scholarly journals Scalable Parallel Approach for High-Fidelity Steady-State Aeroelastic Analysis and Adjoint Derivative Computations

AIAA Journal ◽  
2014 ◽  
Vol 52 (5) ◽  
pp. 935-951 ◽  
Author(s):  
Gaetan K. W. Kenway ◽  
Graeme J. Kennedy ◽  
Joaquim R. R. A. Martins
Keyword(s):  
Steady State ◽  
High Fidelity ◽  
Aeroelastic Analysis

scholarly journals High-Fidelity Fin–Actuator System Modeling and Aeroelastic Analysis Considering Friction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3057
Author(s):  
Jin Lu ◽  
Zhigang Wu ◽  
Chao Yang
Keyword(s):  
System Modeling ◽  
Past Research ◽  
High Fidelity ◽  
Aeroelastic Stability ◽  
Aeroelastic Analysis ◽  
Structural Nonlinearities ◽  
Flutter Boundary ◽  
Actuator System ◽  
Friction Models ◽  
Comparison Of The Results

Both the dynamic characteristics and structural nonlinearities of an actuator will affect the flutter boundary of a fin–actuator system. The actuator models used in past research are not universal, the accuracy is difficult to guarantee, and the consideration of nonlinearity is not adequate. Based on modularization, a high-fidelity modeling method for an actuator is proposed in this paper. This model considers both freeplay and friction, which is easy to expand. It can be directly used to analyze actuator characteristics and perform aeroelastic analysis of fin–actuator systems. Friction can improve the aeroelastic stability, but the mechanism of its influence on the aeroelastic characteristics of the system has not been reported. In this paper, the LuGre model, which can better reflect the friction characteristics, was integrated into the actuator. The influence of the initial condition, freeplay, and friction on the aeroelastic characteristics of the system was analyzed. The comparison of the results with the previous research shows that oversimplified friction models are not accurate enough to reflect the mechanism of friction’s influence. By changing the loads, material, and geometry of contact surfaces, flutter can be effectively suppressed, and the power loss caused by friction can be minimized.

scholarly journals Accelerated and noise-resistant generation of high-fidelity steady-state entanglement with Rydberg atoms

2018 ◽  
Vol 97 (3) ◽  
Author(s):  
Ye-Hong Chen ◽  
Zhi-Cheng Shi ◽  
Jie Song ◽  
Yan Xia ◽  
Shi-Biao Zheng
Keyword(s):  
Steady State ◽  
Rydberg Atoms ◽  
High Fidelity

Study of Unsteady Orifice Flow Characteristics in Hydraulic Oil Lines

1996 ◽  
Vol 118 (4) ◽  
pp. 743-748 ◽  
Author(s):  
Seiichi Washio ◽  
Satoshi Takahashi ◽  
Yonguang Yu ◽  
Satoshi Yamaguchi
Keyword(s):  
Steady State ◽  
Flow Rate ◽  
Pressure Loss ◽  
Flow Characteristics ◽  
High Fidelity ◽  
Flow Rates ◽  
Hydraulic Oil ◽  
Orifice Flow ◽  
Net Pressure ◽  
Clockwise Hysteresis

A technique to measure fluctuating differential pressures with high fidelity has been developed first. When applied to detecting differential pressures generated by an accelerated or decelerated liquid column, the technique turned out to be effective in finding unsteady flow rates. An experimental study has been carried out on periodically changing hydraulic oil flows through an orifice. The results support the validity of the traditional standpoint that characteristics of an unsteady orifice flow can be approximately represented by those of a steady-state one. When inspected in detail, however, a net pressure loss across an orifice in a periodical flow is delayed against a change of the flow rate. The resulting relation between the pressure loss and the flow rate describes a loop with a counter-clockwise hysteresis and a nonlinear twist along the steady-state one. Pressure recovery in a pulsating orifice flow varies with the flow rate almost along the steady-state relation, which is confirmed when the change is not fast.

scholarly journals A hand-off of DNA between archaeal polymerases allows high-fidelity replication to resume at a discrete intermediate three bases past 8-oxoguanine

2020 ◽  
Author(s):  
Matthew T. Cranford ◽  
Joseph D. Kaszubowski ◽  
Michael A. Trakselis
Keyword(s):  
Steady State ◽  
Early Response ◽  
High Fidelity ◽  
Lesion Bypass ◽  
Base Pairs ◽  
Template Strand ◽  
Replication Errors ◽  
Steady State Kinetic ◽  
Hand Off ◽  
Exact Position

AbstractDuring DNA replication, the presence of 8-oxoguanine (8-oxoG) lesions in the template strand cause the high-fidelity (HiFi) DNA polymerase (Pol) to stall. An early response to 8-oxoG lesions involves ‘on-the-fly’ translesion synthesis (TLS), in which a specialized TLS Pol is recruited and replaces the stalled HiFi Pol for bypass of the lesion. The length of TLS must be long enough for effective bypass, but it must also be regulated to minimize replication errors by the TLS Pol. The exact position where the TLS Pol ends and the HiFi Pol resumes (i.e. the length of the TLS patch) has not been described. We use steady-state and pre-steady-state kinetic assays to characterize lesion bypass intermediates formed by different archaeal polymerase holoenzyme complexes that include PCNA123 and RFC. After bypass of 8-oxoG by TLS PolY, products accumulate at the template position three base pairs beyond the lesion. PolY is catalytically poor for subsequent extension from this +3 position beyond 8-oxoG, but this inefficiency is overcome by rapid extension of HiFi PolB1. The reciprocation of Pol activities at this intermediate indicates a defined position where TLS Pol extension is limited and where the DNA substrate is handed back to the HiFi Pol after bypass of 8-oxoG.

An Assessment of the Validity of Quasi-Steady Analysis of Pressure Relief Valves

2019 ◽  
Author(s):  
Christopher Doyle ◽  
William Dempster ◽  
Steven Taggart
Keyword(s):  
Steady State ◽  
High Fidelity ◽  
Cfd Simulations ◽  
Pressure Relief ◽  
Ansys Fluent ◽  
Interaction Processes ◽  
Transient Simulations ◽  
Flow Features ◽  
Pressure Relief Valves ◽  
Computational Fluid Dynamics Cfd

Abstract In this paper, the validity of the commonly used quasi-steady design approach to pressure relief valves (PRV) is examined by comparing detailed steady state conditions of valve behavior directly with transient conditions. To achieve this, a PRV conforming to ASME VIII standards was modelled using the commercial computational fluid dynamics (CFD) package ANSYS FLUENT to account for transient fluid-structure interaction processes. Detailed steady state CFD simulations were conducted using quasi-steady assumptions and compared to high fidelity transient moving mesh simulations to allow the piston forces to be examined. The results indicated that noticeably different magnitudes can occur between steady state and transient simulations; highlighting the possibility of significant differences occurring between quasi steady designed valves and their ultimate performance. In this paper, a single operating condition is examined, using air at 10.3 barg, for a 5231BX refrigeration valve supplied by the Henry Group to highlight the main issues. Analysis has indicated that the differences in performance are generated by temporal, short lived vortices at the piston surface which influences the bulk flow features as the disc accelerates and decelerates; altering the net disc forces when compared to steady state conditions.

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