scholarly journals Multi-mode adaptive-pitch propeller and its application prospects for ships with variable running conditions

2021 ◽  
Vol 4 (398) ◽  
pp. 53-60
Author(s):  
Leonid Vishnevsky ◽  

Object and purpose of research. This paper describes multi-mode adaptive-pitch propeller and its hydrodynamics. Based on the calculation data, the study demonstrates that this kind of propeller might be quite promising in terms of propulsion performance for the ships with variable running conditions, like patrol vessels that switch between patrol and chase running mode. More-over, multi-mode adaptive pitch propellers may work as two-positional CPPs commonly regarded as general-use propellers. These results might be useful in design of ships for various applications. Materials and methods. Experimental data on hydrodynamic parameters of multi-mode adaptive pitch propeller and design calculation results for a virtual triple-shaft patrol vessel. Main results. The results of this study could be useful in propeller selection for given ship design. Conclusion. It is shown that, as compared to FPPs, multi-mode adaptive pitch propellers are more efficient in terms of propulsion performance.

2020 ◽  
pp. 56-58
Author(s):  
P.V. Gubarev ◽  
D.V. Glazunov ◽  
V.G. Ruban ◽  
A.S. Shapshal

The thermal calculation of the locomotive traction engine collector is proposed. The equations of the heat balance of its elements are obtained taking into account the cooling air. The calculation results and experimental data of thermal imaging control are presented. Keywords: traction electric motor, collector, thermal calculation, thermal imaging control. [email protected]


2013 ◽  
Vol 671-674 ◽  
pp. 1761-1765
Author(s):  
Yong Liu ◽  
Chun Ming Song ◽  
Song Lin Yue

In order to get mechanical properties ,some RPC samples with 5% steel fiber are tested, many groups data were obtained such as compressive strength, shear strength and fracture toughness. And a group of tests on RPC with 5% steel-fiber under penetration were also conducted to validate the performance to impact. The penetration tests are carried out by the semi-AP projectiles with the diameter of 57 mm and earth penetrators with the diameter of 80 mm, and velocities of the two kinds of projectiles are 300~600 m/s and 800~900 m/s, respectively. By contrast between the experimental data and the calculation results of C30 reinforced concrete by using experiential formula under penetration, it shows that the resistance of steel-fiber RPC to penetration is 3 times as that of general C30 reinforced concrete.


Author(s):  
Alden Yellowhorse ◽  
Larry L. Howell

Ensuring that deployable mechanisms are sufficiently rigid is a major challenge due to their large size relative to their mass. This paper examines three basic types of stiffener that can be applied to light, origami-inspired structures to manage their stiffness. These stiffeners are modeled analytically to enable prediction and optimization of their behavior. The results obtained from this analysis are compared to results from a finite-element analysis and experimental data. After verifying these models, the advantages and disadvantages of each stiffener type are considered. This comparison will facilitate stiffener selection for future engineering applications.


2018 ◽  
Vol 197 ◽  
pp. 09005
Author(s):  
Bregas Siswahjono Tatag Sembodo ◽  
Hary Sulistyo ◽  
Wahyudi Budi Sediawan ◽  
Mohammad Fahrurrozi

Corncobs are potentially processed into bio-oil through thermochemical liquefaction processes. It is difficult to construct kinetics models based on the compounds involved in the reaction. It would be made four kinetic models based on four reaction products, i.e., solids, bio-oil, gas and volatile products. The purposes of the study were to seek kinetics model of thermochemical liquefaction of corncobs in ethanol-water solution and to study the effect of ethanol concentration. The experiment of liquefaction processes of corncobs in ethanol-water solution using sodium carbonate catalyst was performed in the 150 ml autoclave equipped with a magnetic stirrer in the temperature up to 280°C. Four kinetic models were applied to predict the yield of four reaction product lumps. The calculation results were compared to the experimental data. Compared to the others, model 4 was the most realistic and closely matching to the experimental data. In model 4 the reaction mechanism was assumed that biomass (corncobs) first decomposed into bio-oil, followed by decomposition of bio-oil into volatile products reversibly and, finally, volatile products decomposed into gaseous products. The yield of bio-oil increased from 42.05% to 54.93% by increasing to ethanol concentration of 0% to 40%.


