The Research on Post Rolling of Aerodynamic Characteristics Numerical Simulation of Flow Field

2014 ◽  
Vol 684 ◽  
pp. 30-33
Author(s):  
Qi Wang ◽  
Jing Zhang ◽  
Ming Ming ◽  
Xiao Xu Chen
Keyword(s):  
Flow Field ◽  
Preliminary Analysis ◽  
Aerodynamic Force ◽  
Aerodynamic Characteristics ◽  
Source Model ◽  
Cfd Analysis ◽  
Analysis Method ◽  
Model Flow ◽  
The Difference ◽  
Aerodynamic Torque

In this paper, according on post rolling maneuver and the flow field, we build a CFD analysis method about momentum source model flow field and aerodynamic characteristics. Preliminary analysis of the numerical has be finished to contrast the difference of post rolling maneuver. The changing law of aerodynamic force, aerodynamic torque variation and the focus position have be given.

Effects of Ice Thickness on the Aerodynamic Characteristics of Crescent Shape Iced Conductors

2012 ◽  
Vol 166-169 ◽  
pp. 2696-2703 ◽  
Author(s):  
Dong Yan ◽  
Wen Juan Lou ◽  
Ming Feng Huang ◽  
Wei Lin
Keyword(s):  
Lift Force ◽  
Aerodynamic Force ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Ice Thickness ◽  
Force Curve ◽  
Force Coefficients ◽  
Variation Patterns ◽  
The Difference ◽  
Force Characteristics

Aerodynamic characteristics of iced conductors were investigated by the wind tunnel test. Under the homogeneous turbulence of 5% intensity, aerodynamic force coefficients of single and bundled conductors were obtained at wind angles of 0°~180°. The variation patterns of aerodynamic forces on the iced conductors with respect to wind angels of attack were systematically studied for the ice thickness of 0.25, 0.5, 0.75 and 1 times of the conductor diameter. The difference of aerodynamic force characteristics for single and bundled conductors were identified and discussed. Based on the Den Hartog and Nigol’s mechanisms of galloping, the wind angle ranges sensitive to galloping were analyzed. The results show that lift and torsion force coefficients reach peak values at wind angles of 15°~20°. For bundled conductors, lift force curve is approximately agreed with the curve of single conductor. Drag force coefficients were smaller than these of single conductor at some wind angles. There are noticeably differences of torsion coefficients existed between bundled conductors and single conductor. According to two classical galloping mechanisms, wind angles of 15°~30°are critical for the galloping of iced conductors with crescent shapes.

Aerodynamic Simulation of Road Vehicle in Steady Crosswind

2013 ◽  
Vol 376 ◽  
pp. 341-344
Author(s):  
Shan Ling Han ◽  
Ru Xing Yu ◽  
Yu Yue Wang ◽  
Gui Shen Wang
Keyword(s):  
Flow Field ◽  
Wind Direction ◽  
Motor Vehicle ◽  
Aerodynamic Force ◽  
Flow Characteristics ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
External Flow ◽  
Slant Angle ◽  
Ahmed Body

Because crosswind affects drivers to control their vehicles safely, the research on flow characteristics in automotive crosswind has a great significance to improve the crosswind stability of the vehicle. By the steady state numerical simulation method, the aerodynamic characteristics of external flow field of Ahmed body in crosswind was investigated. The Ahmed body with 25° slant angle is built in UG NX. The external flow field of the Ahmed body in the wind direction of 0°, 15º, 30° angle is simulated in XFlow software. According to the map of the pressure and velocity distribution, the flow field both before and after, as well as left and right has significant change as the wind direction angle increased, and the trail turbulence intensity also changes. The changes of aerodynamic force and moment affect the driving stability of a motor vehicle.

scholarly journals Numerical method for an assessment of steady and motion-excited flowfields in a transonic cascade wind tunnel

2017 ◽  
Vol 1 ◽  
pp. QL9XVI ◽  
Author(s):  
Atsushi Tateishi ◽  
Toshinori Watanabe ◽  
Takehiro Himeno ◽  
Seiji Uzawa
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Numerical Method ◽  
Aerodynamic Characteristics ◽  
Pressure Amplitude ◽  
Tunnel Wall ◽  
Flow Simulations ◽  
Influence Coefficients ◽  
The Difference ◽  
Transonic Cascade

AbstractThis article presents a numerical method and its application for an assessment of the flow field inside a wind tunnel. A structured computational fluid dynamics (CFDs) solver with overset mesh technique is developed in order to simulate geometrically complex configurations. Applying the developed solver, a whole transonic cascade wind tunnel is modeled and simulated by a two-dimensional manner. The upstream and downstream periodicity of the cascade and the effect of the tunnel wall on the unsteady flow field are focused on. From the steady flow simulations, the existence of an optimum throttle position for the best periodicity for each tailboard angle is shown, which provides appropriate aerodynamic characteristics of ideal cascades in the wind tunnel environment. Unsteady simulations with blade oscillation is also conducted, and the difference in the influence coefficients between ideal and wind tunnel configurations becomes large when the pressure amplitude increases on the lower blades.

