The Experts below are selected from a list of 186 Experts worldwide ranked by ideXlab platform

H Dang - One of the best experts on this subject based on the ideXlab platform.

  • theoretical modeling and experimental verification of the motor design for a 500 g micro moving coil linear compressor operating at 90 140 hz
    International Journal of Refrigeration-revue Internationale Du Froid, 2019
    Co-Authors: H Dang, J Li, Yibo Zhao, Tao Zhang, Bangjian Zhao, Yongjiang Zhao
    Abstract:

    Abstract This paper presents the theoretical modeling and experimental verification of the motor design for a micro moving-coil dual-opposed linear compressor operating at 90–140 Hz. A three-dimensional model is built to study the characteristics of its magnetic field and then the magnetic circuit configuration is optimized theoretically. The non-uniform distribution of magnetic field will have an important effect on the direction of the motor force, thereby decreasing the efficiency. Based on theoretical analyses, a 500 g micro linear compressor is built and then coupled with a given micro pulse tube cold finger to test the performance. Experimental results show that the developed compressor achieves an average motor efficiency of 78.6%, and a cooling Power of 1.2 W at 77 K is acquired with an Electric Input Power of 60 W. The experimental results of both linear motor and the cooler system are compared with the theoretical ones and good agreements can be observed.

  • Theoretical modeling and experimental verification of the motor design for a 500?g micro moving-coil linear compressor operating at 90–140?Hz.
    International Journal of Refrigeration, 2019
    Co-Authors: H Dang, Yibo Zhao, Tao Zhang, Bangjian Zhao, Yongjiang Zhao, Jun Tan, Rui Zha, Han Tan, Renjun Xue
    Abstract:

    Abstract This paper presents the theoretical modeling and experimental verification of the motor design for a micro moving-coil dual-opposed linear compressor operating at 90–140 Hz. A three-dimensional model is built to study the characteristics of its magnetic field and then the magnetic circuit configuration is optimized theoretically. The non-uniform distribution of magnetic field will have an important effect on the direction of the motor force, thereby decreasing the efficiency. Based on theoretical analyses, a 500 g micro linear compressor is built and then coupled with a given micro pulse tube cold finger to test the performance. Experimental results show that the developed compressor achieves an average motor efficiency of 78.6%, and a cooling Power of 1.2 W at 77 K is acquired with an Electric Input Power of 60 W. The experimental results of both linear motor and the cooler system are compared with the theoretical ones and good agreements can be observed.

  • theoretical and experimental investigations on the cooling capacity distributions at the stages in the thermally coupled two stage stirling type pulse tube cryocooler without external precooling
    Cryogenics, 2017
    Co-Authors: Jun Tan, H Dang
    Abstract:

    Abstract The two-stage Stirling-type pulse tube cryocooler (SPTC) has advantages in simultaneously providing the cooling Powers at two different temperatures, and the capacity in distributing these cooling capacities between the stages is significant to its practical applications. In this paper, a theoretical model of the thermally-coupled two-stage SPTC without external precooling is established based on the Electric circuit analogy with considering real gas effects, and the simulations of both the cooling performances and PV Power distribution between stages are conducted. The results indicate that the PV Power is inversely proportional to the acoustic impedance of each stage, and the cooling capacity distribution is determined by the cold finger cooling efficiency and the PV Power into each stage together. The design methods of the cold fingers to achieve both the desired PV Power and the cooling capacity distribution between the stages are summarized. The two-stage SPTC is developed and tested based on the above theoretical investigations, and the experimental results show that it can simultaneously achieve 0.69 W at 30 K and 3.1 W at 85 K with an Electric Input Power of 330 W and a reject temperature of 300 K. The consistency between the simulated and the experimental results is observed and the theoretical investigations are experimentally verified.

