Double Cavity Research Articles

Design and Modification of Forming Tool in Press Machine

Abstract: Now-a-days Currently they are using single cavity tool in company by using that we are identified so many problems like high production cost, less production ratio and excess time required for mass production. To solve this problem we are introducing double cavity tool instead of single cavity tool. By using cad software we are designing the double cavity tool. The aim of this project is to increase the production rate and also decrease economically for Pneumatic Press machine. For achieving that, introducing double cavity tool instead of single cavity tool and also fool proof. And analyze those tools by using ANSYS software and manually in industry. This project can be used in industry and also very helpful for unskilled labor to work without mistake.

An innovative small-sized double cavity PTC under investigation and comparison with a conventional PTC

In this study, a novel evacuated double cavity receiver parabolic trough collector is being examined in detail and compared with a conventional geometry. The collectors were investigated optically and thermally. Firstly, the optical efficiency of the cavity configuration was optimized and a tracking error analysis was conducted. Next, the collectors were optimized regarding the mass flow rate and the thermal analysis followed. Syltherm-800 was used as the working medium of this analysis. Several different inlet temperatures were examined (20°C–300°C) considering the optimum volumetric flow rate in each case. The comparison showed a clear prevalence of the suggested collector in the whole operating range with the mean enhancement reaching approximately 16%. These geometries were, also, compared with the same to the double cavity geometry, where the inner cavity surfaces are non-selective. The results indicated that the non-selective configuration exceeds the conventional one in thermal performance by 10.73% on average. The simulation results were, also, validated with several theoretical models and a sufficient agreement was achieved. In particular, the deviations were found to be less than 5% in both models for the Nusselt number and the Darcy friction factor. SolidWorks was used as the design and the simulation tool of this study.

Preparation and Evaluation of an Azobenzenediamide Bridged bis(β-Cyclodextrin)-Bonded Chiral Stationary Phase for HPLC.

An azobenzenediamide bridged bis(β-cyclodextrin) chiral stationary phase (AZCDP) was prepared, and its high-performance liquid chromatography performance in reversed-phase and polar organic modes was evaluated by chiral probes, including triazoles, flavanones, amino acids and β-blockers. The results showed that AZCDP had strong chiral separation ability and the 40 chiral compounds were successfully resolved, of which 32 were completely separated (Rs ≥ 1.5) and the best enantioresolution was up to 3.93 within 20min under a wide range of pH value and temperature. The separation ability of AZCDP with double cavities was significantly better than common CD-CSPs with single cavity, which was related to the synergistic inclusion effect. Compared with the previously reported stilbene (C=C)-bridged CSP, AZCDP with azobenzene (N=N)-bridged had a wider resolution range. For example, it could resolve myclobutanil, pindolol, carteolol, betaxolol, bevanolol and bitertanol, which could not be resolved before, and should be related to the fact that the flexible N=N was more compatible with the synergistic inclusion between cavities than the rigid C=C bridge group. The azobenzenediamide bridging group could also provide hydrogen bond, π-π and other sites, which was conducive to chiral separations.

Effect of aspect ratio and nonuniform temperature on mixed convection in a double lid-driven cavity

The impact of aspect ratio and nonuniform temperature on mixed convection in an enclosure is examined numerically. The chosen shape is an enclosure with a sinusoidal temperature TH in its lower wall, while the upper wall is considered adiabatic. The sidewalls of the cavity move at a descending speed with a uniform temperature TC. The inspection is performed for different Richardson numbers and aspect ratios (AR) varying from 0.25 to 5, while the numbers of Prandtl (Pr = 0.71) and Grashof (Gr = 104) remain constant. The isothermal, streamline, and Nusselt numbers flow distributions inside the cavity are highlighted and discussed. Compared to uniform heating, significant changes in the flow rate are observed when receiving nonuniform heating on the lowest cavity surface. Two cells of flow rotating in opposing directions are formed inside the cavity when the cavity aspect ratio AR = 0.25. When the cavity aspect ratio becomes higher than the unity, these cells change with the development of Ri; they take an oval form and move to the heated side. The non-uniform heating yielded a sinusoidal localized thermal exchange rate with the lowest amounts at the edges and considerable amounts at the bottom center (Ri = 1 and 100).

