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Seoksu Moon - One of the best experts on this subject based on the ideXlab platform.

  • the gasoline atomization characteristics and Static Pressure Distribution of tapered nozzle swirl spray
    Transactions of The Korean Society of Mechanical Engineers B, 2007
    Co-Authors: Seoksu Moon, Jaejoon Choi
    Abstract:

    The Static Pressure Distribution, atomization characteristics and velocity Distribution of tapered nozzle swirl spray is analyzed and then compared with original swirl spray. The Static Pressure Distribution inside the swirl spray is measured using a piezoresistive Pressure transducer. Phase Doppler anemometry (PDA) is applied to measure and analyze the droplet size and velocity Distribution of tapered nozzle and original swirl spray. The Static Pressure inside the spray shows the lower value compared to the atmospheric Pressure and this Pressure drop is getting attenuated as the taper angle is increased. The droplet size of tapered nozzle spray shows similar value compared to the original swirl spray at the horizontal mainstream while it shows increased value at vertical mainstream. The deteriorated atomization characteristics of tapered nozzle spray is improved by applying high fuel temperature injection without causing the spray collapse. The velocity results show that the larger portion of fuel is positioned with higher injection velocity, and the smaller portion of fuel is positioned with lower injection velocity with causing spatially non-uniform mixture Distribution.

  • Static Pressure Distribution inside the swirl spray
    10th International Conference on Liquid Atomization and Spray Systems ICLASS 2006, 2006
    Co-Authors: Seoksu Moon, Essam Aboserie, Hyun Dong Shin
    Abstract:

    The authors would like to thank the financial support of CERC (Combustion Engineering Research Center) and NRL (National Research Laboratory) projects of Korea.

  • the Static Pressure Distribution and flow characteristics inside the high Pressure swirl spray
    Journal of ILASS-Korea, 2006
    Co-Authors: Seoksu Moon, Essam Aboserie, Jaejoon Choi
    Abstract:

    The Static Pressure Distribution and flow characteristics inside the high-Pressure swirl spray were investigated by measuring the Static Pressure inside the spray and applying the computational fluid dynamics (CFD). The Static Pressure difference between inner and outer part of spray was measured at different axial locations and operating conditions using a piezo-resislive Pressure transducer. To obtain the qualitative value of swirl motion at different operating conditions, the spray impact-Pressure at the nozzle exit was measured using a piezo-electric Pressure transducer, and the flow angle was measured using a microscopic imaging system. The flow characteristics inside the high Pressure swirl spray was simulated by the 1-phase 3-dimensional CFD model. The effect of Pressure alternations on spray development was discussed with macroscopic spray images and a mathematical liquid film model. The results showed that the Static Pressure drop is observed inside the swirl spray as a result of the dragged air motion and the centrifugal force of the air. The recirculation vortex inside the spray was also observed inside the swirl spray as a result of the adverse Pressure gradient along the axial locations. The results of analytical liquid film model and macroscopic spray images showed that the Static Pressure structure is one of the main parameters affecting the swirl spray development.

  • paper id iclass 06 113 Static Pressure Distribution inside the swirl spray
    2006
    Co-Authors: Seoksu Moon, Essam Aboserie, Hyun Dong Shin
    Abstract:

    The transient Static Pressure of the air located along the centerline of the spray from a DISI Pressure swirl injector was measured for different injection Pressures, fuel temperatures and injection durations. The drop in the Pressure at the centerline was found to be mainly attributed to the swirling liquid and enhanced with the swirling velocity manifested by the injection Pressure. With increasing the injection duration, the Pressure was found to be continuously dropped, although the measured swirling momentum of the liquid reaches an asymptotic value and remains constant until the needle starts to close. This implies that the Pressure at the centerline of a transient spray does not reach its asymptotic value which corresponds to the case of a continuously injected spray. At higher fuel temperature, the air Pressure at the centerline increases and can reach a value more than atmospheric Pressure due to the sudden evaporation of the fuel after been released underneath the needle. This high air Pressure pushes the main stream of the spray to the radial direction resulting in a larger nozzle spray angle which is soon collapsed after a short distance due to the severe expansion of the air and enhanced swirling motion. The link between the Pressure drop across the spray and liquid film profile for different operating conditions was presented using a simple analytical model. The injector was then modified to eliminate the Pressure drop at the center line to have a robust spray that has limited variation with the operating condition and can be used in spray guided gasoline direct injection system. By cutting the nozzle to have a tapered nozzle with an angle less than the flow angle the opened hollow cone shape along the spray streamlines was formed. This shape assists in equalizing the Pressure between the centerline and outer part of spray envelop. The results showed that there is a potential from tapered nozzle spray to be independent of the operating conditions without much sacrifice of the atomization quality.

