Flow simulation of the flight manoeuvres of a large transport aircraft with load alleviation

2021 ◽  
pp. 1-29
Author(s):  
C. Breitenstein ◽  
R. Radespiel
Keyword(s):  
Three Dimensional ◽  
Flow Simulation ◽  
Bending Moment ◽  
New Method ◽  
Control Surface ◽  
Navier Stokes ◽  
Secondary Effects ◽  
Transport Aircraft ◽  
Surface Deflections ◽  
Rigid Wing

Abstract A new method for predicting manoeuvre loads on a large transport aircraft with a swept-back wing and a load alleviation system based on control surface deflections is developed. For this purpose, three-dimensional Reynolds-averaged Navier–Stokes (RANS) simulations of the rigid wing–fuselage configuration are performed while the aerodynamics of the tailplane are estimated by means of handbook methods. For a closer analysis, different quasi-steady pitching manoeuvres are chosen based on the CS-25 regulations. One of these manoeuvres is also simulated with active load alleviation, leading to a reduction in the wing-root bending moment by more than 40%. Besides demonstrating the potential of the considered load alleviation system, it is shown which manoeuvres are especially critical in this context and which secondary effects come along with load alleviation.

Turbulent Flow Simulation of a Runner for Francis Hydraulic Turbines Using Pseudo-Compressibility

1996 ◽  
Vol 118 (2) ◽  
pp. 285-291 ◽  
Author(s):  
Chuichi Arakawa ◽  
Yi Qian ◽  
Takashi Kubota
Keyword(s):  
Compressible Flows ◽  
Incompressible Flows ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Leading Edge ◽  
Design Tool ◽  
Design Flow ◽  
Navier Stokes ◽  
Small Computer ◽  
Strong Vortex

A three-dimensional Navier-Stokes code with pseudo-compressibility, an implicit formulation of finite difference, and a k – ε two-equation turbulence model has been developed for the Francis hydraulic runner. The viscous flow in the rotating field can be simulated well in the design flow operating condition as well as in the off-design conditions in which a strong vortex occurs due to the separation near the leading edge. Because the code employs an implicit algorithm and a wall function near the wall, it does not require a large CPU time. It can therefore be used on a small computer such as the desk-top workstation, and is available for use as a design tool. The same kind of algorithm that is used for compressible flows has been found to be appropriate for the simulation of complex incompressible flows in the field of turbomachinery.

Analysis of Complex Three-Dimensional Flow in a Three-Stage LP Turbine by Means of Transitional Navier-Stokes Simulation

2000 ◽  
Author(s):  
Jochen Gier ◽  
Sabine Ardey ◽  
Adam Heisler
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Navier Stokes ◽  
Flow Visualisation ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Lp Turbine ◽  
Extensive Experimental Data ◽  
Highly Loaded

The complex three-dimensional flow field in a highly loaded three-stage LPT is analysed on the basis of a steady three-dimensional flow simulation. The quality of the simulation concerning this configuration is demonstrated by means of a comparison with extensive experimental data gathered in a turbine test rig. For an accurate representation of the transitional character of the turbine flow a modified version of the Abu-Ghannam Shaw transition model is employed in the TRACE_S Navier-Stokes code in connection with a two-equation turbulence model. The flow field of this highly loaded turbine is characterised by complex secondary flow pattern as well as local separation and reattachment zones. The need and applicability of transition modelling is demonstrated by a comparison with a fully turbulent calculation and experimental flow visualisation. The basic flow structure is described in terms of several characteristic quantities and discussed in detail. For further analysis variations of the point of operation and the geometry also based on experiments are included in this investigation.

A Three Dimensional Spiral Casing Navier-Stokes Flow Simulation

1996 ◽  
pp. 81-90
Author(s):  
Ch. Bruttin ◽  
J.-L. Kueny ◽  
B. Boyer ◽  
K. Héon ◽  
T. C. Vu ◽  
...  
Keyword(s):  
Stokes Flow ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Navier Stokes ◽  
Spiral Casing

The Modeling and Flow Simulation of 40BZ6-15 Centrifugal Pump

2011 ◽  
Vol 317-319 ◽  
pp. 789-793
Author(s):  
Xiao Feng Shang ◽  
Liang Tong ◽  
Zhi Jian Wang
Keyword(s):  
Velocity Field ◽  
Centrifugal Pump ◽  
Pressure Field ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Internal Flow ◽  
Navier Stokes ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Navier Stokes Equation

