Aerodynamic Performance of an Annular Combustion Chamber Cooling with Swirler Design

Cong-Truong Dinh,Xuan-Truong Le,Trong-Nghia Hoang,Quang-Anh Pham 한국유체기계학회 2021 International journal of fluid machinery and syste Vol.14 No.1

Gas turbines play a crucial role in the aviation industry as they are primary sources of power for most aircraft. The combustion chamber is one of the three essential part of jet engines, together with compressor and turbine. Energy is generated when fuel is burned in the combustor. In the primary zone, the recirculation flow is of great importance to aerodynamic performance. Swirlers, fitted in the dome around the fuel injector, can alter the behavior of the recirculation flow and thus, impact combustion performance. The vortex behind a swirler can be easily controlled by changing the swirl angle. In addition, changing the vortex angle leads to a difference in mixing between fuel and air. This paper investigates the effects of swirler design, based on the swirl angle, on aerodynamic performance of an annular combustion chamber in cooling condition using three-dimensional Reynolds-averaged Navier-Stokes equations with the SST turbulence model.

Effects of pin-fins with trapezoidal endwall on heat transfer characteristics in gas turbine blade internal cooling channels

Cong-Truong Dinh,Khanh-Duy Cong Do,Duy-Hung Chung,Hoanh-Son Truong 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.5

All the studies about pin-fins so far focus on investigating the geometry and configurations of pin-fins to perceive the mechanism of the flow and vortices and maximize the heat transfer efficiency index (HTEI) of the channel. However, questions remained about the effect of the endwall, which can be used to develop and conserve the vortices around the pins. These vortices are typically the key factors influencing the heat transfer capacity of the channel but have not been investigated properly. This work numerically investigates the vortices development and preservation of the channel with three types of endwall-turbulation systems, i.e., the flat endwall, the protruding endwall, and the indented endwall, and the structure of the flow therein. The heat transfer characteristics, which include Nusselt number, friction factor, and HTEI, are studied and compared between all cases with Reynolds numbers ranging from 7400 to 36000. It is reported in the results that, with these new endwall configurations, the high heat transfer regions near the pin-fins are remarkably enlarged compared to the flat endwall. Moreover, in the meantime, both the new endwall configurations enhanced the heat transfer capacity of the channel near the pin-fins, represented by the Nusselt number. The HTEI of these two new designs outperform the baseline case by 37.8 % with the indented endwall and 15.9 % with the protruding endwall. It is discovered that the increase in Nu when applying the trapezoidal endwall to the channel is mainly produced by the combination of the indentations and the protrusions. The protrusions are meant to increase the momentum of the gas passing through it so that the flow will interact more productively with the heated wall. The indentations, on the other hand, enlarge the area of the horseshoe vortices (HV) and preserve it when it is on the verge of collapse. By varying the height of the indentation and the protrusion, it is found that with the small height, both configurations produce a much lower friction factor but much higher heat transfer capacity, leading to a relatively higher HTEI, up to 77.7 % and 41.5 % higher than the flat endwall case of the indented and protruding endwall, respectively. The investigations resulted in diminishing the wake behind the pin-fin with a high-height trapezoidal endwall. For the indented endwall, the deep endwall increases the velocity at the entrance of the indentations and induces more turbulence when the flow exits them. These phenomena result in higher heat transfer of the channel. Besides, the highly elevated protruding endwalls increase heat transfer by creating more turbulence around them and the pin-fins but induce more pressure loss penalty. These results indicated the great potential for improving the heat transfer capability of pin-fins by optimizing endwall con-figurations, which could benefit future designs for industries.

Effects of Rotor-Bleeding Airflow on Aerodynamic and Structural Performances of a Single-Stage Transonic Axial Compressor

Dinh Cong-Truong,Vu Dinh-Quy,김광용 한국항공우주학회 2020 International Journal of Aeronautical and Space Sc Vol.21 No.3

This paper presents the effects of airflow bleed from the rotor shroud surface between leading and trailing edges on aerodynamic and structural performances of a single-stage transonic axial compressor, NASA stage 37, using three-dimensional Reynolds-averaged Navier–Stokes equations with the k–ε turbulence model. A small airflow mass flow rate is bleed throughout a rotor-bleeding ejector which designed by seven parameters: bleeding angle (°) and ejection angles (°), ejection depth (D), bleeding thickness (H), bleeding position from rotor leading edge (L) in flow direction, bleeding ejection curvature (R), and bleeding width contacted on rotor shroud surface (W). The numerical results for aerodynamic performance: total pressure ratio, adiabatic efficiency, and stall margin of a transonic axial compressor were validated with a smooth casing experimental data. A parametric study of seven design parameters of rotor-bleeding ejector above combined with a small ejection mass flow rate in a single-stage transonic axial compressor for aerodynamic and structural performances was performed. The numerical results show that all aerodynamic performance increases with bleeding airflow from rotor shroud surface, the total deformation on rotor tip leading edge in spanwise direction reduces with a very small increasing in Von-Mises stress in a reference-bleeding airflow as compared to the results of smooth casing.