2019 ◽  
pp. 88-93
Author(s):  
O.R. Trofymenko ◽  
А.V. Nosovsky ◽  
V.I. Gulik

Modeling of the neutron-physical characteristics of the Kyoto University KUCA subcritical facility was conducted using the Monte Carlo Serpent code. The effective multiplication factors for the critical experiments of the series II on the KUCA research subcritical facility were calculated. The presented calculation results were compared with the experimental results and the results of the calculations made using the Monte Carlo codes MCNP6 and KENO-VI.


2020 ◽  
pp. 5-11
Author(s):  
Vladimir Kurteyev ◽  
◽  
Boris Mozerov ◽  

There is studied the problems experiment modeling under impact of torn vane with turbojet fan case. There are outlined shortcomings of equipment for plane and cylindrical model cases testing. There is indicated the difference between calculation results and experimental data for metals plane models. There are indicated diagram laboratory experiment installation on basic pressurized balloons for testing metals plane models. There are calculated parameters of metals plane model with the point of views criterion modeling.


Author(s):  
V. I. Pegov ◽  
◽  
I. Yu. Moshkin ◽  

Numerical simulation of the underwater motion of flight vehicles launched from underwater is performed. The updated method of plane sections is used to determine the hydrodynamic parameters of flight vehicles under multiphase flow. Hydrodynamic loading can be evaluated through the determination of nonstationary boundaries of a gas cavity and the linear load on the water-flown aft. By the method of plane sections, the 3D boundary value problem of the cavitational flow of a flight vehicle at an attack angle resolves itself into a plane hydrodynamic problem, separate for each section of the cavity. The predicted results are compared with the experimental data. Validation and verification were performed by comparing the analysis results with the experimental data. The applicability of the method of plane sections to the determination of the hydrodynamic parameters of flight vehicles under multiphase flow is demonstrated.


1999 ◽  
Vol 17 (2) ◽  
pp. 293-298
Author(s):  
A.V. BESSARAB ◽  
S.A. BEL'KOV ◽  
P.D. GASPARYAN ◽  
N.V. ZHIDKOV ◽  
A.V. KUNIN ◽  
...  

Measurements of spectral and energy X-ray characteristics of almost transparent Fe plasma produced by laser radiation inside the inverted-corona targets have been made at ISKRA-5 facility. The targets were spherical plastics cavities with 2-mm diameter and 4.6-μm thickness covered from inside with Fe layer 0.25-μm thickness. X-ray spectrum, X-ray total energy, and the energy of a HeαFe resonance line have been measured. Experimental data and calculation results are collated.


2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Hailong Cui ◽  
Huan Xia ◽  
Dajiang Lei ◽  
Xinjiang Zhang ◽  
Zhengyi Jiang

In this paper, a calculation method based on matlab partial differential equations (PDE) tool is proposed to investigate the static characteristics of aerostatic spherical bearings. The Reynolds equation of aerostatic spherical bearings is transformed into a standard elliptic equation. The effects of geometric parameters and operational conditions on the film pressure, bearing film force, and stiffness are studied. The axial and radial eccentricities result in different film pressure distributions; the bearing film force and stiffness are significantly influenced by geometric parameters and operational conditions. The relative optimal parameters are confirmed based on the calculation results. A comparison between the numerical and experimental results is also presented. The highest relative error between the numerical results and the experimental data is 11.3%; the calculation results show good agreements with the experimental data, thus verifying the accuracy of the calculation method used in this paper.


Akustika ◽  
2021 ◽  
pp. 100-106
Author(s):  
sergey Timushev ◽  
Alexey Yakovlev ◽  
Petr Moshkov

The problem of simulation the noise generated during the operation of the propeller is considered. Calculation methods are described and numerical simulation of the noise of a light aircraft propeller by the acoustic-vortex method is performed. The results of numerical modeling of the tonal components of the propeller noise when operating under static conditions are compared with experimental data and calculation results based on a semiempirical model.


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