A Design Method on Propeller Current Meters

1978 ◽  
Vol 100 (1) ◽  
pp. 83-90
Author(s):  
Rikiya Takeda
Keyword(s):  
Wind Tunnel ◽  
Rational Design ◽  
Design Method ◽  
Water Tunnel ◽  
Characteristic Equations ◽  
Wide Range ◽  
Basic Equations ◽  
Fundamental Equations

A rational design method on propeller current meters that has a wide range of application to various fluids such as air, water, and oil is described. First, the runner characteristics were analyzed using the previously derived basic equations [6]. Next, many sorts of runners were tested in streams, such as the water tunnel, the oil tunnel, the wind tunnel, and the lowing tank. From these results, a general meter calibration formula, which is applicable to various fluids, was derived. If we use the basic equations, the characteristic equations and this calibration formula as the fundamental equations of the meter design, we can design current meter runners applicable to various fluids.

scholarly journals Nano-imprinted subwavelength gratings as polarizing beamsplitters

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Julian Wüster ◽  
Yannick Bourgin ◽  
Patrick Feßer ◽  
Arne Behrens ◽  
Stefan Sinzinger
Keyword(s):  
Nanoimprint Lithography ◽  
Optical Measurement ◽  
Design Method ◽  
Optical Systems ◽  
Surface Metrology ◽  
Measurement Systems ◽  
Common Path ◽  
Dielectric Coatings ◽  
Subwavelength Gratings ◽  
Wide Range

AbstractPolarizing beamsplitters have numerous applications in optical systems, such as systems for freeform surface metrology. They are classically manufactured from birefringent materials or with stacks of dielectric coatings. We present a binary subwavelength-structured form-birefringent diffraction grating, which acts as a polarizing beamsplitter for a wide range of incidence angles −30∘…+30∘. We refine the general design method for such hybrid gratings. We furthermore demonstrate the manufacturing steps with Soft-UV-Nanoimprint-Lithography, as well as the experimental verification, that the structure reliably acts as a polarizing beamsplitter. The experimental results show a contrast in efficiency for TE- and TM-polarization of up to 1:18 in the first order, and 34:1 in the zeroth order. The grating potentially enables us to realize integrated compact optical measurement systems, such as common-path interferometers.

scholarly journals Fluorescent thermal shift-based method for detection of NF-κB binding to double-stranded DNA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Peter D. Leitner ◽  
Ilja Vietor ◽  
Lukas A. Huber ◽  
Taras Valovka
Keyword(s):  
Dna Binding ◽  
Rational Design ◽  
Dissociation Constants ◽  
Inflammatory Diseases ◽  
Dimethyl Fumarate ◽  
Bioinformatic Analysis ◽  
Quantitative Detection ◽  
Regulatory Sequences ◽  
Wide Range ◽  
Inhibitory Drug

AbstractThe nuclear factor kappa B (NF-κB) family of dimeric transcription factors regulates a wide range of genes by binding to their specific DNA regulatory sequences. NF-κB is an important therapeutic target linked to a number of cancers as well as autoimmune and inflammatory diseases. Therefore, effective high-throughput methods for the detection of NF-κB DNA binding are essential for studying its transcriptional activity and for inhibitory drug screening. We describe here a novel fluorescence-based assay for quantitative detection of κB consensus double-stranded (ds) DNA binding by measuring the thermal stability of the NF-κB proteins. Specifically, DNA binding proficient NF-κB probes, consisting of the N-terminal p65/RelA (aa 1–306) and p50 (aa 1–367) regions, were designed using bioinformatic analysis of protein hydrophobicity, folding and sequence similarities. By measuring the SYPRO Orange fluorescence during thermal denaturation of the probes, we detected and quantified a shift in the melting temperatures (ΔTm) of p65/RelA and p50 produced by the dsDNA binding. The increase in Tm was proportional to the concentration of dsDNA with apparent dissociation constants (KD) of 2.228 × 10–6 M and 0.794 × 10–6 M, respectively. The use of withaferin A (WFA), dimethyl fumarate (DMF) and p-xyleneselenocyanate (p-XSC) verified the suitability of this assay for measuring dose-dependent antagonistic effects on DNA binding. In addition, the assay can be used to analyse the direct binding of inhibitors and their effects on structural stability of the protein probe. This may facilitate the identification and rational design of new drug candidates interfering with NF-κB functions.

