scholarly journals OPTIMASI GAYA ANGKAT HOVERCRAFT TIPE INTEGRATED DENGAN PERUBAHAN KONFIGURASI AXIAL FAN

Author(s):  
Widhi Herjuna
Keyword(s):  

Hovercraft memiliki beberapa kelebihan dibandingkan alat transportasi lainnya. Pada saat bergerak hovercraft berada diatas bantalan udara, maka hambatan yang dialami oleh hovercraft menjadi sangat kecil. Hal ini membuat hovercraft dapat beroperasi pada segala macam permukaan, tidak hanya rendahnya hambatan yang dialami terhadap bentuk medan kerjanya dan permukaan air, tetapi kemampuan ampibi yang unik yang membuat hovercraft dapat beroperasi pada macam-macam permukaan yang berbeda secara kontinu termasuk mencapai daerah pedalaman tanpa mengalami kendala akibat dangkalnya permukaan air sungai atau bebatuan yang banyak terdapat pada sungai-sungai Indonesia. Simulasi pada penelitian ini dilakukan dibantu dengan menggunakan perangkat lunak  NumecaFineTM atau perangkat lunak Turbo V8. Penelitian ini menghasilkan beberapa kesimpulan yang dapat digunakan sebagai rekomendasi untuk penelitian berikutnya. Tidak memerlukan thrust yang tinggi karena yang diunggulkan ialah kemampuan hover yang stabil. Dengan data perhitungan thrust 831,8 N, lift 4900 rpm, 5 buah blade, ratio 2,1 :1 , dan angle blade 300. Korelasi thrust dan lift berbanding lurus dengan bahan bakar yang dihasilkan. Target nominal gaya angkat yang didapat ialah 15 cm tercapai dengan analisa perhitungan yang dilakukan.

2020 ◽  
Vol 36 (2) ◽  
pp. 75-85
Author(s):  
R.Z. Aкhunov ◽  

The article presents the modernization of the design of the universal seed mordant PSS-20 by installing an axial fan and air ducts for closed air circulation in the processing chamber, which will ensure the full use of the mordant, work safety and increase the productivity of cultivated crops. The main advantage of this design is that the seeds in the same plane as the suspension flow is affected by the air flow, which improves the penetration into the layer. Air ducts make it possible to reuse the suspension that has not settled on the seeds. This is achieved due to the closed lid design. During operation, the fan creates excessive pressure inside the seed stream and rarefaction outside, and so small drops of solution that have penetrated the seed stream are sucked in by the fan and re-fed into the stream.


2018 ◽  
Vol 140 (7) ◽  
Author(s):  
J. J. Defoe ◽  
M. Etemadi ◽  
D. K. Hall

Applications such as boundary-layer-ingesting (BLI) fans and compressors in turboprop engines require continuous operation with distorted inflow. A low-speed axial fan with incompressible flow is studied in this paper. The objectives are to (1) identify the physical mechanisms which govern the fan response to inflow distortions and (2) determine how fan performance scales as the type and severity of inlet distortion varies at the design flow coefficient. A distributed source term approach to modeling the rotor and stator blade rows is used in numerical simulations in this paper. The model does not include viscous losses so that changes in diffusion factor are the primary focus. Distortions in stagnation pressure and temperature as well as swirl are considered. The key findings are that unless sharp pitchwise gradients in the diffusion response, strong radial flows, or very large distortion magnitudes are present, the response of the blade rows for strong distortions can be predicted by scaling up the response to a weaker distortion. In addition, the response to distortions which are composed of nonuniformities in several inlet quantities can be predicted by summing up the responses to the constituent distortions.


2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Aurélie Ortolan ◽  
Suk-Kee Courty-Audren ◽  
Nicolas Binder ◽  
Xavier Carbonneau ◽  
Yannick Bousquet ◽  
...  

A steady mixing plane approach is compared with the time-averaged solution of an unsteady full annulus calculation for a conventional fan operating at load-controlled windmill. The objective is to assess the added value of a complete unsteady calculation compared with a more classical approach, especially concerning the effect of the spatial and temporal periodicity release in such an unusual operation as windmill. Experiment with global steady measurements and rotor radial characterizations was conducted. Numerical analysis demonstrates that windmilling global performances obtained with the time-averaged solution of the unsteady simulation are not far different from the steady case, especially in the rotor. Some differences arise in the stator, particularly regarding the velocity field. Temporal periodicity release in this row has clearly a significant effect on the flow unsteady response. A detailed analysis highlights that generic patterns of windmilling flows recorded on a steady approach are also reported on the unsteady case.


2011 ◽  
Author(s):  
Takeshi Murooka ◽  
Shinichirou Shishido ◽  
Riho Hiramoto ◽  
Takakazu Minoya
Keyword(s):  

2012 ◽  
Vol 16 (suppl. 2) ◽  
pp. 593-603 ◽  
Author(s):  
Zivan Spasic ◽  
Sasa Milanovic ◽  
Vanja Sustersic ◽  
Boban Nikolic

The paper presents the design and operating characteristics of a model of reversible axial fan with only one impeller, whose reversibility is achieved by changing the direction of rotation. The fan is designed for the purpose of providing alternating air circulation in wood dryers in order to reduce the consumption of electricity for the fan and increase energy efficiency of the entire dryer. To satisfy the reversibility of flow, the shape of the blade profile is symmetrical along the longitudinal and transversal axes of the profile. The fan is designed with equal specific work of all elementary stages, using the method of lift forces. The impeller blades have straight mean line profiles. The shape of the blade profile was adopted after the numerical simulations were carried out and high efficiency was achieved. Based on the calculation and conducted numerical simulations, a physical model of the fan was created and tested on a standard test rig, with air loading at the suction side of the fan. The operating characteristics are shown for different blade angles. The obtained maximum efficiency was around 0.65, which represents a rather high value for axial fans with straight profile blades.


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