Development of thermoelectric energy generator with high area density stacked polysilicon thermocouples

A semiconductor thermoelectric energy generator (TEG) with thermocouples in high area density is proposed in this work. Different from the common TEGs with co-planar thermocouples, the high area density is achieved by placing the P-thermoleg above the N-thermoleg into a stacked thermocouple, which is then insulated above and below by double cavity to retain sufficient thermal gradient. The TEG voltage factor is therefore increased by a factor of 2. For a TEG implemented by standard CMOS process (TSMC D35 2P4M), simulation shows that the stacked thermocouple of size 58 × 2 × 0.180 µm P-type thermoleg above 64 × 2 × 0.275 µm N-type thermoleg can reach optimal performance. Measurement results of a 5 × 5 mm2 TEG chip by semiconductor foundry service confirm the power factor of 0.075 μW/cm2K2 and the voltage factor of 7.004 V/cm2K are 1.7 x and 2.5 x, respectively, of that in TEG with co-planar thermocouples. This performance is the best of all TEGs with polysilicon thermocouples by standard CMOS process.

Vibro-acoustic analysis of a circumferentially coupled composite laminated annular plate backed by double cylindrical acoustic cavities

The current work focuses on the vibro-acoustic analysis of fluid-structure coupling system composed of a circumferentially coupled composite laminated annular plate and two cylindrical acoustic cavities considering arbitrary acoustic impedance. By employing the unified Ritz energy scheme in conjunction with the first-order shear lamination scheme, the acoustic and structural models in the studied physical system are reasonably established, where the required structural and plate-cavity continuity conditions are taken into account by means of the coupled spring technology and work, respectively. One-dimensional and two-dimensional orthogonal polynomials with the aid of the Fourier harmonic functions are separately applied to construct the variables functions of structural and acoustic domains without meshing requirements. The convergence and correctness of the developed prediction model including various physical parameters are carefully investigated through several comparative examples as well as vibro-acoustic experiment analysis, which illustrates the good insight in the vibro-acoustic mechanism of the studied physical system. Some parametric analysis respecting the effect of structural/acoustic boundaries, cavity depth, coupling radius and material parameter etc. on the coupled vibro-acoustic performance is implemented in detail, which may give some guidance for the low-noise pre-design of circumferentially coupled laminated annular plate.

Influence of double cavities on anchors capacity

Abstract Soil is considered an essential component of the factors that are affecting the structures. Due to the problems that are faced under various conditions while the structure is in use, the behavior of the soil is complex. The presence of cavities inside various types of soil, such as gypsum soil and the soil of some old towns, is one of its difficult problems. The formation of these cavities is due to natural and industrial causes, one of the natural causes being the dissolve of salts inside them. As for the industrial one, it is due to the presence of some old buildings. The presence of this type of cavities affects the life of the structures and as a result, it creates cracks in the foundation, therefore reducing the life of the structures. The unexpected formation of cavities inside the soil was based mainly on some practical experiments for this research. Two cavities have been created inside the soil with different locations from the anchor to study the capacity of the anchor. The results showed that the presence of the cavity affects the capacity of the anchor according to its location from the plate as well as from the rod. The closer the cavity are to the plate; the capacity have been decreased by a certain percentage depending on the distance from the plate anchor.

Design and simulation of cavity and piezoelectric material structure in segmented doubly clamped piezoelectric energy harvester

AbstractIn view of providing consistent power to remotely situated microelectronic devices, this paper proposes a full‐length cavity‐based novel segmented doubly clamped piezoelectric energy harvester (DCPEH). The paper starts with the analysis of different possible configurations of segmented DCPEH beam corresponding to single, double, and triple cavity systems involvement. It has been observed that for full‐length single cavity involvement, the segmented DCPEH beam is resonate at minimum value (70 Hz) of resonance frequency. However, the observed value of output power response (76 mW) at such low resonant frequency is not so appropriate. Therefore, the performance of full‐length cavity‐based segmented DCPEH beam has been further investigated for series and parallel composite structural design of PMN‐35%PT (M1) and PZT‐5H (M2) piezoelectric materials. The improved value of output power (313 mW) response at low (68.8 Hz) resonant frequency has been achieved with M2‐M1 series composite form of piezoelectric materials.

