• Title/Summary/Keyword: Cross-flow type

Search Result 300, Processing Time 0.03 seconds

Performance and Internal Flow of a Cross-Flow Type Hydro Turbine for Wave Power Generation (파력발전용 횡류형 수력터빈의 성능 및 내부유동)

  • Choi, Young-Do;Cho, Young-Jin;Kim, You-Taek;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
    • /
    • v.11 no.3
    • /
    • pp.22-29
    • /
    • 2008
  • Clean and renewable energy technologies using ocean energy give us non-polluting alternatives to fossil and nuclear-fueled power plants to meet establishment of countermeasures against the global warming and growing demand for electrical energy. Among the ocean energy resources, wave power takes a growing interest because of its enormous amount of potential energy in the world. Therefore, various types of wave power conversion system to capture the energy of ocean waves have been developed. However, suitable turbine type is not normalized yet because of relatively low efficiency of the turbine systems. The purpose of this study is to investigate the internal flow and performance characteristics of a cross-flow type hydro turbine, which will be built in a caisson for wave power generation. Numerical simulation using a commercial CFD code is conducted to clarify the effects of the turbine rotation speed and flow rate variation on the turbine characteristics. The results show that the output power of the cross-flow type hydro turbine with symmetric nozzle shape is obtained mainly from Stage 2. Turbine inlet configuration should be designed to obtain large amount of flow rate because the static pressure and absolute tangential velocity are influenced considerably by inlet flow rate.

Fabrication and Performance Demonstration of the 20kW Class Inverted-type Cross-flow Turbine Based on Computational Fluid Dynamics Analysis (전산유체역학 해석에 기반한 20kW급 도립형 횡류수차의 제작 및 성능 실증)

  • Ham, Sangwoo;Choi, Ji-Woong;Jeong, Changho;Kim, Taeyun;Choi, Sangin;Jin, Glenn Young;Lee, Jeong Wan;Ha, Hojin
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.20 no.2
    • /
    • pp.107-119
    • /
    • 2021
  • The cross-flow turbine is one of the most famous and widely used hydraulic power systems for a long time. The cross-flow turbine is especially popular in many countries and remote regions where off-grided because of its many benefits such as low cost, high efficiency at low head, simple structure, and easy maintenance. However, most modern turbines, including the cross-flow turbine, are unsuitable for the ultra-low head situation, known as less than 3m water head or zero head with over 0.5m/s flow velocity. In this study, we demonstrated a 20kW class inverted-type cross-flow turbine's performance. First, we reevaluated our previous studies and introduced how to design the inverted-type cross-flow turbine. Secondly, we fabricated the 20kW class inverted-type cross-flow turbine for the performance test. And then, we designed a testbed and installed the turbine system in the demonstration facility. In the end, we compare the demonstration with its previous CFD results. The comparing result shows that both CFD and real model fitted on guide vane angle at 10 degrees. At the demonstration, we achieved 42% turbine efficiency at runner speed 125 RPM.

Experimental Study on the Performance of a Cross-Flow Fan with Various Diameter Ratios of Impeller and Rearguider Shapes (임펠러 직경비 및 리어가이더 형상변화가 횡류홴 성능에 미치는 실험적 연구)

  • Kim, H.S.;Kim, D.W.;Yoon, T.S.;Park, S.K.;Kim, Youn-J.
    • 유체기계공업학회:학술대회논문집
    • /
    • 2003.12a
    • /
    • pp.391-396
    • /
    • 2003
  • A cross-flow fan relatively produces higher dynamic pressure at low speed because a working fluid passes through an impeller blade twice and blades have a forward curved shape. The performance of a cross-flow fan is influenced 25% by the impeller, 60% by the rearguider and the stabilizer, and 15% by the heat exchanger. At the low flow rate, there exist a rapid pressure head reduction, a noise increase and an unsteady flow against a stabilizer and a rearguider. The purpose of this study is to investigate the reciprocal relation among each parameter Experiments are conducted to study the effects of a rearguider and a diameter ratio of impeller on the performance analysis of a cross-flow fan. Comparing with the rearguider of radial type, the Archimedes type shows excellent results for various diameter ratios.

