scholarly journals Nozzle Geometry Effects on Corner Boundary Layers in Supersonic Wind Tunnels

AIAA Journal ◽  
2019 ◽  
Vol 57 (8) ◽  
pp. 3620-3623 ◽  
Author(s):  
Kshitij Sabnis ◽  
Holger Babinsky
Keyword(s):  
Boundary Layers ◽  
Wind Tunnels ◽  
Nozzle Geometry ◽  
Geometry Effects

scholarly journals Nozzle Geometry-Induced Vortices in Supersonic Wind Tunnels

AIAA Journal ◽  
2020 ◽  
pp. 1-12
Author(s):  
Kshitij Sabnis ◽  
Holger Babinsky ◽  
Daniel S. Galbraith ◽  
John A. Benek
Keyword(s):  
Wind Tunnels ◽  
Nozzle Geometry

Decreasing the Side Wall Contamination in Wind Tunnels

1983 ◽  
Vol 105 (4) ◽  
pp. 435-438 ◽  
Author(s):  
T. Motohashi ◽  
R. F. Blackwelder
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Boundary Layers ◽  
Laminar Boundary Layer ◽  
Three Dimensional ◽  
Side Wall ◽  
Wind Tunnels ◽  
Turbulent Fluid ◽  
Side Walls ◽  
Suction Slot

To study boundary layers in the transitional Reynolds number regime, the useful spanwise and streamwise extent of wind tunnels is often limited by turbulent fluid emanating from the side walls. Some or all of the turbulent fluid can be removed by sucking fluid out at the corners, as suggested by Amini [1]. It is shown that by optimizing the suction slot width, the side wall contamination can be dramatically decreased without a concomitant three-dimensional distortion of the laminar boundary layer.

Boundary Layer and Loss Measurements on the Rotor of an Axial-Flow Turbine

1984 ◽  
Vol 106 (2) ◽  
pp. 391-399 ◽  
Author(s):  
H. P. Hodson
Keyword(s):  
Boundary Layers ◽  
Large Scale ◽  
Axial Flow ◽  
Turbine Rotor ◽  
Wind Tunnels ◽  
Shear Stresses ◽  
Surface Shear ◽  
Laminar Boundary Layers ◽  
Rotor Stator Interaction ◽  
Profile Loss

The aerodynamic efficiency of an axial-flow turbine is significantly less than that predicted by measurements made on equivalent cascades which operate with steady inflow. This difference in efficiencies is strongly dependent upon the rotor-stator axial spacing. An experimental investigation of the rotor-stator interaction has therefore been conducted using a large-scale, low-speed turbine. The blade profile loss and surface shear stresses are presented for the midspan of the rotor and for a rectilinear cascade of identical geometry. Both wind tunnels were operated at a Reynolds number of 3.15 × 105. The turbine rotor midspan profile loss was approximately 50 percent higher than that of the rectilinear cascade. The shear stress measurements indicate that as a stator wake is connected through a rotor passage, the laminar boundary layers undergo transition in the vicinity of the wake. The 50 percent increase in loss is due to the time-dependent transitional nature of the boundary layers.

Nozzle Effects in Thermal Wind Tunnels

2010 ◽  
Author(s):  
Zhu Wang ◽  
Jaehoon Han ◽  
Ales Alajbegovic
Keyword(s):  
Wind Tunnel ◽  
Lattice Boltzmann ◽  
Heat Exchangers ◽  
Wind Tunnels ◽  
Nozzle Geometry ◽  
Vehicle Design ◽  
Passenger Vehicle ◽  
Flow Solver ◽  
Thermal Wind ◽  
Good Agreement

Presented is an investigation of the wind-tunnel nozzle effects on the thermal performance within passenger vehicle underhood area. The Lattice-Boltzmann Equation (LBE) based flow solver is coupled with the system tool to solve for airflow and temperature distribution around the passenger vehicle in the wind tunnel. Several simulations with different nozzle sizes were performed. The simulation results are compared with airflow, temperature, and heat exchangers heat rejection measurements in the thermal wind tunnel. Good agreement is observed confirming that nozzle geometry dominates the airflow around the vehicle. The results show that different nozzle sizes can produce flows that have almost the same macroscopic characteristics while at the same time have subtle differences that can be very important for the vehicle design.

scholarly journals Eulerian CFD modeling of nozzle geometry effects on ECN Sprays A and D: assessment and analysis

2019 ◽  
Vol 21 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Adrian Pandal ◽  
Jose M Garcia-Oliver ◽  
Jose M Pastor
Keyword(s):  
Turbulence Modeling ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Computational Effort ◽  
Diffuse Interface ◽  
Cfd Modeling ◽  
Nozzle Geometry ◽  
Nozzle Flow ◽  
X Ray ◽  
Geometry Effects

Diesel spray modeling is a multi-scale problem with complex interactions between different flow regions, that is, internal nozzle flow, near-nozzle region and developed spray, including evaporation and combustion. There are several modeling approaches that have proven particularly useful for some spray regions although they have struggled at other areas, while Eulerian modeling has shown promise in dealing with all characteristics at a reasonable computational effort for engineering calculations. In this work, the [Formula: see text]–Y single-fluid diffuse-interface model, based on scale separation assumptions at high Reynolds and Weber numbers, is used to simulate the engine combustion network Sprays A and D within a Reynolds-averaged Navier–Stokes turbulence modeling approach. The study is divided into two parts. First of all, the larger diameter Spray D is modeled from the nozzle flow till evaporative spray conditions, obtaining successful prediction of numerous spray metrics, paying special attention to the near-nozzle region where spray dispersion and interfacial surface area can be validated against measurements conducted at the Advanced Photon Source at Argonne National Laboratory, including both the ultra-small-angle X-ray scattering and the X-ray radiography. Afterwards, an analysis of the modeling predictions is made in comparison with previous results obtained for Spray A, considering the nozzle geometry effects in the modeling behavior.

scholarly journals The Influence of Nozzle Geometry on Corner Flows in Supersonic Wind Tunnels

2019 ◽  
Author(s):  
Kshitij Sabnis ◽  
Daniel Galbraith ◽  
Holger Babinsky ◽  
John A. Benek
Keyword(s):  
Wind Tunnels ◽  
Nozzle Geometry ◽  
Corner Flows
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