Mixed convection in a double lid-driven rectangular cavity filled with hybrid nanofluid subjected to non-uniform heating using finite-volume method

Mixed convection in a double lid-driven rectangular cavity filled with hybrid nanofluid subjected to non-uniform heating using finite-volume method

Quantum versus classical correlations in a double cavity optomechanical system

In a bipartite quantum state, where the total correlations can be divided into classical and quantum parts, Henderson and Vedral (2001 J. Phys. A: Math. Gen. 34 6899) have conjectured that classical correlations should not be less than quantum ones. Here, we consider two symmetrical states of two driven optomechanical cavities coupled to a squeezed photon source and exposed to Markovian noise and damping. The total and quantum correlations are systematically quantified by quantum mutual information and quantum discord respectively. Interestingly, we analytically demonstrate that classical correlations in the considered two-mode Gaussian states are always superior to quantum ones, whatever the physical and environmental parameters are. Moreover, using experimentally accessible parameters, we show numerically the existence of a domination of classical correlations over quantum ones under various circumstances. Finally, we found that quantum, as well as classical correlations, have similar behaviors under the effect of thermal decoherence, squeezing and optomechanical coupling. Yet, classical correlations are more strong and robust.

Investigation of microwave enhanced catalytic degradation of VOCs with a novel double ridge field compressed cavity

Volatile organic compounds (VOCs) are common organic pollutants that are harmful to human and the environment. Degradation of VOCs has aroused widespread concern. Catalytic oxidation is considered as an effective method to degrade VOCs. Microwave heating is a promising technology for heterogeneous catalytic gas–solid reactions, which is considered as an alternative to conventional conductive heating. Here, microwave enhanced catalytic degradation of VOCs were carried out in a novel double ridge field compressed cavity, in which Cu-Mn/AC catalyst was applied. The relative permittivity of Cu-Mn/AC at different temperatures were obtained by neural network. Further, based on the relative permittivity obtained, numerical simulations for the double ridge field compressed cavity were conducted at 2.45 GHz by a coupled three-dimensional electromagnetic-thermal model using COMSOL Multiphysics software. The simulation results of electric field distribution and temperature distribution in cavity present similar trend to the experimental results. Experimentally, the degradation of ethanol, benzene and acetone were carried out in this reactor for 50 W and 70 W at 2.45 GHz with the concentration and gas flow rate of 1000 ppm and 18 L/min. At 70 W and 2.45 GHz, the degradation efficiency of ethanol, benzene and acetone reached 99%, 70% and 99%, leading higher energy efficiency than other VOCs degradation methods.

Theoretical and experimental study on gain competition adjustment of intracavity pumped dual-wavelength optical parametric oscillator using an aperiodically poled lithium niobate at approximately 3.30 and 3.84 μm

An intracavity pumped dual-wavelength optical parametric oscillator based on a single MgO:APLN crystal at approximately 3.30 and 3.84 μm was studied using a folded-type double cavity, which consists of a 1.06 μm resonator and dual-wavelength optical parametric oscillator. With the maximum incident diode power of 43.84 W, the maximum output powers of 1.43 W at 3.30 μm and 2.47 W at 3.84 μm were obtained under T = 70%@1.57 μm and T = 25%@1.47 μm at a repetition rate of 40 kHz, corresponding to conversion efficiencies of 3.26% and 5.63%, respectively. The pulse widths of 11.35 ns at 3.30 μm and 13.17 ns at 3.84 μm were obtained synchronously. A dual-wavelength optical parametric energy conversion model was set up to simulate the influence of the transmittance at resonant signal wavelengths on the output power of idler wavelengths. Both theoretical and experimental results demonstrated that the relationships in output power between 3.30 and 3.84 μm can be affected by adjusting the transmittance at signal wavelengths.

A Plus Shaped Cavity in Optical Fiber Based Refractive Index Sensor.