  • 40 k single stage coaxial pulse tube cryocoolers
    Cryogenics, 2012
    Co-Authors: H Dang
    Abstract:

    Abstract Several 40 K single-stage coaxial high frequency pulse tube cryocoolers (PTCs) have been developed to provide reliable and low-noise cooling for GaAs/AlGaAs Quantum-Well infrared photodetectors (QWIPs). The inertance tubes together with the gas reservoir become the only phase shifter to guarantee the required long-term stability. The mixed regenerator consisting of three segments has been developed to enhance the overall regenerator performance. At present, the cooler prototype has achieved a no-load temperature of 29.7 K and can typically provide 860 mW cooling at 40 K with 200 W Electric Input Power rejecting at 300 K. The performance characteristics such as the temperature stability and ambient temperature adaptability are also presented.

  • Performance investigation on 4.0 W/60 K high frequency coaxial pulse tube cryocoolers.
    2011
    Co-Authors: H Dang, L Wang, K Yang
    Abstract:

    A series of high frequency single-stage coaxial inertance pulse tube cryocoolers for cooling the developing large-scale space-borne long wave IRFRAs have been designed and tested. At present, the typical performance is to provide 4.05 W of cooling Power at 60 K with a 180 W of Electric Input Power at 300 K reject temperature. The cooler prototype including the corresponding control electronic is kept below 10 kg. The 9.0% of Carnot at 60 K has been achieved. The maximum 4.85 W of cooling capacity at 60 K can be achieved when the Input Power increases to 200 W.

Pavel Mokrý - One of the best experts on this subject based on the ideXlab platform.

  • wall plug efficiency analysis of semi active piezoElectric shunt damping systems
    Journal of Vibration and Control, 2016
    Co-Authors: Jan Vaclavik, Milos Kodejska, Pavel Mokrý
    Abstract:

    Analysis of the wall-plug efficiency, i.e. the ratio of reflected and absorbed acoustic Power over the total Electric Input Power, of semi-active vibration control devices based on the principle of the active piezoElectric shunt damping is presented. The vibration suppression element in the considered vibration control device consists of a piezoElectric actuator, which is connected to the active synthetic impedance shunt circuit that emulates a negative capacitance. Two types of Power amplifiers can be used in the implementation of the synthetic impedance: linear (class B, AB) and switching (class D). Using both implementations of the synthetic impedance, a decrease in the transmissibility of vibration by about 30 dB in narrow frequency ranges around 500 Hz, 700 Hz, 900 Hz, and 1.1 kHz has been achieved. The mechanical Input Power transferred from the source of vibration to the vibration control system, the Electric Power flow from the piezoElectric actuator to the active shunt impedance, and the wall-plu...

  • Design of wall-plug efficiency optimized semi-active PiezoElectric Shunt Damping systems
    2013 Joint IEEE International Symposium on Applications of Ferroelectric and Workshop on Piezoresponse Force Microscopy (ISAF PFM), 2013
    Co-Authors: Jan Vaclavik, Pavel Mokrý, Pavel Márton
    Abstract:

    Analysis of the wall-plug efficiency, i.e. the ratio of reflected and absorbed acoustic Power over the total Electric Input Power, of semi-active vibration control devices based on the principle of PiezoElectric Shunt Damping is presented. The vibration suppression element in the considered vibration control device consists of a piezoElectric actuator, which is connected to the active synthetic impedance shunt circuit that emulates a negative capacitance. Two types of Power amplifiers can be used in the implementation of the synthetic impedance: linear (class B, AB) and switching (class D). Strengths and weaknesses of the two aforementioned implementations of the synthetic impedance shunt circuit in the semi-active vibration control device are analyzed. The key factor in the analysis is the wall-plug efficiency. Principles that can enhance the wall-plug efficiency of the device are discussed.

Jan Vaclavik - One of the best experts on this subject based on the ideXlab platform.