Experiences with alluvial foundations for earth dams in the Prairie provinces

1979 ◽  
Vol 16 (2) ◽  
pp. 255-271 ◽  
Author(s):  
N. Peters ◽  
K. N. Lamb
Keyword(s):  
Rational Design ◽  
Preliminary Design ◽  
Empirical Relationships ◽  
Design Concepts ◽  
Theoretical Design ◽  
Pore Pressures ◽  
Wide Range ◽  
Thick Layers ◽  
Limited Testing ◽  
Prairie Provinces

The foundations for numerous dams in proglacial and interglacial valleys in the Prairie provinces consist of soft alluvial soils. The deposits are up to 60 m deep, and contain thick layers of clay interspersed with lenses and layers of silt, sand, and gravel.This paper describes the damsite investigation and laboratory testing required, the design methods and construction procedures used, and the foundation performance observed during and after construction. A number of empirical relationships between index tests and physical properties of the soils, which provide useful guidelines for preliminary design, are presented.The design approach has gradually evolved from an empirical design with limited testing to a more rational design based on detailed investigations and thorough instrumentation. Increased reliance is placed on observational apparatus to monitor movements and pore pressures to confirm design assumptions as construction proceeds. The theoretical design is always checked with former designs of dams that have performed satisfactorily.Safe economical dams have been constructed in spite of large deformations and high pore pressures. Two case histories illustrate the wide range in dam design for alluvial foundations. The first shows an older design cross section with modifications required to ensure a stable dam, and the second describes a recently constructed dam that incorporates many of the latest design concepts.

ECA Methodology for Fatigue Design of Risers and Flowlines

2007 ◽  
Author(s):  
C. H. Luk ◽  
T. J. Wang
Keyword(s):  
Fracture Mechanics ◽  
Design Method ◽  
Steel Catenary Riser ◽  
Fatigue Design ◽  
Wide Range ◽  
Fatigue And Fracture ◽  
Level 3 ◽  
Fatigue Loads ◽  
Vessel Motion ◽  
Level 2

Engineering Criticality Assessment (ECA) is a procedure based on fracture mechanics that may be used to supplement the traditional S-N approach and determine the flaw acceptance and inspection criteria in fatigue and fracture design of risers and flowlines. A number of design codes provide guidance for this procedure, e.g. BS-7910:2005 [1]. However, more investigations and example studies are still needed to address the design implications for riser and flowline applications. This paper provides a review of the existing ECA methodology, presents a fracture mechanics design method for a wide range of riser and flowline fatigue problems, and shows flaw size results from steel catenary riser (SCR) and flowline (FL) examples. The first example is a deepwater SCR subjected to fatigue loads due to vessel motion and riser VIV. The second example is a subsea flowline subjected to thermal fatigue loads. The effects of crack re-characterization and material plasticity on the Level-2 and Level-3 ECA results of the SCR and flowline examples are illustrated.

A Design Method for Thermosyphon Solar Domestic Hot Water Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 150-155 ◽  
Author(s):  
M. P. Malkin ◽  
S. A. Klein ◽  
J. A. Duffie ◽  
A. B. Copsey
Keyword(s):  
Flow Rate ◽  
Design Method ◽  
Water Systems ◽  
Hot Water ◽  
Average Flow Rate ◽  
Domestic Hot Water ◽  
Average Flow ◽  
Solar Fraction ◽  
Wide Range ◽  
Flow Circuit

A modification to the f-Chart method has been developed to predict monthly and annual performance of thermosyphon solar domestic hot water systems. Stratification in the storage tank is accounted for through use of a modified collector loss coefficient. The varying flow rate throughout the day and year in a thermosyphon system is accounted for through use of a fixed monthly “equivalent average” flow rate. The “equivalent average” flow rate is that which balances the thermosyphon buoyancy driving force with the frictional losses in the flow circuit on a monthly average basis. Comparison between the annual solar fraction predited by the modified design method and TRNSYS simulations for a wide range of thermosyphon systems shows an RMS error of 2.6 percent.

Instability in slotted wall tunnels

1958 ◽  
Vol 4 (3) ◽  
pp. 283-305 ◽  
Author(s):  
J. L. King ◽  
P. Boyle ◽  
J. B. Ogle
Keyword(s):  
Wind Tunnel ◽  
Experimental Evidence ◽  
Theoretical Explanation ◽  
Water Tunnel ◽  
Design Consideration ◽  
Working Section

A new water tunnel, incorporating a slotted wall working section, was found to suffer from severe vibration. A theoretical explanation is given for this, together with experimental evidence gleaned from this water tunnel and a small wind tunnel. It is shown that the oscillations are hydrodynamic in origin and are associated with the slotted wall design. Consideration is given to methods of elimination or reduction of the oscillations.

Multivariate design and analysis of aircraft HEX under multiple working conditions within flight envelope

2021 ◽  
pp. 1-18
Author(s):  
Qihang Liu ◽  
G.Q. Xu ◽  
Jie Wen ◽  
Yanchen Fu ◽  
Laihe Zhuang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Working Conditions ◽  
Design Method ◽  
Structural Parameters ◽  
Optimal Structure ◽  
Clear Correlation ◽  
Pressure Drops ◽  
Design Variables ◽  
Wide Range ◽  
Common Weight

Abstract This paper presents a multi-condition design method for the aircraft heat exchanger (HEX), marking with light weight, compactness and wide range of working conditions. The quasi-traversal genetic algorithm (QT-GA) method is introduced to obtain the optimal values of five structural parameters including the height, the tube diameter, the tube pitch, and the tube rows. The QT-GA method solves the deficiency of the conventional GA in the convergence, and gives a clear correlation between design variables and outputs. Pressure drops, heat transfer and the weight of the HEX are combined in a single objective function of GA in the HEX design, thus the optimal structure of the HEX suitable for all the working conditions can be directly obtained. After optimization, the weight of the HEX is reduced to 2.250 kg, more than 20% lower than a common weight of around 3 kg. Based on the optimal structure, the off-design performance of the HEX is further analyzed. Results show that the extreme working conditions for the heat transfer and the pressure drops are not consistent. It proves the advance of the multi-condition design method over traditional single-condition design method. In general, the proposed QT-GA design method is an efficient way to solve the multi-condition problems related to the aircraft HEX or other energy systems.