The optical fiber grating sensors have strong potential for the detection of biological samples. However, a careful effort is still in demand to enhance the performance of existing grating sensors especially in biological sensing. Therefore, in this work, we have introduced a novel plus shaped cavity (PSC) in optical fiber model and used it for the detection of haemoglobin (Hb) refractive index (RI). The numerical analysis of designed model is done by the testing of single and double vertical slots cavity in optical fiber core structure. The testing of designed sensor model is done at the wavelength of 800 nm at which the RI of oxygenated and deoxygenated Hb is 1.392 and 1.389, respectively. The analysis of reported PSC sensor model is done in the wide range of Hb RI from 1.333 to 1.392. The tested range of RI corresponds to the Hb concentration from 0 to 140 gl-1. The obtained results states that for the tested range of RI, the autocorrelation coefficient of R2 = 99.51 % is achieved. The analysis of projected work is done by using finite difference time domain (FDTD) method. The introduction of PSC can increase in sensitivity. In proposed PSC, the length and width of created slots are [Formula: see text] and [Formula: see text], respectively, which is quite enough to observe the response of analytes RI. This can minimize the creation of multiple gratings required for observing the analyte response.

Quantifying quantum correlations in a double cavity–magnon system

Quantifying quantum correlations in a double cavity–magnon system

Vibro-acoustic characteristics analysis of the rotary composite plate and conical–cylindrical double cavities coupled system

PurposeThe purpose of the study is to obtain and analyze vibro-acoustic characteristics.Design/methodology/approachA unified analysis model for the rotary composite laminated plate and conical–cylindrical double cavities coupled system is established. The related parameters of the unified model are determined by isoparametric transformation. The modified Fourier series are applied to construct the admissible displacement function and the sound pressure tolerance function of the coupled systems. The energy functional of the structure domain and acoustic field domain is established, respectively, and the structure–acoustic coupling potential energy is introduced to obtain the energy functional. Rayleigh–Ritz method was used to solve the energy functional.FindingsThe displacement and sound pressure response of the coupled systems are acquired by introducing the internal point sound source excitation, and the influence of relevant parameters of the coupled systems is researched. Through research, it is found that the impedance wall can reduce the amplitude of the sound pressure response and suppress the resonance of the coupled systems. Besides, the composite laminated plate has a good noise reduction effect.Originality/valueThis study can provide the theoretical guidance for vibration and noise reduction.

Unsteady numerical investigation of nanofluid mixed convection within a cubic cavity with periodic motion of double oscillatory walls

PurposeThe purpose of this study is to investigate the impact of the oscillatory movement on heat transfer within a double periodic lid-driven cubic enclosure filled with copper-water nanofluid and to figure out how the oscillations impact the fluid flow and thermal behavior inside the enclosure. The authors asserted that this study will help to improve the heat transfer efficiency and the thermal performance of various technical engineering equipments.Design/methodology/approachThe cubic enclosure is heated differentially; the left side is cold, the right one is warm and the remaining walls are insulated. Based on the movement directions of the upper and bottom lids, two cases for lid-driven walls are examined (Case 1: same movement for both lids; Case 2: opposite movement for the lids). The finite volume approach was implemented to solve the time-dependent three-dimensional momentum and energy equations, adopting the power low as a scheme of resolution. The numerical study was carried out for a range of parameters: volume fraction (0 ≤ φ ≤ 0.06), Richardson number (0.1 ≤ Ri ≤ 10), non-dimensional lid frequency (2π/50 ≤ Ω ≤ 2π/10) and fixed Grashof number 105.FindingsThe numerical simulations were executed for two different cases of the direction of the motion of the oscillatory lids. Based on the findings obtained, decreasing the Richardson number with low lids frequency gives the best heat transfer enhancement for both cases. Furthermore, in the same conditions, swapping from Case 2 to Case 1 leads to enhancing the maximum average Nusselt number obtained by 29.74%. At a high Richardson number, using high lids frequency increases the heat transfer rate compared to using low lids frequency (an enhancement of 4.32% for Case 1 and 3.63% for Case 2). The best heat transfer rate was established for Case 1 when the lids move positively, transporting the cold flow to the hot side. In all cases, increasing the concentration of nanoparticles improves the heat transfer.Originality/valueThe current study gives an understanding of the problem of mixed convection in a cubic enclosure with oscillatory walls, which has received little attention. And also, there has been no study published on unsteady mixed convection within a double oscillatory lid-driven cavity.