  • PDF

Design of the recuperator for the gas turbine/fuel cell hybrid power generating system (가스터빈/연료전지 혼합발전 시스템의 열교환기 설계)

  • Kwak, Jae-Su;Yang, Soo-Seok;Lee, Dae-Sung
    • Proceedings of the KSME Conference
    • /
    • 2004.04a
    • /
    • pp.2105-2110
    • /
    • 2004
  • Plate-fin type recuperators for the gas turbine/fuel cell hybrid power generating system were designed using commercial design software, MUSE. Heat transfer efficiency and total pressure drop in the recuperator were calculated to confirm required recuperator performance. Both counter flow and cross flow type plate-fin recuperators were designed. Results show that the counter flow type has higher efficiency and short core length, but the cross flow type is simpler to construct because the cross flow type does not need additional distributors. Two or three headers for the each recuperator core will be designed and tested to evaluate best header design. The designed recuperators and headers which will be designed later will be constructed, tested, and used in gas turbine/fuel cell hybrid power generating system.

  • PDF

A Study on the Development of Cross-flow Type Vertical Axis Wind Turbine (횡류형 수직축 풍력터빈 개발에 관한 연구)

  • Hwang, Yeong-Cheol;Choi, Young-Do;Kim, Ill-Soo;Lee, Young-Ho
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2009.11a
    • /
    • pp.493-493
    • /
    • 2009
  • Recently, small vertical axis wind turbine attracts attention because of its clean, renewable and abundant energy resources to develop. Therefore, a cross-flow type wind turbine is proposed for small wind turbine development in this study because the turbine has relatively simple structure and high possibility of applying to small wind turbine. The purpose of this study is to investigate the effect of the turbine‘s structural configuration on the performance and internal flow characteristics of the cross-flow turbine model using CFD analysis. The results show that guide nozzle should be adopted to improve the performance of the turbine. Optimization of the nozzle shape will be key-importance for the high performance of the turbine.

  • PDF

An Experimental Study on the Transmission Loss of Perforated Tube Mufflers (다공관 소음기의 투과손실에 관한 실험적 연구)

  • 김찬묵;사종성;방극호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2002.05a
    • /
    • pp.346-352
    • /
    • 2002
  • This paper is the experimental study to estimate the influence of various design parameters on the performance of mufflers with perforated tubes and through-flow partitions. Muffler types considered in the present work include through-flow chamber, through-flow chamber with partition, and cross-flow chamber. The influences of the design parameters on the performance of the mufflers can be outlined as follows. In the case of the through-f]ow type mufflers, increasing the tube thickness and the hole diameter of the perforated tubes does not change the maximum value of the transmission loss but decrease the cutoff frequency. In the case of the through-flow with partitions type mufflers, it is shown that combining a fe w short chambers and long chambers can modify the frequency locations of the resonance frequencies to optimize the performance of the mufflers. For the case of the cross-flow type mufflers, it is shown that the transmission loss of the mufflers is mainly affected by the lower porosity when the porosities are different in both sides of the plug. Overall, it is shown that performance of the through-flow type with partition type mufflers is excellent in the lower frequency region, where the cross-flow type mufflers have better performance in the higher frequency region.

  • PDF

Computational Analysis of an Inverted-type Cross-flow Turbine for Ultra-low head Conditions (전산유체역학을 이용한 초저낙차 상황에서의 도립형 횡류수차의 해석 및 설계 최적화)

  • Ham, Sangwoo;Ha, Hojin;Lee, Jeong Wan
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.18 no.4
    • /
    • pp.76-86
    • /
    • 2019
  • The cross-flow turbine is a key hydraulic power system that is widely due to low costs, high efficiency, and low maintenance. In particular, the cross-flow turbine considered as the most suitable turbine for low head situations as it is known to operate down to 5 m of water head. However, the conventional cross-flow turbine is unsuitable for ultra-low head situations with less than a 3 m water head. In this study, we propose an inverted-type cross-flow turbine to overcome the limitations of conventional cross-flow turbines under ultra-low head situations. First, we described the limitations of conventional turbines and suggested a new turbine for the ultra-low head circumstances. Second, we investigated the performance of the new turbine using CFD analysis. Results demonstrated the effects of the design parameters, such as number of blades and rotor diameter ratio, on the performance of the suggested turbine. As a result, we developed an inverted-type cross-flow turbine with up to 60% efficiency under low water head conditions.

