Keyong Cheng^a,b,*, Chunzi Zhang^c, Wei Chen^a,b, Shiqiang Liang^a,†, Yongxian Guo^a,d, Xiulan Huai^a

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-6, 2012, DOI:10.5098/hmt.v3.3.3003

Abstract A film cooling method with chemical heat sink for gas turbine blades is proposed. In this method, an endothermic reaction of cooling stream occurs due to the heating from the mainstream, which leads to an improvement of film cooling effectiveness. The proposed method at different blowing ratios are computed and compared with the conventional one. The simulation result shows that due to the exsitence of the chemical heat sink the proposed method can enhance film cooling effectiveness not only in the streamwise direction, but also in the spanwise direction. More >

Wei LIU, Jiacong YIN, Pu CHEN, Xianyue SU

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.4, pp. 127-128, 2011, DOI:10.3970/icces.2011.017.127

Abstract In this paper, parametric modeling technique is employed to fast build the three-dimensional finite element shell model of a preliminarily designed large composite wind turbine blade, which is subsequently used in the dynamic analysis and static elastic aeroelastic stability analysis of the blade. In the dynamic analysis, natural frequencies and corresponding modal shapes are obtained for the blade in the case of being still as well as being rotating with rated revolution. For the rotating blade, the stress stiffening effect and spin-softening effect due to the centrifugal forces are taken into account. The static elastic… More >

W. Liu, X. Y. Su, Y. R. An, K. F. Huang¹

CMC-Computers, Materials & Continua, Vol.25, No.2, pp. 177-194, 2011, DOI:10.3970/cmc.2011.025.177

Abstract Local buckling is a typical failure mode of large scale composite wind turbine blades. A procedure for predicting the onset and location of local buckling of composite wind turbine blades under aerodynamic loads is proposed in this paper. This procedure is distinct from its counterparts in adopting the pressure distributions obtained from Computational Fluid Dynamics (CFD) calculations as the loads. The finite element method is employed to investigate local buckling resistance of the composite blade. To address the mismatch between the unstructured CFD grids of the blade surface and the finite shell elements used during More >

Je-Chin Han^*, Akhilesh P. Rallabandi

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-21, 2010, DOI:10.5098/hmt.v1.1.3001

Abstract Film cooling is widely used to protect modern gas turbine blades and vanes from the ever increasing inlet temperatures. Film cooling involves a very complex turbulent flow-field, the characterization of which is necessary for reliable and economical design. Several experimental studies have focused on gas turbine blade, vane and end-wall film cooling over the past few decades. Measurements of heat transfer coefficients, film cooling effectiveness values and heat flux ratios using several different experimental methods have been reported. The emphasis of this current review is on the Pressure Sensitive Paint (PSP) mass transfer analogy to More >

R. A. Tough^1,2, A. M. Tousi², J. Ghaffari²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.1, pp. 1-22, 2010, DOI:10.3970/icces.2010.014.001

Abstract In this paper, micro-turbine centrifugal impeller with three different blade angles was investigated by using Computational Fluid Dynamics (CFD) method. The other basic geometric parameters are held constant. The influence of the blade angles change on the observed values was determined from numerical solution of the flow in the impeller with help of the FLUENT software. The numerical simulation focused on the air flow from compressor impeller inlet to exit, and the performance of impeller is predicted. The numerical solution was performed for original impeller geometry and for two other cases, in which blade inlet More >

A. Frangi¹, M. Pagani¹, U. Perego¹, R. Borsari²

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.3, pp. 205-224, 2010, DOI:10.3970/cmes.2010.057.205

Abstract This paper is concerned with the finite element simulation of a thin membrane cutting by a sharp blade. Smeared crack finite element approaches appear to be unsuitable for this purpose, since very small elements would be required to conform to the sharp edge of the cutter. Furthermore, when the membrane material is very ductile, classical interface cohesive elements, where the cohesive forces are transmitted in the direction of the crack opening displacement, cannot correctly reproduce situations where the blade crosses the process zone. A simplified approach, based on the new concept of "directional" cohesive elements,… More >

TARSILA MARIA DA SILVA MORAES¹, CLAUDIA FRANCA BARROS², SEBASTIÃO JOSÉ DA SILVA NETO³, VALDIRENE MOREIRA GOMES⁴, MAURA DA CUNHA^1*

BIOCELL, Vol.33, No.3, pp. 155-165, 2009, DOI:10.32604/biocell.2009.33.155

Abstract Simira is a predominantly woody Neotropical genus comprising 41 taxa, 16 of which occur in Brazil and eight of them in the southeastern region of Brazil. Leaf blades of Simira eliezeriana Peixoto, S. glaziovii (K. Schum.) Steyerm., S. grazielae Peixoto, S. pikia (K. Schum.) Steyerm., S. rubra (Mart.) Steyerm., S. sampaioana (Standl.) Steyerm. were collected in the southeastern region of Brazil and fixed according to usual methods for light and electron microscopy. The leaf blades show typical characteristics of the Rubiaceae family as dorsiventral mesophyll and paracytic stomata. The presence of two bundle sheaths that extend to the upper epidermal layer, More >

Hyun Ki¹, Jongwook Choi², Sungcho Kim²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.4, pp. 69-70, 2009, DOI:10.3970/icces.2009.013.069

Abstract The wake behind rotor blade is investigated by numerical and experimental approaches. Flow structure measured through PIV is compared with numerical analysis using commercial program of ANSYS CFX adopting the RNG k-ε turbulence model. Blade model fabricated by Rapid-Prototype method has the cross section of NACA0012 airfoil and the pitch angle of 10°. The rectangular blade of which rotating diameter (D) and chord length are 0.12 m and 0.024 m respectively rotates at 240 rpm. Horizontal and vertical directions of the blade are selected as x and z coordinates, respectively, the origin locates at the rotating… More >

Wei Liu¹, Yiwei Wang¹, Yiran An¹, Xianyue Su^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.1, pp. 27-28, 2009, DOI:10.3970/icces.2009.010.027

Abstract Understanding the aeroelastic behavior of the blade is crucial to the design of large wind turbines, which has been attracting more and more research efforts. Essentially, the aeroelasticity problem of wind turbine blades is a fluid-solid interaction problem with obvious interface. At the present time, in the aeroelasticity analysis of wind turbine, CFD software based on the incompressible Reynolds-averaged Navier-Stokes (RANS) equations are not yet routinely used , in part because of the lack of experience with regard to the application of these software to various wind turbine rotors for a wide range of conditions… More >

Jyoti Ranjan Majhi, Ranjan Ganguli¹

CMES-Computer Modeling in Engineering & Sciences, Vol.27, No.1&2, pp. 25-36, 2008, DOI:10.3970/cmes.2008.027.025

Abstract The flapping equation for a rotating rigid helicopter blade is typically derived by considering 1) small flap angle, 2) small induced angle of attack and 3) linear aerodynamics. However, the use of nonlinear aerodynamics can make the assumptions of small angles suspect. A general equation describing helicopter blade flap dynamics for large flap angle and large induced inflow angle of attack is derived in this paper with nonlinear aerodynamics . Numerical simulations are performed by solving the nonlinear flapping ordinary differential equation for steady state conditions and the validity of the small angle approximations are More >