Behavior of airfoil with control surface freeplay for nonzero angles of attack

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 651-653
Author(s):  
Denis B. Kholodar ◽  
Earl H. Dowell
Keyword(s):  
Control Surface

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

Nonlinear response of airfoil section with control surface freeplay to gust loads

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1543-1557 ◽  
Author(s):  
Deman Tang ◽  
Denis Kholodar ◽  
Earl H. Dowell
Keyword(s):  
Nonlinear Response ◽  
Control Surface ◽  
Airfoil Section ◽  
Gust Loads

scholarly journals Bone Marrow Mesenchymal Stromal Cells on Silk Fibroin Scaffolds to Attenuate Polymicrobial Sepsis Induced by Cecal Ligation and Puncture

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1433
Author(s):  
Ok-Hyeon Kim ◽  
Jun-Hyung Park ◽  
Jong-In Son ◽  
Ok-Ja Yoon ◽  
Hyun-Jung Lee
Keyword(s):  
Bone Marrow ◽  
Cecal Ligation ◽  
Biological Properties ◽  
Pge2 Production ◽  
Polymicrobial Sepsis ◽  
Control Surface ◽  
Related Factors ◽  
Cox 2 ◽  
Anti Inflammatory

Suitable scaffolds with appropriate mechanical and biological properties can improve mesenchymal stromal cell (MSC) therapy. Because silk fibroins (SFs) are biocompatible materials, they were electrospun and applied as scaffolds for MSC therapy. Consequently, interferon (IFN)-primed human bone marrow MSCs on SF nanofibers were administered into a polymicrobial sepsis murine model. The IL-6 level gradually decreased from 40 ng/mL at 6 h after sepsis to 35 ng/mL at 24 h after sepsis. The IL-6 level was significantly low as 5 ng/mL in primed MSCs on SF nanofibers, and 15 ng/mL in primed MSCs on the control surface. In contrast to the acute response, inflammation-related factors, including HO-1 and COX-2 in chronic liver tissue, were effectively inhibited by MSCs on both SF nanofibers and the control surface at the 5-day mark after sepsis. An in vitro study indicated that the anti-inflammatory function of MSCs on SF nanofibers was mediated through enhanced COX-2-PGE2 production, as indomethacin completely abrogated PGE2 production and decreased the survival rate of septic mice. Thus, SF nanofiber scaffolds potentiated the anti-inflammatory and immunomodulatory functions of MSCs, and were beneficial as a culture platform for the cell therapy of inflammatory disorders.

Time-Accurate Simulation of Longitudinal Flight Mechanics with Control by CFD/RBD Coupling

2012 ◽  
Vol 226-228 ◽  
pp. 788-792 ◽  
Author(s):  
Dong Guo ◽  
Min Xu ◽  
Shi Lu Chen
Keyword(s):  
Computational Study ◽  
Rigid Motion ◽  
Rigid Body Dynamics ◽  
Flight Mechanics ◽  
Control Surface ◽  
Free Flight ◽  
Body Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Coupled Solution ◽  
Surface Deflections

This paper describes a multidisciplinary computational study undertaken to compute the flight trajectories and simultaneously predict the unsteady free flight aerodynamics of aircraft in time domain using an advanced coupled computational fluid dynamics (CFD)/rigid body dynamics (RBD) technique. This incorporation of the flight mechanics equations and controller into the CFD solver loop and the treatment of the mesh, which must move with both the control surface deflections and the rigid motion of the aircraft, are illustrated. This work is a contribution to a wider effort towards the simulation of aeroelastic and flight stability in regions where nonlinear aerodynamics, and hence potentially CFD, can play a key role. Results demonstrating the coupled solution are presented.

scholarly journals Research on control effectiveness of fluidic thrust vectoring

2021 ◽  
Vol 104 (1) ◽  
pp. 003685042199813
Author(s):  
Fei Xue ◽  
Gu Yunsong ◽  
Yuchao Wang ◽  
Han Qin
Keyword(s):  
High Altitude ◽  
Ground State ◽  
Deflection Angle ◽  
Internal Flow ◽  
Lateral Force ◽  
Control Surface ◽  
Low Density ◽  
Thrust Vectoring ◽  
Density State ◽  
Fluidic Thrust Vectoring

In view of the control effects of fluidic thrust vector technology for low-speed aircraft at high altitude/low density and low altitude/high density are studied. The S-A model of FLUENT software is used to simulate the flow field inside and outside the nozzle with variable control surface parameters, and the relationship between the area of control surface and the deflection effect of main flow at different altitudes is obtained. It is found that the fluidic thrust vectoring nozzle can effectively control the internal flow in the ground state and the high altitude/low density state. and the mainstream deflection angle can be continuously adjusted. The maximum deflection angle of the flow in the ground state is 21.86°, and the maximum deviation angle of the 20 km high altitude/low density state is 18.80°. The deflecting of the inner flow of the nozzle is beneficial to provide more lateral force and lateral torque for the aircraft. The high altitude/low density state is taken as an example. When the internal flow deflects 18.80°, the lateral force is 0.32 times the main thrust. For aircraft with high altitude and low density, sufficient lateral and lateral torque can make the flying aircraft more flexible, which can make up the shortcomings of the conventional rudder failure and even replace the conventional rudder surface.

Hierarchical Self-Assembly of Microgel-Modified Biomaterials Surfaces

2014 ◽  
Vol 1622 ◽  
pp. 1-6
Author(s):  
Yong Wu ◽  
Jing Liang ◽  
Qichen Wang ◽  
Matthew Libera
Keyword(s):  
Self Assembly ◽  
Scale Effects ◽  
Control Surface ◽  
Poly Ethylene Glycol ◽  
Hydrogel Particles ◽  
Network Properties ◽  
Tissue Cells ◽  
Poly Ethylene ◽  
Non Line Of Sight

ABSTRACTMicrogels are hydrogel particles with micron and sub-micron diameters. They have beendeveloped, studied, and exploited for a broad range of applications because of their uniquecombination of size, soft mechanical properties, and controllable network properties. We havebeen using microgels to modulate the properties of surfaces to differentially control theirinteractions with tissue cells and bacteria. The long-term goal is to create biomaterials thatpromote healing while simultaneously inhibiting infection. Because poly(ethylene glycol) [PEG]is used in a number of FDA-approved products and has well-known antifouling properties, wework primarily with PEG-based microgels. We render these anionic either by copolymerizationwith monomeric acids or by blending with polyacids. Both methods produce pH-dependentnegative charge. Surfaces, both planar 2-D surfaces as well as topographically complex 3-Dsurfaces, can be modified using a hierarchy of non-line-of-sight electrostatic depositionprocesses that create biomaterials surfaces whose cell adhesiveness is modulated by a submonolayerof microgels. Average inter-microgel spacings of 1-2 microns exploit naturaldifferences between staphylococcal bacteria and tissue cells, which open the opportunity todifferentially control surface interactions with them based on length-scale effects. Afterdeposition, the microgels can be loaded with a variety of small-molecule, cationic antimicrobials.The details of loading depend on the relative sizes of the antimicrobials and the microgelnetwork structure as well as on the amount and spatial distribution of electrostatic charge withinboth the microgel and on the antimicrobial. The exposed surface between microgels can befurther modified by the adsorption of adhesion-promoting proteins such as fibronectin viaelectrostatic interaction. This approach combines a rich interplay of microgel structure andchemistry as a key component in a simple and translatable approach to modulate the surfaceproperties of next-generation biomaterials.

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