The Experimental Study of the Hybrid Cooling Tower using Cross and Counter Type Fills (직교.대향류 충진재를 이용한 하이브리드 냉각탑에 대한 실험적 연구)

  • Jun, C.H.;Lee, H.S.;Lee, H.C.;Moon, C.G.;Kim, J.D.;Kim, Eun-Pil;Yoon, J.I.
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2005.11a
    • /
    • pp.236-237
    • /
    • 2005
  • An experimental study on the Hybrid Cooling Tower has been done having a rated capacity of 3RT. Counter flow type fill, cross flow type fill and hybrid-type fill which is combined with two type fills as previously stated having a height of 0.3m have been used in the 0.8m${\times}$0.4m${\times}$1.9m dimensional tower respectively. The heat exchanger is consisting of 2 or 3 rows. The relevant temperatures and the velocities were selected based on the typical Korean weather for the year round operation of the tower. The cooling capacity of the tower is explained with respect to varying air inlet velocities, wet-bulb temperatures, and air to cooling water volume flow rate ratio (L/G ratio). The capacity of the hybrid-type fill was much superior to other fills, but hybrid-type fill shows higher pressure drop.

  • PDF

A Study on the Nozzle Shapes of a Cross-Flow Type Hydro Turbine for Wave Power Generation (파력발전용 횡류형 수력터빈의 노즐형상에 관한 연구)

  • Choi, Young-Do;Kim, Chang-Coo;Kim, You-Taek;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
    • /
    • v.11 no.3
    • /
    • pp.30-35
    • /
    • 2008
  • The purpose of this study is to examine the effect of nozzle shapes on the performance and internal flow characteristics of a cross-flow type hydro turbine for wave power generation. The performance of the turbine is calculated with the variation of rotational speed for 4 types of the nozzle shape using a commercial CFD code. The results show that nozzle shape should be designed considering available head of the turbine. Best efficiencies of the turbine by 4 types of the nozzle shape do not change largely but overall performances varies mainly by the nozzle width. The output power of the cross-flow type hydro turbine changes considerably by the nozzle shape and a partial region of stage 2 in the runner blade passage produces maximum regional output power in comparison with the other runner blade passage areas.

Permeation Behavior of Semiconductor Rinsing Wastewater Containing Si Particles in Ultrafiltration System -II. Permeation Characteristics of Tubular Membrane (Si 입자를 함유한 반도체 세정폐수의 한외여과 특성 [II] -Polyolefin 관형막에 의한 투과분리-)

  • 남석태;여호택;전재홍;이석기;최호상
    • Membrane Journal
    • /
    • v.9 no.1
    • /
    • pp.36-42
    • /
    • 1999
  • Permeation behavior of the semiconductor rinsing wastewater contammg Si particles was examined by ultrafiltration using the polyolefin tubular membrane. Flux decline with time was due to the growth of Si cake deposited on the membrane surface and the pore plugging by Si particles. Cake filtration from the cross flow application is compared to the combination of pore blocking and cake filtration from the dead-end application. The cake resistance is 3.16 x $10^{12}$ -4.34 X $\times$$10^{12}$ $m^{-1}$ for the cross flow and 6.6 x $\times$$10^{12}$ -12.19 X $\times$$10^{12}$ $\times$$m^{-1}$for the dead-end flow, respectively. At the initial stage of operation, permeation flux of cross flow type was 1.7 time higher than that of the dead end flow type. Permeation flux of cross flow was about 42 e 1m2 hr and the rejection rate of Si particles was about 96 %. The average particle size of Si particle in the permeate was 20 nm.

  • PDF