scholarly journals Comparison of Aerodynamic Characteristics of NACA 0012 and NACA 2412 Airfoil

2021 ◽  
Vol 9 (VII) ◽  
pp. 2037-2045
Author(s):  
S. M Mehady Hasan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Experimental Methods ◽  
Aerodynamic Characteristics ◽  
Steady State Flow ◽  
Pressure Contour ◽  
Computational Fluid Dynamics Cfd ◽  
Velocity Contour ◽  
Naca 0012

A comparison between NACA 0012 and NACA 2412 has been made by comparing the lift co- efficient, drag co-efficient, pressure contour and velocity contour at various angles of attack. The process has been done taking steady state flow around NACA-0012 and NACA-2412 airfoil using 1m chord length and a velocity of 88.65m/s. The main aim is to understand the aerodynamic characteristics of both the airfoils at different angles of attack and draw a conclusion on which performs better under the same conditions. Modelling and numerical analysis has been carried out by using commercially available CFD software, which is a convenient method of analysis since computational methods are more preferred to experimental methods due to low expenses involved. The numerical results demonstrated are compatible with those of the theory. This confirms the validity of using Computational Fluid Dynamics (CFD) as a reliable alternative to experimental procedures.

CFD Leakage Predictions of Unworn and Worn Labyrinth Seals With and Without Tooth Axial Offset

2017 ◽  
Author(s):  
Hasham H. Chougule ◽  
Alexander Mirzamoghadam
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Modeling ◽  
Steady State ◽  
Flow Field ◽  
Labyrinth Seals ◽  
Small Clearance ◽  
Total Leakage ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Deflection

The objective of this study is to develop a Computational Fluid Dynamics (CFD) based methodology for analyzing and predicting leakage of worn or rub-intended labyrinth seals during operation. The simulations include intended tooth axial offset and numerical modeling of the flow field. The purpose is to predict total leakage through the seal when an axial tooth offset is provided after the intended/unintended rub. Results indicate that as expected, the leakage for the in-line worn land case (i.e. tooth under rub) is higher compared to unworn. Furthermore, the intended rotor/teeth forward axial offset/shift with respect to the rubbed land reduces the seal leakage. The overall leakage of a rubbed seal with axial tooth offset is observed to be considerably reduced, and it can become even less than a small clearance seal designed not to rub. The reduced leakage during steady state is due to a targeted smaller running gap because of tooth offset under the intended/worn land groove shape, higher blockages, higher turbulence and flow deflection as compared to worn seal model without axial tooth offset.

Numerical Prediction of Blended Wing Body Aerodynamic Characteristics at Subsonic Speed

2014 ◽  
Vol 71 (2) ◽  
Author(s):  
Pang Jung Hoe ◽  
Nik Ahmad Ridhwan Nik Mohd
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Performance ◽  
Aerodynamic Characteristic ◽  
Aerodynamic Characteristics ◽  
Numerical Prediction ◽  
Navier Stokes ◽  
Subsonic Speed ◽  
Computational Fluid Dynamics Cfd ◽  
Blended Wing Body

The need for high performance and green aircraft has brought the blended wing (BWB) aircraft concept to the centre of interest for many researchers. BWB is a type of aircraft characterized by a complex blending geometry between fuselage and wing. Recently, many researches had been performed to unlock its aerodynamic complexity that is still not well understood. In this paper, aerodynamic characteristic of a baseline BWB configuration derived from simple conventional aircraft configuration was analysed using the Reynolds-averaged Navier-Stokes computational fluid dynamics (CFD) solver. The main objectives of this work are to predict the aerodynamic characteristics of the BWB concept at steady flight conditions and at various pitch angles. The results obtained are then compared against a simple conventional aircraft configuration (CAC). The results show that the BWB configuration used has 24% higher L/D ratio than the CAC. The increment to the L/D however is mainly due to lower drag than the improvement in the lift. 