Hyun Dong Shin - One of the best experts on this subject based on the ideXlab platform.

  • Static Pressure Distribution inside the swirl spray
    10th International Conference on Liquid Atomization and Spray Systems ICLASS 2006, 2006
    Co-Authors: Seoksu Moon, Essam Aboserie, Hyun Dong Shin
    Abstract:

    The authors would like to thank the financial support of CERC (Combustion Engineering Research Center) and NRL (National Research Laboratory) projects of Korea.

  • paper id iclass 06 113 Static Pressure Distribution inside the swirl spray
    2006
    Co-Authors: Seoksu Moon, Essam Aboserie, Hyun Dong Shin
    Abstract:

    The transient Static Pressure of the air located along the centerline of the spray from a DISI Pressure swirl injector was measured for different injection Pressures, fuel temperatures and injection durations. The drop in the Pressure at the centerline was found to be mainly attributed to the swirling liquid and enhanced with the swirling velocity manifested by the injection Pressure. With increasing the injection duration, the Pressure was found to be continuously dropped, although the measured swirling momentum of the liquid reaches an asymptotic value and remains constant until the needle starts to close. This implies that the Pressure at the centerline of a transient spray does not reach its asymptotic value which corresponds to the case of a continuously injected spray. At higher fuel temperature, the air Pressure at the centerline increases and can reach a value more than atmospheric Pressure due to the sudden evaporation of the fuel after been released underneath the needle. This high air Pressure pushes the main stream of the spray to the radial direction resulting in a larger nozzle spray angle which is soon collapsed after a short distance due to the severe expansion of the air and enhanced swirling motion. The link between the Pressure drop across the spray and liquid film profile for different operating conditions was presented using a simple analytical model. The injector was then modified to eliminate the Pressure drop at the center line to have a robust spray that has limited variation with the operating condition and can be used in spray guided gasoline direct injection system. By cutting the nozzle to have a tapered nozzle with an angle less than the flow angle the opened hollow cone shape along the spray streamlines was formed. This shape assists in equalizing the Pressure between the centerline and outer part of spray envelop. The results showed that there is a potential from tapered nozzle spray to be independent of the operating conditions without much sacrifice of the atomization quality.

Ce Yang - One of the best experts on this subject based on the ideXlab platform.

  • investigation on the casing Static Pressure Distribution and stall behaviors in a centrifugal compressor with volute
    International Journal of Mechanical Sciences, 2019
    Co-Authors: Hanzhi Zhang, Ce Yang, Wenli Wang, Jiang Chen, Mingxu Qi
    Abstract:

    Abstract Obtaining the casing Static Pressure Distribution of a centrifugal compressor with volute is beneficial in understanding the compressor stall mechanism and designing the corresponding asymmetric structures to improve the compressor performance and stability. The present study investigates the casing Pressure evolution from the choke to stall operating conditions and focuses on the relationship between the casing Pressure evolutions and stall behavior under different rotational speeds. A total of 72 steady Static Pressure sensors (6 sensors in circumferential direction and 12 in streamwise direction) were mounted around the compressor casing wall to measure the casing Pressure. In the experiment, the steady Pressure data were acquired by averaging the 50 values measured in 1 s. The results show that at the same rotational speed, from the near choke to near stall conditions, the casing Pressure Distribution patterns can be divided into two parts: the single-peak Pressure pattern, from the choke point to maximum efficiency point (transition point), and the double-peak (peak and bulge) Pressure pattern, from the transition point to near stall point. One interesting phenomenon is that the proportions of the flow rate range of the two casing Pressure patterns at different rotational speeds are related to the surge line knee. The vast operating range contraction indicates that the double-peak pattern has more instability at a higher rotational speed, which is linked with the different stall behavior at different rotational speeds. Combined with unsteady full annulus simulations, the leading-edge spillage triggers the impeller long-lived stall earlier at a higher rotational speed, corresponding to the short-lived double-peak Pressure pattern. However, at lower rotational speeds, short-lived diffuser stall occurs owing to the impeller outlet recirculation flow and diffuser inlet separated flow, corresponding to the long-lived double-peak Pressure pattern. Furthermore, the circumferential non-uniform casing Pressure Distribution can indicate the circumferential position of the stall onset and provide a reason for the non-rotating stall in the impeller inlet and partly rotating stall in the diffuser, which is fundamental and beneficial to the compressor flow control system design.

  • casing wall Static Pressure Distribution behavior in a centrifugal compressor with asymmetric inlet outlet structures
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2019
    Co-Authors: Ce Yang, Hanzhi Zhang, Dengfeng Yang, Changmao Yang
    Abstract:

    Asymmetric structures of the bent inlet pipes and outlet volute are typically adopted in centrifugal compressors. By using asymmetric inlet/outlet structures, the uniformity of the compressor’s int...

  • Casing wall Static Pressure Distribution behavior in a centrifugal compressor with asymmetric inlet/outlet structures:
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2018
    Co-Authors: Ce Yang, Hanzhi Zhang, Dengfeng Yang, Changmao Yang
    Abstract:

    Asymmetric structures of the bent inlet pipes and outlet volute are typically adopted in centrifugal compressors. By using asymmetric inlet/outlet structures, the uniformity of the compressor’s int...

  • Non-axisymmetric flow characteristics in centrifugal compressor
    Tuijin Jishu Journal of Propulsion Technology, 2017
    Co-Authors: Lei-lei Wang, Dazhong Lao, Hong Juan Hou, Ce Yang, Yan Zhao Li
    Abstract:

    To investigate the non-axisymmetric flow in centrifugal compressor internal caused by the asymmetric structure of the volute, the combined experimental and numerical methods(Turbulence model choosing S-A model) are used. The results show that the perturbing Pressure wave caused by the high Static Pressure zone of the volute propagates to the upstream in off-design conditions, which brings the non-axisymmetric flow in the compressor. The non-uniform degrees of the Static Pressure Distribution of the volute in the large flow conditions(0.40kg/s) are more obvious than those of the small flow conditions(0.26kg/s). The strong disturbance Pressure wave of the impeller outlet can be transmitted to the circumferential position of the impeller inlet about 180°. In the small flow conditions, the circumferential non-uniform degrees of the radial and tangential velocity of the gas flow through the diffuser are more significant. In the large flow conditions, the air flow fluctuations at volute inlet are more obvious. The blade loading Distribution and its fluctuations are also affected by the the non-axisymmetric flow. The loading fluctuations of the main blades in the large flow conditions are mainly affected by the blade pass frequency, but in the small flow condition, they are mainly influenced by the two times of the blade pass frequency.

Hanzhi Zhang - One of the best experts on this subject based on the ideXlab platform.