Automation and Management of Design Process of the Main Drive for an Innovative Fruits and Vegetables Washer

2021 ◽  
Vol 27 (1) ◽  
pp. 9-17
Author(s):  
V. P. Bui ◽  
◽  
S. S. Gavruishin ◽  
V. B. Phung ◽  
H. M. Dang ◽  
...  
Keyword(s):  
Design Process ◽  
Rational Design ◽  
Fruits And Vegetables ◽  
Rational Solution ◽  
Quality Criteria ◽  
Pareto Optimal ◽  
Optimal Domain ◽  
Wide Range ◽  
A New Technique ◽  
New Generation

A new technique is described, used by the authors to automate the design process of the main drive of a new generation machine intended for industrial washing of fruits and vegetables. To solve the problem of multi-criteria design, the original approach is proposed that uses interconnected mathematical models describing the dynamic behavior, strength reliability and functional characteristics of the machine in a unified information space. The generalized mathematical model includes 12 controlled parameters, 16 functional constraints, and 3 quality criteria. A genetic algorithm was used to find the space of Pareto-optimal solutions. The situational approach was used to select the final rational solution from a set of solutions belonging to the Pareto-optimal domain. The rational design of option the washer found using the proposed approach is compared with the existing ones. The proposed design methodology can be recommended for the design of a wide range of similar mechanical structures.

scholarly journals The Combined Effect of Rotation and Magnetic Field on Finite-Amplitude Thermal Convection

1973 ◽  
Vol 26 (5) ◽  
pp. 617 ◽  
Author(s):  
R Van der Borght ◽  
JO Murphy
Keyword(s):  
Magnetic Field ◽  
Mean Field ◽  
Field Approximation ◽  
Finite Amplitude ◽  
Combined Effect ◽  
Mean Field Approximation ◽  
Free Boundaries ◽  
Wide Range ◽  
The Mean ◽  
Basic Equations

The combined effect of an imposed rotation and magnetic field on convective transfer in a horizontal Boussinesq layer of fluid heated from below is studied in the mean field approximation. The basic equations are derived by a variational technique and their solutions are then found over a wide range of conditions, in the case of free boundaries, by numerical and analytic techniques, in particular by asymptotic and perturbation methods. The results obtained by the different techniques are shown to be in excellent agreement. As for the linear theory, the calculations predict that the simultaneous presence' of a magnetic field and rotation may produce conflicting tendencies.

An Experimental and Numerical Assessment of Airfoil Polars for Use in Darrieus Wind Turbines: Part 2 — Post-Stall Data Extrapolation Methods

2015 ◽  
Author(s):  
Alessandro Bianchini ◽  
Francesco Balduzzi ◽  
John M. Rainbird ◽  
Joaquim Peiro ◽  
J. Michael R. Graham ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbines ◽  
Full Range ◽  
Vertical Axis ◽  
Wind Tunnel Tests ◽  
Numerical Assessment ◽  
Wide Range ◽  
Naca0018 Airfoil ◽  
Lift And Drag ◽  
Data Extrapolation

Accurate post-stall airfoil data extending to a full range of incidences between −180° to +180° is important to the analysis of Darrieus vertical-axis wind turbines (VAWTs) since the blades experience a wide range of angles of attack, particularly at the low tip-speed ratios encountered during startup. Due to the scarcity of existing data extending much past stall, and the difficulties associated with obtaining post-stall data by experimental or numerical means, wide use is made of simple models of post-stall lift and drag coefficients in wind turbine modeling (through, for example, BEM codes). Most of these models assume post-stall performance to be virtually independent of profile shape. In this study, wind tunnel tests were carried out on a standard NACA0018 airfoil and a NACA 0018 conformally transformed to mimic the “virtual camber” effect imparted on a blade in a VAWT with a chord-to-radius ratio c/R of 0.25. Unsteady CFD results were taken for the same airfoils both at stationary angles of attack and at angles of attack resulting from a slow VAWT-like motion in an oncoming flow, the latter to better replicate the transient conditions experienced by VAWT blades. Excellent agreement was obtained between the wind tunnel tests and the CFD computations for both the symmetrical and cambered airfoils. Results for both airfoils also compare favorably to earlier studies of similar profiles. Finally, the suitability of different models for post-stall airfoil performance extrapolation, including those of Viterna-Corrigan, Montgomerie and Kirke, was analyzed and discussed.

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