Effects of Airflow Injection and Ejection in a Casing Groove on Aerodynamic Performances of a Transonic Axial Compressor

Cong-Truong DINH,Kwang-Yong KIM 한국전산유체공학회 2014 한국전산유체공학회 학술대회논문집 Vol.2014 No.10

This paper investigated the effects of airflow injection and ejection in a casing groove on aerodynamic performances of a transonic axial compressor using three-dimensional Reynolds-average Navier-Stokes equations with the k-? turbulence model and scalable wall function. The variable airflow injections of 1.5%, 2.0%, 2.5% and 3.0% of the annulus flow are directly injected into the casing groove with a height of 3% blade tip chord length at the leading edge of blade, where the airflow is significantly decelerated by separation, to energize airflow and to reduce the tip blockage accumulation. The airflow ejections of 0.8%, 1.0% and 1.2% of the annulus flow are bleed from casing groove at the trailing edge of blade to remove low momentum airflow in the tip clearance region. The numerical results show that the aerodynamic performances are improved by the application of the casing groove combined with blade tip injection and ejection in a transonic axial compressor.

Effect of Air Bleeding on Aerodynamic Performance of a Single-Stage Axial Compressor

Cong-Truong Dinh(딩꽁쯔엉),Kwang-Yong Kim(김광용) 한국유체기계학회 2016 유체기계 연구개발 발표회 논문집 Vol.2016 No.11

정익 슈라우드 공기분사가 단단 천음속 축류압축기의 공력성능에 미치는 영향

딩꽁쯔엉(Cong-Truong Dinh),마상범(Sang-Bum Ma),김광용(Kwang Yong Kim) 대한기계학회 2017 大韓機械學會論文集B Vol.41 No.1

본 연구에서는 단단 천음속 축류압축기 정익부 슈라우드에 공기분사기를 설치하는 방안을 제시하고 이 것이 공력성능에 미치는 영향을 분석하기 위해 매개변수 연구를 수행하였다. 분사기의 곡률, 폭, 정익 앞전으로부터의 거리, 원주방향 각도 및 공기분사 비율을 변수로 선정하였고, 각 변수의 변화에 따른 공력성능 영향을 분석하기 위해 삼차원 레이놀즈평균 나비어-스톡스 방정식을 사용한 공력해석을 수행하였다. 매개변수 연구 결과, 정익 분사가 적용된 단단 축류압축기의 공력성능이 향상되었고, 공력성능이 공기분사 비율에 민감한 영향을 받는 것이 확인되었다. 원주방향 각도의 비율이 10%일 때 전압력비와 단열 효율이 가장 크게 향상되었다. In this study, stator shroud injection in a single-stage transonic axial compressor is proposed. A parametric study of the effect of stator shroud injection on aerodynamic performances was conducted using the three-dimensional Reynolds-averaged Navier-Stokes equations. The curvature, length, width, and circumferential angle of the stator shroud injector and the air injection mass flow rate were selected as the test parameters. The results of the parametric study show that the aerodynamic performances of the single-stage transonic axial compressor were improved by stator shroud injection. The aerodynamic performances were the most sensitive to the injection mass flow rate. Further, the total pressure ratio and adiabatic efficiency were the maximum when the ratio of circumferential angle was 10%.