  • investigation on the casing Static Pressure Distribution and stall behaviors in a centrifugal compressor with volute
    International Journal of Mechanical Sciences, 2019
    Co-Authors: Hanzhi Zhang, Ce Yang, Wenli Wang, Jiang Chen, Mingxu Qi
    Abstract:

    Abstract Obtaining the casing Static Pressure Distribution of a centrifugal compressor with volute is beneficial in understanding the compressor stall mechanism and designing the corresponding asymmetric structures to improve the compressor performance and stability. The present study investigates the casing Pressure evolution from the choke to stall operating conditions and focuses on the relationship between the casing Pressure evolutions and stall behavior under different rotational speeds. A total of 72 steady Static Pressure sensors (6 sensors in circumferential direction and 12 in streamwise direction) were mounted around the compressor casing wall to measure the casing Pressure. In the experiment, the steady Pressure data were acquired by averaging the 50 values measured in 1 s. The results show that at the same rotational speed, from the near choke to near stall conditions, the casing Pressure Distribution patterns can be divided into two parts: the single-peak Pressure pattern, from the choke point to maximum efficiency point (transition point), and the double-peak (peak and bulge) Pressure pattern, from the transition point to near stall point. One interesting phenomenon is that the proportions of the flow rate range of the two casing Pressure patterns at different rotational speeds are related to the surge line knee. The vast operating range contraction indicates that the double-peak pattern has more instability at a higher rotational speed, which is linked with the different stall behavior at different rotational speeds. Combined with unsteady full annulus simulations, the leading-edge spillage triggers the impeller long-lived stall earlier at a higher rotational speed, corresponding to the short-lived double-peak Pressure pattern. However, at lower rotational speeds, short-lived diffuser stall occurs owing to the impeller outlet recirculation flow and diffuser inlet separated flow, corresponding to the long-lived double-peak Pressure pattern. Furthermore, the circumferential non-uniform casing Pressure Distribution can indicate the circumferential position of the stall onset and provide a reason for the non-rotating stall in the impeller inlet and partly rotating stall in the diffuser, which is fundamental and beneficial to the compressor flow control system design.

  • casing wall Static Pressure Distribution behavior in a centrifugal compressor with asymmetric inlet outlet structures
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2019
    Co-Authors: Ce Yang, Hanzhi Zhang, Dengfeng Yang, Changmao Yang
    Abstract:

    Asymmetric structures of the bent inlet pipes and outlet volute are typically adopted in centrifugal compressors. By using asymmetric inlet/outlet structures, the uniformity of the compressor’s int...

  • Casing wall Static Pressure Distribution behavior in a centrifugal compressor with asymmetric inlet/outlet structures:
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2018
    Co-Authors: Ce Yang, Hanzhi Zhang, Dengfeng Yang, Changmao Yang
    Abstract:

    Asymmetric structures of the bent inlet pipes and outlet volute are typically adopted in centrifugal compressors. By using asymmetric inlet/outlet structures, the uniformity of the compressor’s int...

Xiaoping Chen - One of the best experts on this subject based on the ideXlab platform.

  • Static Pressure Distribution characteristics of powders stored in silos
    Chemical Engineering Research & Design, 2020
    Co-Authors: Yangyang Chen, Cai Liang, Xin Wang, Xiaoping Chen
    Abstract:

    Abstract Static Pressure Distribution of the wall is essential to the optimal characteristics and discharge stability of the powder from products (bulk solids) in a silo. A Geocomp Shear Trac-II system was used to measure the flow properties of three different types of material, with an emphasis on the determining the best results in experiments using a special test silo with conical hopper dependent on the Static Pressure Distribution of the silo wall. Experimental results shows that with an increase in height from the outlet, the Pressure in a hopper gradually increases, while the silo wall’s normal Pressure in the cylinder decreases. The maximum Pressure appears at the silo-hopper junction. Three different material types are chosen based on their ability to have a weakening effect on horizontal Pressure. With the increase in particle size, the horizontal Pressure in the silo junction remained constant. In the cylinder cross section, the larger the particle size, the higher the horizontal Pressure. Meanwhile, the vertical Pressure Distribution shows the opposite trend. With the increase in moisture content, horizontal Pressure increases, and the silo wall’s normal Pressure decreases. The influence of the moisture content on the vertical Pressure of the cone cross section is weak. In the cylinder cross section, the vertical Pressure increases with the increase in moisture content. The experimental data created in this study can serve as a reference to guide the design of new silos as well as the maintenance tasks of established silos. This paper can serve as a reference on what silo parts must be reinforced under higher Pressure during the unloading process.