scholarly journals Motion Analysis of Butterfly-Style Flapping Robot Using CFD Based on 3D-CAD Model and Experimental Flight Data

2021 ◽  
Vol 33 (2) ◽  
pp. 216-222
Author(s):  
Keisuke Sanuki ◽  
◽  
Taro Fujikawa
Keyword(s):  
Flow Field ◽  
Motion Analysis ◽  
The Body ◽  
Cad Model ◽  
Cfd Analysis ◽  
Flight Data ◽  
3D Cad ◽  
Pitch Moment ◽  
The Difference ◽  
Analysis System

In this paper, a computational fluid dynamics (CFD) analysis system based on a 3D-CAD model of a butterfly-style flapping robot using its experimental flight data is proposed. The butterfly-style flapping robot can control its attitude by changing its flapping and lead-lag angles; however, measuring the lift, thrust, and body pitch moment directly during flight is difficult. In the case of the flight motion analysis of insects, the state of flight has been photographed, and numerical analysis has been performed to obtain the flow field around the wings. However, when performing the motion analysis of hardware, it is difficult to reflect the shape of the body accurately using this method. In this study, a CFD analysis system considered the shape of the developed butterfly-style flapping robot as 3D-CAD data and analyzed the flow field around the wings using the experimental flight data of the hardware. The results of motion analysis showed that the attitude during flight differs due to the difference in lifts and body pitch moments in the flight experiment data of the hardware with different neutral angles of the flapping wings.

Aerodynamics of a two-dimensional flapping wing hovering in proximity of ground

2019 ◽  
Vol 233 (12) ◽  
pp. 4316-4332 ◽  
Author(s):  
Yunlong Zheng ◽  
Qiulin Qu ◽  
Peiqing Liu ◽  
Yunpeng Qin ◽  
Ramesh K Agarwal
Keyword(s):  
Flow Field ◽  
Stokes Equations ◽  
Aerodynamic Force ◽  
Ground Effect ◽  
Flapping Wing ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Navier Stokes Equations ◽  
Lift Mechanism ◽  
The Difference

The difference in aerodynamic forces of a two-dimensional flapping wing hovering in unbounded flow field and ground effect is studied. The unsteady laminar Navier–Stokes equations are solved by the finite volume method to simulate the flow field around the wing. In the unbounded flow field, the correspondence between the aerodynamic force, pressure distribution on wing, and typical vortex structures is established, and then the high-lift mechanism of the flapping wing is further explained. In the ground effect, based on the lift variation, the dimensionless height H/ C ( H is the height of the wing above ground and C is the chord length of the wing) can be divided into transition and ground effect regimes. In the transition regime ( H/ C > 2.5), the lift decreases with the decreasing height, and the ground indirectly impacts the vortices near wing by changing the shed vortices in space. In the ground effect regime ( H/ C < 2.5), the lift increases with the decreasing height, and the ground directly impacts the vortices near the wing.

Implementasi Sistem Informasi Monitoring Pengolahan Data Inventory Gudang Pada PT.Talaga Mulya Indah

2020 ◽  
Vol 6 (2) ◽  
pp. 187-197
Author(s):  
Nurlaila Suci Rahayu Rais ◽  
Dedeh Apriyani ◽  
Gito Gardjito
Keyword(s):  
Data Processing ◽  
Integrated Control ◽  
Unified Modeling Language ◽  
Review Literature ◽  
Analysis Method ◽  
Inventory Data ◽  
Literature Study ◽  
Unified Modeling ◽  
The Difference ◽  
The Right

Monitoring of warehouse inventory data processing is an important thing for companies. PT Talaga mulya indah is still manual using paper media, causing problems that have an effect on existing information, namely: problems with data processing of incoming and outgoing goods. And the difference between data on the amount of stock of goods available with physical data, often occurs inputting data more than once for the same item, searching for available data, and making reports so that it impedes companies in monitoring inventory of existing stock of goods. Which aims to create a system that can provide updated information to facilitate the warehouse admin in making inventory reports, and reduce errors in input by means of integrated control. In this study, the authors used the data collection method used in this analysis using the method of observation, interviews, and literature review (literature study). For analysis using the PIECES analysis method. Furthermore, the system design used is UML (Unified Modeling Language). The results of this study are expected to produce the right data in the process of monitoring inventory data processing, also can provide the right information and make it easier to control the overall availability of goods.

Pandhawa Gubah sebagai Representasi Interaksi Metafisik Manusia Jawa dan Perbandingannya dengan Cheritera Pandawa Lima

Manuskripta ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Novarina Novarina
Keyword(s):  
Comparative Study ◽  
Literary Theory ◽  
Research Method ◽  
Descriptive Analysis ◽  
Literary Study ◽  
Analysis Method ◽  
Research Objects ◽  
Similarities And Differences ◽  
The Difference ◽  
The Comparative Study