  • wall plug efficiency analysis of semi active piezoElectric shunt damping systems
    Journal of Vibration and Control, 2016
    Co-Authors: Jan Vaclavik, Milos Kodejska, Pavel Mokrý
    Abstract:

    Analysis of the wall-plug efficiency, i.e. the ratio of reflected and absorbed acoustic Power over the total Electric Input Power, of semi-active vibration control devices based on the principle of the active piezoElectric shunt damping is presented. The vibration suppression element in the considered vibration control device consists of a piezoElectric actuator, which is connected to the active synthetic impedance shunt circuit that emulates a negative capacitance. Two types of Power amplifiers can be used in the implementation of the synthetic impedance: linear (class B, AB) and switching (class D). Using both implementations of the synthetic impedance, a decrease in the transmissibility of vibration by about 30 dB in narrow frequency ranges around 500 Hz, 700 Hz, 900 Hz, and 1.1 kHz has been achieved. The mechanical Input Power transferred from the source of vibration to the vibration control system, the Electric Power flow from the piezoElectric actuator to the active shunt impedance, and the wall-plu...

  • Design of wall-plug efficiency optimized semi-active PiezoElectric Shunt Damping systems
    2013 Joint IEEE International Symposium on Applications of Ferroelectric and Workshop on Piezoresponse Force Microscopy (ISAF PFM), 2013
    Co-Authors: Jan Vaclavik, Pavel Mokrý, Pavel Márton
    Abstract:

    Analysis of the wall-plug efficiency, i.e. the ratio of reflected and absorbed acoustic Power over the total Electric Input Power, of semi-active vibration control devices based on the principle of PiezoElectric Shunt Damping is presented. The vibration suppression element in the considered vibration control device consists of a piezoElectric actuator, which is connected to the active synthetic impedance shunt circuit that emulates a negative capacitance. Two types of Power amplifiers can be used in the implementation of the synthetic impedance: linear (class B, AB) and switching (class D). Strengths and weaknesses of the two aforementioned implementations of the synthetic impedance shunt circuit in the semi-active vibration control device are analyzed. The key factor in the analysis is the wall-plug efficiency. Principles that can enhance the wall-plug efficiency of the device are discussed.

Sudhakar A. Kulkarni - One of the best experts on this subject based on the ideXlab platform.

  • A two-dimensional finite element analysis of a shape memory alloy laminated composite plate
    Smart Materials and Structures, 2006
    Co-Authors: Basavaraj S Balapgol, Kamal M. Bajoria, Sudhakar A. Kulkarni
    Abstract:

    The deflection and time response of shape memory alloy laminated composite plate are studied using first order shear deformation theory. The composite plate consists of a thin layer of shape memory alloy bonded to an elastomer layer. The governing equations of the plate are developed using the energy balance equations and a two-dimensional model of the shape memory alloy layer. The finite element is modeled with the first order shear deformation theory and equivalent single layer assumptions. The model is validated by comparing the results of the displacements and time responses with the literature. As a specific example, a cantilever composite plate is used for parametric studies. The effect of material properties, Electric Input Power, thickness, thermal conductivity and heat sink strength on deflection and time response is also investigated.

Milos Kodejska - One of the best experts on this subject based on the ideXlab platform.

  • wall plug efficiency analysis of semi active piezoElectric shunt damping systems
    Journal of Vibration and Control, 2016
    Co-Authors: Jan Vaclavik, Milos Kodejska, Pavel Mokrý
    Abstract:

    Analysis of the wall-plug efficiency, i.e. the ratio of reflected and absorbed acoustic Power over the total Electric Input Power, of semi-active vibration control devices based on the principle of the active piezoElectric shunt damping is presented. The vibration suppression element in the considered vibration control device consists of a piezoElectric actuator, which is connected to the active synthetic impedance shunt circuit that emulates a negative capacitance. Two types of Power amplifiers can be used in the implementation of the synthetic impedance: linear (class B, AB) and switching (class D). Using both implementations of the synthetic impedance, a decrease in the transmissibility of vibration by about 30 dB in narrow frequency ranges around 500 Hz, 700 Hz, 900 Hz, and 1.1 kHz has been achieved. The mechanical Input Power transferred from the source of vibration to the vibration control system, the Electric Power flow from the piezoElectric actuator to the active shunt impedance, and the wall-plu...