In this paper, the influence of nose-tip temperature on hypersonic crossflow instability is experimentally investigated using infrared thermal imaging and high-frequency pulsating pressure sensors at Mach 6 for a 7° semi-cone angle 6° attack. The wall ratio (ratio to total incoming temperature) Tw/T0 varies between 0.6 1.3. experimental results show that transition position gradually moves toward tail cone as increases. Wavelet analysis reveals stationary vortices with wave numbers ranging...

With the advancement of artificial intelligence technology, robots are increasingly replacing human labor and playing an important role in production. The research focused on goods transportation, which plays a great society. However, traditional method for transportation was only to use force, very inefficient expensive if applied large scale could contain life risks under dangerous working conditions. Therefore, attempts explore new by using robotics automation system, where ones carry...

An experimental study is conducted on the surface shear stress vector distribution a plate in supersonic jet flow, with focus separation region. The shear-sensitive liquid crystal coating (SSLCC) technique employed for flow visualization and measurement, which based distribution, pattern captured. results demonstrate that nozzle pressure ratio (NPR) main inducement to evolution, high NPR causes region plate, where adverse challenging SSLCC technique. Therefore, an improved measurement method...

The flow field in a hypersonic inlet model at design point of M = 6 has been studied experimentally. focus the current study is to present time-resolved characteristics separation shock around cowl and correlation between oscillation induced by unstart wall pressure fluctuation when state unstart. High-speed Schlieren visualization used capture transient structure. High-frequency transducers are installed on both isolator areas detect dynamic distribution. A schlieren image quantization...

In the hybrid energy storage system of electric vehicles, main objective is to guarantee that dc-bus voltage tracks desired set point quickly and accurately. However, it typically difficult for existing methods provide both short settling time small overshoot, which results in significant fluctuations. To address this issue, paper, we propose a predictive-set-point-modulation-based management control strategy. A lead-compensator-based predictive set-point modulation method designed...

The switched shunting resistor circuit is a classical and practical passive equalization scheme that nevertheless suffers from the voltage imbalance after charging process. It results discrepancy of physical characteristics supercapacitor (SC) cells. In this paper, distributed control strategies with proportional-integral (PI) observer for are analyzed compared. First, equalizing system modeled as observability proved. decentralized consensus their shortages presented. Then, leader-follower...

It is expected, the growing demand for supercapacitor energy storage system (ESS) in which thousands of cells are connected as a stack meeting desired load power. The lifetime ESS dramatically depends on operating thermal effects individual cells. In this paper, temperature-suppression charging strategy proposed to maximize its lifetime. First, current and equivalent series resistance (ESR) construct model, ESR represents degradation degree supercapacitor. Second, maximization equalization...

Separation induced by impinging shock is a fundamental feature in supersonic and hypersonic flows; however, it difficult to predict the pressure plateau due limited theoretical understanding of effect strength. In this study, evolution separation configuration distribution with changes angle examined, equation for predicting based on minimum entropy production proposed. For validation, an experimental device that can measure wall region at high spatiotemporal resolution developed, schlieren...

Current overshoot in the charging is an undesired behavior that accelerates aging of both chargers and batteries. This phenomenon even more severe parallel-connected multicharger systems supercapacitor trams, as overshooting each charger stacked up current. To address this issue, article, we propose a current-overshoot-suppression method for trams. First, system modeling developed motivation article highlighted. Then, cooperative protocol designed to achieve current balancing chargers, set...

Reconfigurable circuits have emerged as a promising cell balancing solution in supercapacitor echelon applications. However, the classical decentralized control method of reconfigurable supercapacitors results high-voltage profiles cells, which degrades lifetime supercapacitors. In this article, we propose consensus-based approach for supercapacitors, where voltages are synchronized and maintained low possible to alleviate aging The switched systems theory graph utilized characterize...

This paper reports an experimental study on the supersonic jet surface flow structure visualization and shear stress field measurement issuing from a rectangular nozzle with extended shelf. The evolution of near-field structures increased Nozzle Pressure Ratio (NPR) is successfully captured by oil flow, infrared detection technology, Shear-Sensitive Liquid Crystal Coating (SSLCC) technique. Results reveal that under smaller NPR, wall similar to without shelf i.e., clean jets, this caused...

Reconfigurable supercapacitor energy storage systems have been a promising choice for powering portable electronics since it omits the requirement of passive balancing elements such as resistors in circuit, which improves efficiency and alleviates thermal heating effect circuit. However, classical decentralized cell method results high voltage profiles cells, degrades lifetime cells repeated charging-discharging cycles. To address this challenge, we propose cooperative approach...

In the hybrid energy storage system of electric vehicles (EVs), supercapacitors (SCs) are configured to supplement high frequency power loads reduce battery strains. Continuous supply and quick response load through bidirectional control is great importance attain balance keep stability bus voltage. this paper, we propose a reference modulation based management strategy tackle problem. Specifically, an adaptive SCs current regulation designed maintain sustainable for SCs. A discrete lead...

Response overshoot is an undesired behavior that acceleraes system aging and even causes damage in high-power electronics system. In this paper, we proposed a current control method for improving dynamic performance of charging systems serve energy-storage urban rails. A controller implemented to reduce the capacitors switching devices Specially, set point automatic adjustment with correction enabled (SPAACE) designed method, aim reducing overshoot. Therefore our can optimize responsiveness...

The internal combustion engine should be enlarged the cylinder diameter for Power requirements. In order to ensure work normally, it is needed compute strength of connecting rod. Through adopting ANSYS software, three-dimensional computational model constructed, and stress analysis carried out. We can learn field process deformation. calculation rod are derived. Using which was calculated from we decide Safety general, meaningful optimize design

An experimental study is conducted on the qualitative visualization of flow field in separation and reattachment flows induced by an incident shock interaction several techniques including shear-sensitive liquid crystal coating (SSLCC), oil flow, schlieren, numerical simulation. The wave generated a wedge Mach 2.7 duct where strength varied from weak to moderate changing angle attack α 8° 10° 12°. stagnation pressure upstream was set approximately 607.9 kPa. SSLCC technique used visualize...

Voltage equalization scheme is used to solve the voltage imbalance problem between serial connected supercapacitors. The inner capacitor instead of terminal based balancing has been proven be more accurate. are traditionally deduced through offline identified model parameters, which variable due effect voltage, interference, and temperature, will cause undesirable deviation. To address problem, we propose an online improve accuracy. achieved by identifying parameters recursive-least square...

Voltage equalization of series-connected supercapacitors (SCs) is practical significance for the life and security supercapacitors. In this paper, we proposed an efficient voltage algorithm based on consensus theory applying switched shunting resistor circuit supercapacitor (SC). equilibrium strategy, a proportional-integral (PI) observer designed to estimate internal capacitance SCs. Then, by comparing observation value with those its neighbors, voltages SCs are balanced before they fully...

The shear-sensitive liquid crystal coating (SSLCC) technique is investigated in the high-speed jet flow of a micro-wind-tunnel. An approach to measure surface shear stress vector distribution using SSLCC established, where six synchronous cameras are used record color at different circumferential view angles. Spatial wall distributions on test obtained velocities. results encouraging and demonstrate great potential wind-tunnel measurement.

In recent years, significant progress have been made in supercapacitor-based portable applications, where the switched-resistors circuit functions as a traditional cell balancing circuit. However, existing charging control methods lack explicit consideration of relatively high system temperature, leading to decrease life span and serious thermal effect. this paper, temperature-suppressed method has proposed keep temperature at low level during process. A proof is provided demonstrate...