In-Cylinder Flow Correlations Between Steady Flow Bench and Motored Engine Using Computational Fluid Dynamics

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Xiaofeng Yang ◽  
Tang-Wei Kuo ◽  
Orgun Guralp ◽  
Ronald O. Grover ◽  
Paul Najt
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Velocity Profile ◽  
Discharge Coefficient ◽  
Intake Port ◽  
Charge Motion ◽  
Steady State Flow ◽  
Cfd Simulations ◽  
Motored Engine

Intake port flow performance plays a substantial role in determining the volumetric efficiency and in-cylinder charge motion of a spark-ignited engine. Steady-state flow bench and motored engine flow computational fluid dynamics (CFD) simulations were carried out to bridge these two approaches for the evaluation of port flow and charge motion (such as discharge coefficient, swirl/tumble ratios (SR/TR)). The intake port polar velocity profile and polar physical clearance profile were generated to evaluate the port performance based on local flow velocity and physical clearance in the valve-seat region. The measured data were taken from standard steady-state flow bench tests of an intake port for validation of CFD simulations. It was reconfirmed that the predicted discharge coefficients and swirl/tumble index (SI/TI) of steady flow bench simulations have a good correlation with those of motored engine flow simulations. Polar velocity profile is strongly affected by polar physical clearance profile. The polar velocity inhomogeneity factor (IHF) correlates well with the port discharge coefficient, swirl/tumble index. Useful information can be extracted from local polar physical clearance and velocity, which can help for intake port design.

Three-Dimensional CFD Analysis of Gas Mixing in Large Volumes

2001 ◽  
Author(s):  
Brian L. Smith
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Three Dimensional ◽  
Air Injection ◽  
Cfd Analysis ◽  
Gas Mixing ◽  
Air Mixing ◽  
Computational Fluid Dynamics Cfd ◽  
Pure Steam

Abstract The paper describes three-dimensional Computational Fluid Dynamics (CFD) calculations undertaken in support of analyses of steam/air mixing which takes place in the drywell volumes of the 1/40th-scale ESBWR1 mock-up facility PANDA under conditions of symmetric steam/air injection and asymmetric outflow. Steady-state simulations for pure steam conditions illustrate how the flow streams mix to ensure balanced outflow conditions to the condensers. A transient calculation has also been performed to examine how air released from solution in the PANDA boiler would ultimately accumulate in the separate condenser units. Results provide a possible explanation for the rundown in performance of one of the condensers which was repeatedly observed in some of the PANDA tests.

Achieving high parallel performance for an unstructured unsteady turbomachinery CFD code

2007 ◽  
Vol 111 (1117) ◽  
pp. 185-193 ◽  
Author(s):  
N. Hills
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Load Balancing ◽  
Unstructured Mesh ◽  
Test Cases ◽  
Hexahedral Mesh ◽  
Parallel Performance ◽  
Computational Fluid Dynamics Cfd ◽  
Work Done

This paper describes the work done to achieve high parallel performance for an unstructured, unsteady turbomachinery computational fluid dynamics (CFD) code. The aim of the work described here is to be able to scale problems to the thousands of processors that current and future machine architectures will provide. The CFD code is in design use in industry and is also used as a research tool at a number of universities. High parallel scalability has been achieved for a range of turbomachinery test cases, from steady-state hexahedral mesh cases to fully unsteady unstructured mesh cases. This has been achieved by a combination of code modification and consideration of the parallel partitioning strategy and resulting load balancing. A sliding plane option is necessary to run fully unsteady multistage turbomachinery test cases and this has been implemented within the CFD code. Sample CFD calculations of a full turbine including parts of the internal air system are presented.

scholarly journals Computational Fluid Dynamics Study of Swimmer's Hand Velocity, Orientation, and Shape: Contributions to Hydrodynamics

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Milda Bilinauskaite ◽  
Vishveshwar Rajendra Mantha ◽  
Abel Ilah Rouboa ◽  
Pranas Ziliukas ◽  
Antonio Jose Silva
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Flow ◽  
Steady State ◽  
Drag Force ◽  
3D Models ◽  
Hydrodynamic Characteristics ◽  
Front Crawl ◽  
Drag Forces ◽  
Computational Fluid Dynamics Cfd

The aim of this paper is to determine the hydrodynamic characteristics of swimmer’s scanned hand models for various combinations of both the angle of attack and the sweepback angle and shape and velocity of swimmer's hand, simulating separate underwater arm stroke phases of freestyle (front crawl) swimming. Four realistic 3D models of swimmer's hand corresponding to different combinations of separated/closed fingers positions were used to simulate different underwater front crawl phases. The fluid flow was simulated using FLUENT (ANSYS, PA, USA). Drag force and drag coefficient were calculated using (computational fluid dynamics) CFD in steady state. Results showed that the drag force and coefficient varied at the different flow velocities on all shapes of the hand and variation was observed for different hand positions corresponding to different stroke phases. The models of the hand with thumb adducted and abducted generated the highest drag forces and drag coefficients. The current study suggests that the realistic variation of both the orientation angles influenced higher values of drag, lift, and resultant coefficients and forces. To augment resultant force, which affects swimmer's propulsion, the swimmer should concentrate in effectively optimising achievable hand areas during crucial propulsive phases.