Modeling and Energy Management Strategy in Energetic Macroscopic Representation for a Fuel Cell Hybrid Electric Vehicle

Dinh, To Xuan,Thuy, Le Khac,Tien, Nguyen Thanh,Dang, Tri Dung,Ho, Cong Minh,Truong, Hoai Vu Anh,Dao, Hoang Vu,Do, Tri Cuong,Ahn, Kyoung Kwan The Korean Society for Fluid Power and Constructio 2019 드라이브·컨트롤 Vol.16 No.2

Fuel cell hybrid electric vehicle is an attractive solution to reduce pollutants, such as noise and carbon dioxide emission. This study presents an approach for energy management and control algorithm based on energetic macroscopic representation for a fuel cell hybrid electric vehicle that is powered by proton exchange membrane fuel cell, battery and supercapacitor. First, the detailed model of the fuel cell hybrid electric vehicle, including fuel cell, battery, supercapacitor, DC-DC converters and powertrain system, are built on the energetic macroscopic representation. Next, the power management strategy was applied to manage the energy among the three power sources. Moreover, the control scheme that was based on back-stepping sliding mode control and inversed-model control techniques were deduced. Simulation tests that used a worldwide harmonized light vehicle test procedure standard driving cycle showed the effectiveness of the proposed control method.

A Study on Wave Energy Conversion Using Direct Linear Generator

Phan Cong Binh,Dinh Quang Truong,Kyoung Kwan Ahn 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

Ocean wave has made a significant contribution in renewable energy resource. Since, lots of researches relating to wave energy generation (WEG) have been carried out. Among them, an electrical power take-off system (PTO) which can be used to combine wave extracting device and an electrical generating system is especially paid attention to. In this paper, a floating-buoy wave energy converter (WEC) using a linear generator is proposed and studied. The mathematical model is then derived in order to investigate the WEC operation. In addition, the principle to improve the WEC performance based on a so-called adaptive ballast control technique is also presented. Numerical simulations using MATLAB/Simulink have been performed in the time domains to evaluate the energy generation efficiency of this device. The WEG of using the suggested WEC is finally compared with that of using a conventional WEC based linear generator.

Modeling and Energy Management Strategy in Energetic Macroscopic Representation for a Fuel Cell Hybrid Electric Vehicle

TOXUAN DINH,Le Khac Thuy,Nguyen Thanh Tien,Tri Dung Dang,Cong Minh Ho,Hoai Vu Anh Truong,Hoang Vu Dao,Tri Cuong Do,안경관 사단법인 유공압건설기계학회 2019 드라이브·컨트롤 Vol.16 No.2

Fuel cell hybrid electric vehicle is an attractive solution to reduce pollutants, such as noise and carbon dioxide emission. This study presents an approach for energy management and control algorithm based on energetic macroscopic representation for a fuel cell hybrid electric vehicle that is powered by proton exchange membrane fuel cell, battery and supercapacitor. First, the detailed model of the fuel cell hybrid electric vehicle, including fuel cell, battery, supercapacitor, DC-DC converters and powertrain system, are built on the energetic macroscopic representation. Next, the power management strategy was applied to manage the energy among the three power sources. Moreover, the control scheme that was based on back-stepping sliding mode control and inversed-model control techniques were deduced. Simulation tests that used a worldwide harmonized light vehicle test procedure standard driving cycle showed the effectiveness of the proposed control method.

Effects of non-vertical linear motions of a hemispherical-float wave energy converter

Do, Hoang-Thinh,Dinh, Quang-Truong,Nguyen, Minh-Tri,Phan, Cong-Binh,Dang, Tri-Dung,Lee, Seyoung,Park, Hyung-Gyu,Ahn, Kyoung-Kwan Elsevier 2015 Ocean engineering Vol.109 No.-

<P><B>Abstract</B></P> <P>The hydraulic power-take-off mechanism (HPTO) is one of the most popular methods in wave energy converter (WECs). However, the conventional HPTO with only one direction motion has some drawbacks which limit its power capture capability. This paper proposes an <I>adjustable slope angle wave energy converter</I> (ASAWEC) and investigates the effect of slope angle on the performance of the proposed wave energy converter to find the optimal slope angle with the purpose to increase the power capture capability as well as energy efficiency. A mathematical model of components from a floating buoy to a hydraulic motor was modeled. A small scale WEC test rig was fabricated to verify the power capture capability and efficiency of the proposed system throughout experiments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper proposed an adjustable moving angle wave energy converter (AMAWEC). </LI> <LI> Mathematical model of AMAWEC was presented and simulated. </LI> <LI> An AMAWEC test rig were fabricated to do the experiment in variety of wave conditions and moving angle in the water tank. </LI> <LI> The effect of moving angle on the performance of a wave energy converter was investigated to find the optimal moving angle in each wave condition. </LI> <LI> Finally, the effectiveness of AMAWEC has been verified by experimental results. </LI> </UL> </P>