A comprehensive, universally valid, elegant and yet simple method to design slender axisymmetric body of minimum wave drag in transonic and supersonic flows is developed. Computational aerodynamics is also used as a t...A comprehensive, universally valid, elegant and yet simple method to design slender axisymmetric body of minimum wave drag in transonic and supersonic flows is developed. Computational aerodynamics is also used as a tool for numerical experiments in gaining physical understanding of the drag mechanism due to the geometry of the aftbody, such as the correlation between wave drag and wave distribution of the aftbody geometry. The method utilizes MFD （modified feasible direction） based optimization program, along with the linear slender body aerodynamics, for its elegance and generic optimization convenience. The efforts are focused on inviscid flow. A practical method of reducing the wave drag of a given body is developed for both bodies with pointed end and with base area, using shock wave generator at a particular location on the aftbody. The results show that the MFD optimization program can be effectively utilized in an aerodynamic optimization problem.展开更多
The present study investigates the axisymmetric stagnation point radiativeflow of a Cu-Al2O3/water hybrid nanofluid over a radially stretched/shrunk disk.In this paper,a new mathematical model has been developed by ta...The present study investigates the axisymmetric stagnation point radiativeflow of a Cu-Al2O3/water hybrid nanofluid over a radially stretched/shrunk disk.In this paper,a new mathematical model has been developed by taking into consideration the concept of different nanoparticles concentration in a hybrid nanofluid,which are Brownian motion and thermophor-esis of nanoparticles.A new model for entropy generation has also been provided in the present study.The non-dimensional governing equations of the developed mathematical model are solved using newly developed and efficient overlapping grid spectral collocation method.Numerical stability and residual error test are provided here to show the accuracy of the numer-ical method in this mathematical model.The outcomes offluidflow,temperature,and two different types of concentration profiles are depicted,and described in graphical and tabular forms.For the limiting instances,comparison shows excellent agreement among current and results established in the literature.Increasing the strength of magneticfield is seen to increase the radial component offluid velocity as well as the entropy generated within the system.Two different nanofluid concentration profiles are increasing and decreasing with rising thermophor-esis and Brownian motion parameters,respectively,from a particular height above the disk because of the revised nanofluid boundary condition.Temperature profile increases here with increasing Biot number,and increasing Brinkman number causes higher entropy generation number for both stretching and shrinking disks.The enhanced thermal characteristics of the hybrid nanofluid over the single particle nanofluid has been observed.ª2024 The Authors.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.Ltd.展开更多
文摘A comprehensive, universally valid, elegant and yet simple method to design slender axisymmetric body of minimum wave drag in transonic and supersonic flows is developed. Computational aerodynamics is also used as a tool for numerical experiments in gaining physical understanding of the drag mechanism due to the geometry of the aftbody, such as the correlation between wave drag and wave distribution of the aftbody geometry. The method utilizes MFD （modified feasible direction） based optimization program, along with the linear slender body aerodynamics, for its elegance and generic optimization convenience. The efforts are focused on inviscid flow. A practical method of reducing the wave drag of a given body is developed for both bodies with pointed end and with base area, using shock wave generator at a particular location on the aftbody. The results show that the MFD optimization program can be effectively utilized in an aerodynamic optimization problem.
基金support of the North-Eastern Hill University,Shillong-793022,Meghalaya,Indiathe University of South Africa,Corner Christian de Wet and Pioneer Avenue,Florida Park,Roodepoort,1709,South Africa.
文摘The present study investigates the axisymmetric stagnation point radiativeflow of a Cu-Al2O3/water hybrid nanofluid over a radially stretched/shrunk disk.In this paper,a new mathematical model has been developed by taking into consideration the concept of different nanoparticles concentration in a hybrid nanofluid,which are Brownian motion and thermophor-esis of nanoparticles.A new model for entropy generation has also been provided in the present study.The non-dimensional governing equations of the developed mathematical model are solved using newly developed and efficient overlapping grid spectral collocation method.Numerical stability and residual error test are provided here to show the accuracy of the numer-ical method in this mathematical model.The outcomes offluidflow,temperature,and two different types of concentration profiles are depicted,and described in graphical and tabular forms.For the limiting instances,comparison shows excellent agreement among current and results established in the literature.Increasing the strength of magneticfield is seen to increase the radial component offluid velocity as well as the entropy generated within the system.Two different nanofluid concentration profiles are increasing and decreasing with rising thermophor-esis and Brownian motion parameters,respectively,from a particular height above the disk because of the revised nanofluid boundary condition.Temperature profile increases here with increasing Biot number,and increasing Brinkman number causes higher entropy generation number for both stretching and shrinking disks.The enhanced thermal characteristics of the hybrid nanofluid over the single particle nanofluid has been observed.ª2024 The Authors.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.Ltd.