The three-Dimensional model of 40BZ6-15 centrifugal pump is built by the Solidworks software. This paper employs three-D Navier-Stokes equation and standard equation, and uses MRF and STMPLE algorithm to simulate the internal flowing of the 40BZ6 centrifugal pump. The velocity field and pressure field are gained. Through a further analysis, the rule of the internal flow of the centrifugal pump is unveiled, and then the simulative results are compared with the experimental ones, which can provide the base for the further improvement of the centrifugal pump.

scholarly journals Direct Numerical Simulation of Gas–Particle Flows with Particle–Wall Collisions Using the Immersed Boundary Method

2018 ◽  
Vol 8 (12) ◽  
pp. 2387 ◽  
Author(s):  
Yusuke Mizuno ◽  
Shun Takahashi ◽  
Kota Fukuda ◽  
Shigeru Obayashi
Keyword(s):  
Immersed Boundary Method ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Navier Stokes ◽  
Immersed Boundary ◽  
Navier Stokes Equation ◽  
Level Set Function ◽  
Boundary Method ◽  
The One ◽  
Energy And Momentum

We investigated particulate flows by coupling simulations of the three-dimensional incompressible Navier–Stokes equation with the immersed boundary method (IBM). The results obtained from the two-way coupled simulation were compared with those of the one-way simulation, which is generally applied for clarifying the particle kinematics in industry. In the present flow simulation, the IBM was solved using a ghost–cell approach and the particles and walls were defined by a level set function. Using proposed algorithms, particle–particle and particle–wall collisions were implemented simply; the subsequent coupling simulations were conducted stably. Additionally, the wake structures of the moving, colliding and rebounding particles were comprehensively compared with previous numerical and experimental results. In simulations of 50, 100, 200 and 500 particles, particle–wall collisions were more frequent in the one–way scheme than in the two-way scheme. This difference was linked to differences in losses in energy and momentum.

Drag and Cavity Development of Two Slender Bodies: A Numerical Study

2015 ◽  
Author(s):  
Yong-Du Jun ◽  
Kang-Sik Bae ◽  
Seok-Soon Lee ◽  
Jong Soo Lee
Keyword(s):  
Drag Coefficient ◽  
Stokes Equations ◽  
Numerical Study ◽  
Phase Interface ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Navier Stokes ◽  
Slender Bodies ◽  
Cavity Development ◽  
Disk Cavitator

In the present study, an unsteady three-dimensional flow simulation based on the RANS (Reynolds Average Navier-Stokes) equations with k-ε turbulence model and Singhal et al.’s cavitation model is conducted to study the cavity development behavior of two slender bodies, that is, a flat-headed cylinder and a step-headed cylinder of 50 mm in length and 10 mm in diameter. Using so called VOF method to track the liquid-vapor phase interface, time dependent solutions with varying approach speed range from 10 m/s to 55 m/s are obtained and analyzed to provide key information such as cavity initiation speed, drag coefficient and the cavity shape and size (max. length and diameter). The implemented numerical model is validated for flows over a flat disk cavitator against the experimental correlation. According to the present simulation results, slender bodies with two different head shapes, that is, a flat cylinder and a stepped one, respectively, showed very close behavior in their cavity initiation speed, maximum developed cavity diameter and length, but consistently lower drag coefficient with the step-headed cylinder case, which suggests the possible advantage of seeking optimized cavitator shape.

scholarly journals Numerical Flow Simulation in a Centrifugal Pump at Design and Off-Design Conditions

2007 ◽  
Vol 2007 ◽  
pp. 1-8 ◽  
Author(s):  
K. W. Cheah ◽  
T. S. Lee ◽  
S. H. Winoto ◽  
Z. M. Zhao
Keyword(s):  
Centrifugal Pump ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Internal Flow ◽  
Leading Edge ◽  
Design Flow ◽  
Vortical Flow ◽  
Navier Stokes ◽  
Pump Impeller ◽  
Rate Condition

The current investigation is aimed to simulate the complex internal flow in a centrifugal pump impeller with six twisted blades by using a three-dimensional Navier-Stokes code with a standardk-εtwo-equation turbulence model. Different flow rates were specified at inlet boundary to predict the characteristics of the pump. A detailed analysis of the results at design load,Qdesign, and off-design conditions, Q = 0.43Qdesignand Q = 1.45Qdesign, is presented. From the numerical simulation, it shows that the impeller passage flow at design point is quite smooth and follows the curvature of the blade. However, flow separation is observed at the leading edge due to nontangential inflow condition. The flow pattern changed significantly inside the volute as well, with double vortical flow structures formed at cutwater and slowly evolved into a single vortical structure at the volute diffuser. For the pressure distribution, the pressure increases gradually along streamwise direction in the impeller passages. When the centrifugal pump is operating under off-design flow rate condition, unsteady flow developed in the impeller passage and the volute casing.

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