Three-dimensional numerical simulations are carried out by commercial software STAR-CCM+ to investigate the hydraulic transient and flow behaviours of a prototype pump-turbine during normal shutdown process. The global characteristics pressure fluctuations analysed as runs through turbine mode, into braking finally reversed pump mode. As guide vanes close, rate runner torque both decrease while rotational speed drops in response negative on runner. proposed approach accurately predicts...

Three-dimensional numerical simulation for a prototype pump-turbine has been performed to investigate the transient characteristics and flow behaviors in startup process. The rotational speed, which varies with runner torque inertial of rotating systems, is obtained by hydraulic-force coupling method. To simulate guide vane motions, dynamic overset mesh technique applied good maintenance quality. Comparisons existing experimental results verify validity current method predicting accuracy....

Similarities of the flow in rotor–stator interaction (RSI) affected region (stay vanes, guide and runner domain) prototype model Francis pump-turbines are analyzed using numerical simulations with special attention on influence Reynolds number. The ratios characteristic length velocity between 10.97 2.54; thus, numbers differ by about 28 times. Detailed analysis argues for higher partial load condition, Q = 0.8Qd, severe 0.45Qd. flows distributor (spiral casing, stay vanes well-behaved both...

Purpose The purpose of this paper is to analyze lubrication characteristics a bidirectional thrust bearing in pumped storage, considering the effect thermal elastic deformation pad and collar. Design/methodology/approach This study used fluid–solid interaction (FSI) technique investigate for several typical operating conditions. influences conditions load on were analyzed. Then, various pivot eccentricities investigated effects position. Findings It found that radial tilt angle collar runner...

Integrated sensing and communication (ISAC) is capable of achieving both heterogeneous connectivity highly accurate performance in vehicular networks through effective beamforming design at the roadside unit (RSU). In traditional paradigm, first step predicting kinematic parameters each vehicle then designing optimal matrix, which requires excessively large computational complexity. To tackle this issue, paper proposes a deep learning (DL)-based method that bypasses explicit channel...

In this paper, we study uplink transmission for reconfigurable intelligent surfaces (RIS)-aided orthogonal time frequency space (OTFS) systems to achieve real-time communications and sensing in high-mobility scenarios, which is the urgent requirement various future networks like Internet of Things (IoT) Metaverse. To end, first propose an efficient reliable scheme utilizes delay-Doppler information OTFS facilitate configuration RIS. Specifically, proposed exploits estimated delay Doppler...

This paper develops the refusal testing theory of multi input/output transition system (MIOTS) in direction distributed where multiple testers are involved Centralized MIOTS (where only one tester is used) can be based on two types observers: singular-observer and all-observer For each cases, we define a test architecture propose method to distribute centralized case onto set testers. The singular observer observe channel at time, distribution tests indeed projection global tree local with...

This paper extends the refusal testing for multi input-output systems (MIOTS) to make it also applicable test those implementations with nonlockable output channels. Starting MIOTS theory, we distinguish two types of channels: lockable and nonlockable, develop a more general relation. A generation algorithm is proposed derive complete suite from specification.

In order to test network protocols of distributed and concurrent natures, it is necessary introduce the testing framework. this paper, we first present a formal model system, furthermore, real system architecture proposed. With that, discuss communication issues between components algorithm given. Based on above models algorithm, practical mechanism combining message queue shared memory presented, which provides uniform transparent lower-layer interface for whole system. our practice, proved...

This paper proposes a functional model of the reference implementation in PITS - general Internet protocol conformance test system developed Tsinghua University, China. consists four components: PCO manager, adapter, network adapter and TTCN assistant. Various functions RI are identified classified into these components. With aid RI, is applied to many OSI protocols.

Abstract We discuss the design and performance of a full color transmissive display based on folded Solc filter design. Sharp et. al. suggested use modified as colorswitch for device. Del Pico its direct view device using plastic substrates LCP's to solve some parallax issues. However no details operation were given. The incorporates three individual stacks each responsible producing RGB without filters, this offer high purity brightness along with promise low power consumption. In paper...

Dealing with dynamic networks, specified in natural language, and sometimes featured hierarchical routing architecture, protocols face two hard problems the conformance testing: generation of a large quantity test data automation process. For special case an interior gateway protocol OSPF (open shortest path first), algorithms procedures are proposed to automatically router under taking duty any given network topology. The protocol, mainly its information processing, is formalized as basis...

研究了1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(2-溴-4-硝基-苯并)吡喃,1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(4-硝基-苯并)吡喃,1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(2,4-二硝基-苯并)吡喃及1-正-辛基-3,3-二甲基-吲哚啉-2,2′螺-5′6′-(2-氯-4-硝基-苯并)吡喃在环已烷和甲苯溶液中光致开环过程的瞬态吸收光谱。观察到具有较长寿命的中间体及聚集体的存在。初步提出异构化反应过程的机制中既包含有三重态过程,也有单重态参与。