Study of Complex Three-dimensional Hypersonic Shock Interactions for Future Re-usable Space Transport Systems

2003 ◽  
Author(s):  
Yukimitsu Yamamoto
Keyword(s):  
Three Dimensional ◽  
Transport Systems ◽  
Shock Interactions ◽  
Hypersonic Shock

scholarly journals Investigations of Three-Dimensional Shock/Shock Interactions over Symmetrical Intersecting Wedges

AIAA Journal ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 1472-1481 ◽  
Author(s):  
G. X. Xiang ◽  
C. Wang ◽  
H. H. Teng ◽  
Z. L. Jiang
Keyword(s):  
Three Dimensional ◽  
Shock Interactions

Effects of Downstream Vane Bowing and Asymmetry on Unsteadiness in a Transonic Turbine

2018 ◽  
Author(s):  
John P. Clark ◽  
Richard J. Anthony ◽  
Michael K. Ooten ◽  
John M. Finnegan ◽  
P. Dean Johnson ◽  
...  
Keyword(s):  
Turbine Blades ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Time Resolved ◽  
Turbine Engine ◽  
Shock Interactions ◽  
Design Changes ◽  
Post Test ◽  
Measured Time ◽  
Transonic Turbine

Accurate predictions of unsteady forcing on turbine blades are essential for the avoidance of high-cycle-fatigue issues during turbine engine development. Further, if one can demonstrate that predictions of unsteady interaction in a turbine are accurate, then it becomes possible to anticipate resonant-stress problems and mitigate them through aerodynamic design changes during the development cycle. A successful reduction in unsteady forcing for a transonic turbine with significant shock interactions due to downstream components is presented here. A pair of methods to reduce the unsteadiness was considered and rigorously analyzed using a three-dimensional, time resolved Reynolds-Averaged Navier Stokes (RANS) solver. The first method relied on the physics of shock reflections itself and involved altering the stacking of downstream components to achieve a bowed airfoil. The second method considered was circumferentially-asymmetric vane spacing which is well known to spread the unsteadiness due to vane-blade interaction over a range of frequencies. Both methods of forcing reduction were analyzed separately and predicted to reduce unsteady pressures on the blade as intended. Then, both design changes were implemented together in a transonic turbine experiment and successfully shown to manipulate the blade unsteadiness in keeping with the design-level predictions. This demonstration was accomplished through comparisons of measured time-resolved pressures on the turbine blade to others obtained in a baseline experiment that included neither asymmetric spacing nor bowing of the downstream vane. The measured data were further compared to rigorous post-test simulations of the complete turbine annulus including a bowed downstream vane of non-uniform pitch.

scholarly journals Biodynamics of supine humans and interaction with transport systems during vibration and shocks

2017 ◽  
Vol 38 (2) ◽  
pp. 808-816 ◽  
Author(s):  
Salam Rahmatalla ◽  
Jonathan DeShaw ◽  
Khalid Barazanji
Keyword(s):  
Relative Motion ◽  
Random Vibration ◽  
Whole Body Vibration ◽  
Three Dimensional ◽  
Whole Body ◽  
Transport Systems ◽  
Biomechanical Response ◽  
Contact Surfaces ◽  
Vertical Accelerations ◽  
Human Transport

This work investigates the effect of the contact surfaces on the biomechanical response of supine humans during whole-body vibration and shocks. Twelve participants were exposed to three-dimensional random vibration and shocks and were tested with two types of contact surfaces: (i) litter only, and (ii) litter with spinal board. The two configurations were tested with and without body straps to secure the supine human. The addition of the spinal board reduced the involuntary motion of the supine humans in most directions. There were significant reductions in the relative vertical accelerations at the neck and torso areas, especially during shocks ( p < 0.01). The inclusion of body straps with the spinal board was more effective in reducing the relative motion in most directions when shocks were presented. This study shows that the ergonomic design of the human transport system and the underlying contacting surfaces should be studied during dynamic transport environments.

scholarly journals An Unstructured Shock-Fitting Technique For Three-Dimensional Flows With Shock Interactions

2021 ◽  
Author(s):  
C. Ollivier-Gooch ◽  
R. Paciorri ◽  
A. Assonitis ◽  
A. Bonfiglioli
Keyword(s):  
Three Dimensional ◽  
Shock Interactions ◽  
Shock Fitting

scholarly journals Simulation-Based Design of Urban Bi-modal Transport Systems

2020 ◽  
Vol 1 ◽  
Author(s):  
Gabriel Tilg ◽  
Zain Ul Abedin ◽  
Sasan Amini ◽  
Fritz Busch
Keyword(s):  
Transport System ◽  
Three Dimensional ◽  
Optimization Techniques ◽  
Transport Systems ◽  
Fundamental Diagram ◽  
Urban Networks ◽  
Strategic Design ◽  
Macroscopic Fundamental Diagram ◽  
Simulation Based ◽  
Road Space

The three-dimensional passenger macroscopic fundamental diagram (pMFD) describes the relation of the network accumulation of public transport and private vehicles, and the passenger production. It allows for modeling the multi-modal traffic dynamics in urban networks and deriving innovative performance indicators. This paper integrates this concept into a multi-modal transport system design framework formulated as a simulation-based optimization problem. In doing so, we consider the competition for limited road space and the operational characteristics, such as congestion occurrences, at the strategic design level. We evaluate the proposed framework in a case study for the Sioux Falls network. Thereby, we deliver a proof of concept, and show that the proposed methodology indeed designs a transport system which benefits the overall system's performance. This paper further advances the integration of sequential model-based optimization techniques, macroscopic traffic flow concepts, and traffic simulation to design multi-modal transport systems. This supports transport planners and local authorities in composing efficient and robust transport networks.

Numerical Investigation of Wake-Shock Interactions and Clocking in a Transonic HP Turbine

2003 ◽  
Author(s):  
Michele Marconcini ◽  
Roberto Pacciani
Keyword(s):  
Shock Waves ◽  
Gas Turbine ◽  
Three Dimensional ◽  
Frame Of Reference ◽  
Heavy Duty ◽  
Blade Loading ◽  
Shock Interactions ◽  
Blade Row ◽  
Wake Passing ◽  
Stators And Rotors

A quasi-three-dimensional, blade-to-blade, time-accurate, viscous solver was used for the clocking optimization of a modern transonic heavy-duty, two stage gas turbine. Both stators and rotors operate in a transonic regime with fish-tail shock systems at the blade row exit. These shock systems interact with both stator and rotor wakes. A sensible reduction in the strength of shock waves was observed due to the upstream blade row wake passing. Such wake-shock interactions occur in the inter-blade gap, around locations which are fixed in the frame of reference of the downstream blade-row. The exploitation of such an effect to optimize the axial/circumferential position of blade rows is still compatible with the axial gap values commonly used for these kinds of stages. The results of the clocking investigation will be presented and discussed in terms of unsteady blade loading and efficiency variations.

Three-dimensional shock interactions and vortices on a V-shaped blunt leading edge

2019 ◽  
Vol 31 (8) ◽  
pp. 086102 ◽  
Author(s):  
Enlai Zhang ◽  
Zhufei Li ◽  
Yiming Li ◽  
Jiming Yang
Keyword(s):  
Three Dimensional ◽  
Leading Edge ◽  
Shock Interactions ◽  
Blunt Leading Edge
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