics and reliability in rubble-mound breakwater design.

Download Full-text

Damped Vibration Absorbers Applied to Lateral Modes of Rotating Machinery

Volume 7A: 17th Biennial Conference on Mechanical Vibration and Noise ◽

10.1115/detc99/vib-8292 ◽

1999 ◽

Author(s):

Lyn M. Greenhill ◽

Linda F. Raven

Keyword(s):

Detailed Analysis ◽

Optimum Design ◽

Test Data ◽

Design Methodology ◽

Rotating Machinery ◽

Vibration Absorbers ◽

Mass Ratio ◽

Rotating Machine ◽

Lateral Modes ◽

Tuning Frequency

Abstract Damped vibration absorbers can significantly reduce the amplitude of resonant motion. Normally, these devices are used on machinery that is non-rotating (stationary). However, as this paper demonstrates both analytically and experimentally, a damped absorber can be successfully applied on rotating equipment, particularly on vertical machines, to attenuate lateral resonances. To illustrate this application, a detailed analysis of the damped absorber is presented, focusing on mass ratio, tuning frequency, amount of damping, and speed effects. It is shown that an optimum design can be obtained for use on a rotating machine that parametrically differs from a non-rotating application. Test data is also given illustrating the effectiveness of the concept and design methodology on an actual machine. Recommendations are provided to guide the application of this technology on other rotating machines.

Download Full-text

Optimum design methodology for thermally stable multi-finger power SiGe HBTs

2010 International Workshop on Junction Technology Extended Abstracts ◽

10.1109/iwjt.2010.5474901 ◽

2010 ◽

Author(s):

D. Y. Jin ◽

W. R. Zhang ◽

B. L. Guan ◽

L. Chen ◽

N. Hu ◽

...

Keyword(s):

Optimum Design ◽

Design Methodology ◽

Thermally Stable

Download Full-text

A Combinatory Design Methodology Dedicated to the Ball and Roller Screw Drives for Optimum Design

ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, Volume 4 ◽

10.1115/esda2010-24222 ◽

2010 ◽

Author(s):

Pierre Dupont

Keyword(s):

Optimum Design ◽

Design Methodology ◽

Short Review ◽

Optimization Techniques ◽

Industrial Case Study ◽

Endurance Strength ◽

Memorial Symposium ◽

Roller Screw ◽

The One ◽

User Friendly

Machine-tools, packaging units, lifting systems and also other heavy duty devices (f.e. used in steel casting technologies) employ advantageously screw drives (balls, re-circulating rollers, and planetary roller drives) as mechanical command elements (f.e. directly coupled to servo drives), especially for their high efficiencies (∼87 .. 98%) and “output force to input torque ratio”. After a short review of the most important checks (for Static and Endurance Strength, Life, Shocks resistance and also some Miscellaneous Effects due f.e. to Critical Speeds and Stress Concentrators) it will be described briefly a combinatory design methodology or “heuristics” which takes into account as the technical viability and reliability as well as the economical feasibility of the whole system line (included end bearings and transmission) leading to an “overall safety ratio matrix” and/or to “viability and reliability graphs” helping in such a way the designer to reach an “optimum design” by an overall helicopter view of his/her design(s). In terms of optimization techniques, this user friendly combinatory design methodology could be placed in the field of the “heuristic” ones. An industrial case study will illustrate that presentation. This presentation is also a continuation of the one given for the MS&T’09 occurring in PITTSBURGH, USA during the “Charles R. MORIN Memorial Symposium on Failure Analysis & Prevention” for the ASM International.

Download Full-text