A New Method of Strengthening Longitudinal Static Stability of Airship in Ascent

2014 ◽  
Vol 687-691 ◽  
pp. 212-215
Author(s):  
Hou Di Xiao ◽  
Pan Pan Mi ◽  
Long Bin Liu ◽  
Shuai Cao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Aerodynamic Characteristics ◽  
Static Stability ◽  
New Method ◽  
Aerodynamic Shape ◽  
Computational Fluid Dynamics Cfd ◽  
Static Instability ◽  
Longitudinal Static Stability ◽  
Aerodynamic Lift

To improve the controllability and maneuverability, airship is usually designed as static instability. But the airship is vulnerable to sudden wind interference in its ascent, resulting in divergent pitching motion. A new aerodynamic shape was put forward which added a inflatable aerodynamic-lift wing at backward of the airship hull. With the method of Computational Fluid Dynamics (CFD), aerodynamic characteristics and longitudinal static stability of the conventional airship and new winged airship were comparative investigated. It can be concluded that the new winged airship was longitudinal stable whereas the conventional airship was instable. It can be applied for restraining the sudden wind interference for airship in ascent.

Theoretical Deduction and Experimental Visualization of Streamlines in Mixed-Flow Impeller

2015 ◽  
Vol 719-720 ◽  
pp. 279-283
Author(s):  
Kun Xi Qian ◽  
Teng Jing
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Logarithmic Spiral ◽  
Pressure Head ◽  
Experimental Methods ◽  
Mixed Flow ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Cfd

Streamlines in mixed-flow impeller were deduced by solving partial differential equations of continuity, motion and energy; they could be simplified to be logarithmic spiral and parabola in vertical and horizontal sections respectively. Then a mixed-flow impeller was designed and manufactured, its vane had a logarithmic spiral and its shroud had a parabola form. Computational fluid dynamics (CFD) demonstrated that the streamlines in the impeller were coincided with the vane and shroud; particle image velocimetry (PIV) exhibited also that the streamlines in vane channel were really logarithmic spiral at the designing point of pumping flow rate and pressure head. It concludes that both theoretical and experimental methods presented in this paper are informative and convincing, and thus are worthy to be investigated further.

Effects of Design Parameters for Clay Brick Kiln Using Computational Fluid Dynamics and Experimental Design

2015 ◽  
Vol 1101 ◽  
pp. 51-56 ◽  
Author(s):  
W. Ratanathavorn ◽  
S. Charoenjai ◽  
S. Janbuala ◽  
B. Chalermsinsuwan ◽  
K. Poochinda
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Three Dimensional ◽  
Design Parameters ◽  
Clay Brick ◽  
Brick Kiln ◽  
Industrial Setting ◽  
Steady State Temperature ◽  
Computational Fluid Dynamics Cfd

One of the most critical steps in brick making is firing, performed to harden the bricks. In a typical non-industrial setting, many pieces of extruded clays are stacked into a box-shaped kiln with equally-spaced rectangular vertical holes and another set of equally-spaced horizontal holes at the bottom across two sides. Roman roof tiles are used to cover the vertical sides, while leaving the horizontal holes opened, to complete the kiln assembly. Rice husk is filled in the holes of the kiln and is used as the fuel for firing. However, approximately 10% of the bricks, stacked conventionally, are always not appropriately fired. Therefore, this research aimed at simplifying model and redesigning the clay brick kiln using three-dimensional computational fluid dynamics (CFD). The studied parameters for 23 factorial designs were as follows: kiln height (200 – 225 cm), horizontal holes width (7.5 – 15 cm) and height (45 – 60 cm). The total volume of brick stack, averaged steady-state temperature and time to reach a steady-state temperature were selected as the response parameters. The analysis of variance (ANOVA) of 23 factorial design showed that the width and height of holes affected the time to reach steady-state but the averaged steady-state temperature and the total volume of brick stack were dependent on all 3 parameters. Then, a kiln was constructed according to the model with the maximum number of bricks and only 4% of the bricks were not appropriately fired.

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