Determination Of Skin Friction Research Articles

Determination of skin friction on a rotating sphere in magnetic levitation

Determination of skin friction on a rotating sphere in magnetic levitation

Magnetically driven chemically reactive Casson nanofluid flow over curved surface with thermal radiation

AbstractDuring this exploration, Casson nanofluid is taken over a sheet that is curved and stretching in nature and its flow equations are analyzed. Radiation and slip provisions are also taken into consideration. A magnetic field of uniform rate is provided. Convective heat and mass transference extract dominant conclusions from the system. The Brownian migration together with thermophoresis is also included in the flow structure. Moreover, the chemical reaction of higher‐order within the nanoingredients also generates interest. Guiding equations furnished by the selected model are resettled to ordinary differential equations of nonlinear type by significant similarity transformation. We have worked on MAPLE‐19 software to work out this with a suitable accuracy rate. Upshots are shown with diagrams and tables. Corresponding physical consignment such as Nusselt number has been analyzed. Determination of skin friction and moreover Sherwood's number is also in the area of interest. Magnificent advancement in heat sifting is dealt with by magnetic and Brownian motion specification. The graphs prescribed the upshots of thermophoresis and slip parameters. Outcomes convey that temperature together with concentration are reduced for stretching parameters but velocity lines are enhanced. Heat transport goes up for magnetic and Brownian motion framework but elevated outcomes are spotted for radiative flow in contrast to nonradiative flow. Mass transfer is reduced for chemical reaction components but the rate of augmentation is elevated for higher‐order chemically reactive flow. Mass Biot number and temperature Biot number both increase the concentration and temperature transport, respectively.

Determination of skin friction in strong pressure-gradient equilibrium and near-equilibrium turbulent boundary layers

The conventional Clauser-chart method for determination of local skin friction in zero or weak pressure-gradient turbulent boundary layer flows fails entirely in strong pressure-gradient situations. This failure occurs due to the large departure of the mean velocity profile from the universal logarithmic law upon which the conventional Clauser-chart method is based. It is possible to extend this method, even for strong pressure-gradient situations involving equilibrium or near-equilibrium turbulent boundary layers by making use of the so-called non-universal logarithmic laws. These non-universal log laws depend on the local strength of the pressure gradient and may be regarded as perturbations of the universal log law. The present paper shows that the modified Clauser-chart method, so developed, yields quite satisfactory results in terms of estimation of local skin friction in strongly accelerated or retarded equilibrium and near-equilibrium turbulent boundary layers that are not very close to relaminarization or separation.

Dynamic Unstructured Method for Relative Motion of Multibody Configuration at Hypersonic Speeds

Conclusions Oil Ž lm interferometryprovedeasierto use in a  ight-testenvironment than anticipated, and interference fringe images sufŽ cient to allow determinationof skin friction within§10% uncertaintywere obtainedfor each ightat nearlyall oil line locations.The locationof boundary-layertransitionwas evident from abrupt change in fringe spacing. Despite the relatively simple nature of the instrumentation and data recording used in this experiment, it was possible to obtain skin friction measurements at a large number of locations simultaneously. Using self-adhesive Mylar sheets to provide an optical surface made it possible to measure skin friction without modiŽ cation of the aircraft. This method offers the possibility of making detailed skin friction measurements in  ight testing more cheaply and easily than is possible with other methods.

The Evaluation of Local Skin Friction in Compressible Flow

In a recent note, Allen has investigated the use of Preston tubes and Clauser charts for determining the skin friction in supersonic, boundary-layer flows. He concluded that the Preston tube was best used in conjunction with the law of the wall of Fenter and Stalmach but that the Baronti and Libby wall law was most suitable for determining local skin friction from velocity profiles; both methods are complex and do not permit the direct use of Clauser charts. The present note presents a simple transformation which permits incompressible Clauser charts to be used for the evaluation of skin friction in supersonic flows; the method is applicable to both adiabatic and nonadiabatic situations. Some conclusions, based on experimental experience, are drawn regarding the determination of skin friction by sub-layer methods.