Abstract: This research is a comparative literary study that uses Malay and Javanese versions of Mahabarata text sources. The research objects used were the text edition of Pandhawa Gubah (PG) by Sudibjo Z. Hadisutjipto and the text of Cheritera Pandawa Lima (CPL) by Khalid Hussain. The research method used is descriptive-analysis method. In the comparative study used a comparative literary theory proposed by Endraswara (2011). The results of the text comparison reveal the similarities and differences in the image of Bima figures in the Javanese and Malay versions. The equation as a whole is that both texts contain the same heroic storyline and heroic character, Bima. In addition, Indian influence is still evident in the two texts seen from the nuances of Hinduism that exist in both texts. While the difference is seen in the events that accompany Bima's struggle in achieving his victory. Based on these similarities and differences, it can be seen that the authors attempt to represent the concept of metaphysical interactions vertically and horizontally expressed through PG text. --- Abstrak: Penelitian ini adalah satu kajian sastra bandingan yang menggunakan sumber teks Mahabarata versi Melayu dan Jawa. Objek penelitian yang digunakan adalah edisi teks Pandhawa Gubah (PG) karya Sudibjo Z. Hadisutjipto dan teks Cheritera Pandawa Lima (CPL) karya Khalid Hussain. Metode penelitian yang digunakan adalah metode deskriptif-analisis. Dalam telaah perbandingan digunakan teori sastra bandingan yang dikemukakan Endraswara (2011). Hasil perbandingan teks mengungkapkan adanya persamaan dan perbedaan citra tokoh Bima dalam versi Jawa maupun versi Melayu. Persamaan secara keseluruhan adalah kedua teks tersebut mengandung alur cerita kepahlawanan dan tokoh pahlawan yang sama yaitu Bima. Selain itu, pengaruh India masih tampak dalam kedua teks tersebut dilihat dari nuansa Hinduisme yang ada dalam kedua teks. Sementara perbedaannya tampak pada peristiwa-peristiwa yang menyertai perjuangan Bima dalam mencapai kemenangannya. Berdasarkan persamaan dan perbedaan tersebut tampak adanya upaya penulis untuk merepresentasikan konsep interaksi metafisik secara vertikal dan horizontal yang diungkapkan melalui teks PG.

Kesalahan Penggunaan Bahasa Perancis dalam Tulisan Mahasiswa Program Studi Sastra Perancis Unpad

Metahumaniora ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 368
Author(s):  
Gilang Januarsyah
Keyword(s):  
General Public ◽  
Qualitative Approach ◽  
French Language ◽  
Analysis Method ◽  
Writing Skill ◽  
Language Writing ◽  
The Difference ◽  
Observation Method ◽  
Bahasa Indonesia

ABSTRAKUntuk menghasilkan sebuah karangan berbahasa Perancis yang dapat dipahamioleh khalayak umum, mahasiswa harus menguasai kemampuan berbahasa Perancis ragamtulis yang baik dan benar sesuai dengan kaidah yang berlaku. Penelitian ini bertujuanuntuk menjelaskan kesalahan sintaksis yang dilakukan oleh mahasiswa Program StudiSastra Perancis Universitas Padjadjaran. Data yang digunakan dalam penelitian ini diambildari sepuluh karangan mahasiwa yang duduk di semester lima dan tujuh dan dianalisisdengan menggunakan metode simak dan metode analisis padan referensial translasionaldengan pendekatan kualitatif. Hasil dari penelitian ini menunjukkan bahwa kesalahantertinggi yang dilakukan mahasiswa adalah kesalahan dalam penggunaan passé composédan imparfait sebesar 50%, kemudian diikuti oleh kesalahan dalam penggunaan pronomrelatif simple et composé ‘pronomina penghubung bebas dan turunan’ sebesar 30%, danterakhir kesalahan dalam penggunaan pronom COD et COI ‘pronomina COD dan COI’ sebesar20%. Faktor yang menyebabkan terjadinya kesalahan tersebut adalah faktor linguistikyang disebabkan oleh perbedaan kaidah tatabahasa bahasa Indonesia dan Perancis.Selain itu terdapat pula faktor sosiolinguistik yang disebabkan oleh jarangnya mahasiswamembiasakan diri mereka untuk mengaplikasikan bahasa Perancis di luar kelas.Kata kunci: kesalahan, sintaksis, bahasa Perancis, tulis, pengajaranABST RACTTo produce a French-language essay that can be understood by the general public,the students should master the ability of French language in good and true writing skill inaccordance with the applicable rules. The aim of this research is to explain the syntactic errorsmade by students of French literature’s program at University Padjadjaran. The sources ofdata are taken from the ten student essays who sit in the fifth and seventh semesters, and themethods used in this research are Observation Method ‘Metode Simak’ and the analyticalreference translational analysis method with a qualitative approach. The results of thisresearch indicate that the highest errors that students make are the use of passé composéand imparfait as much as fifty percent, followed by errors in the use of pronom relatifsimple et composé ‘the free and derivative pronouns’ thirty percent, and the last error is inthe use of pronom CO D et CO I ‘‘The COD and COI pronouns’ twenty percent. The factors thatcause those errors are a linguistic caused by the difference rules of Indonesian and Frenchgrammar. In addition there are also sociolinguistic factors caused by the rarity of studentsfamiliarize themselves to apply the French language outside the classroom.Keywords: Error, syntax, French language, writing, teaching

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