Heterotrimetallic Double Cavity Cages: Syntheses and Selective Guest Binding

AbstractA strategy for the generation of heterotrimetallic double cavity (DC) cages [PdnPtmL4]6+ (DC1: n=1, m=2; and DC2: n=2, m=1) is reported. The DC cages were generated by combining an inert platinum(II) tetrapyridylaldehyde complex with a suitably substituted pyridylamine and PdII ions. 1H and DOSY nuclear magnetic resonance spectroscopy (NMR) and electrospray ionization mass spectrometry (ESIMS) data were consistent with the formation of the DC architectures. DC1 and DC2 were shown to interact with several different guest molecules. The structure of DC1, which features two identical cavities, binding two 2,6‐diaminoanthraquinone (DAQ) guest molecules was determined by single‐crystal X‐ray crystallography. In addition, DC1 was shown to bind two molecules of 5‐fluorouracil (5‐FU) in a statistical (non‐cooperative) manner. In contrast, DC2, which features two different cage cavities, was found to interact with two different guests, 5‐FU and cisplatin, selectively.

Heterotrimetallic Double Cavity Cages: Syntheses and Selective Guest Binding.

A strategy for the generation of heterotrimetallic double cavity (DC) cages [Pd n Pt m L4]6+ (DC1: n=1, m=2; and DC2: n=2, m=1) is reported. The DC cages were generated by combining an inert platinum(II) tetrapyridylaldehyde complex with a suitably substituted pyridylamine and PdII ions. 1H and DOSY nuclear magnetic resonance spectroscopy (NMR) and electrospray ionization mass spectrometry (ESIMS) data were consistent with the formation of the DC architectures. DC1 and DC2 were shown to interact with several different guest molecules. The structure of DC1, which features two identical cavities, binding two 2,6‐diaminoanthraquinone (DAQ) guest molecules was determined by single‐crystal X‐ray crystallography. In addition, DC1 was shown to bind two molecules of 5‐fluorouracil (5‐FU) in a statistical (non‐cooperative) manner. In contrast, DC2, which features two different cage cavities, was found to interact with two different guests, 5‐FU and cisplatin, selectively.

Acquisition Method for Micro-gap Oil Film Morphology of Hydrostatic Workbench Having Double Rectangular Cavities under Working Conditions of High-Speed and Heavy-Load

When the hydrostatic workbench is running under high-speed overload conditions, the friction by-product is partially placed, causing the micro-gap oil film to be smaller, and the tribology is exposed. The oil film morphology of hydrostatic workbench directly affects its lubrication performance, and the oil film morphology is determined by deformation of bearing friction pairs and the oil film morphology is extremely difficult to obtain. This study will provide an acquisition method for the oil film morphology through the deformation of the bearing friction pair, and the deformation prediction of hydrostatic workbench having double rectangular cavities in heavy type vertical lathe has studied based on ANSYS WORKBENCH, and these are helpful to further investigate oil film shape under the working conditions of high-speed and heavy-load. The oil film clearance test rig was established, and the simulation results were verified, which verified the effectiveness of the proposed numerical simulation method. It can be concluded that the rotational speed has a greater impact on the oil film thickness than that of load, and the oil film thickness of downstream side is smaller than that of upstream side, and oil film thickness changes more quickly inside of oil sealing edge than that of outside, and the friction behavior and failure mechanism of this kind of bearing are proved.

Coherent Combination of Power in Space With Two X-Band Gigawatt Coaxial Multi-Beam Relativistic Klystron Amplifiers

The power capacity of an individual high power microwave (HPM) generator is severely limited by internal electric field breakdown, and the problem becomes more serious for long pulse and high frequency bands. One of the promising solutions to overcome this limitation is coherent combination of power in space. To realize coherent combination of power in space, the HPM generators must operate at the same frequency and stable phase differences. We presented an improved X-band gigawatt coaxial multi-beam relativistic klystron amplifier (CMB-RKA) with high phase stability. Two double gap buncher cavities were designed to improve the beam wave interaction efficiency, and decrease the distance for the modulated intense relativistic electron beam to reach its maximum, which significantly decrease the phase jitter due to the fluctuation of electron beam voltage and improve the phase stability of the CMB-RKA. Experimentally, the two X-band gigawatt CMB-RKA demonstrated the capability of coherent combination of power in space, typically of the combined efficiency of about 95% with the combined pulse width of 150 ns.