An analysis is presented of compressible viscous flows past wavy walls without restricting the mean flow to be linear in the disturbance layer. Linearization of the compressible disturbance equations results in a system of six first‐order differential equations for the perturbation quantities. The method of orthonormalization is used to control the error growth in the numerical solution of these equations. The present results agree more closely with experimental data than the results obtained by using Lighthill’s theory, which restricts the mean flow to be linear in the disturbance layer.

Compressible boundary layers over wavy walls

T he influence of various parameters on the flow rate and skin friction is examined in this paper, when the bounding surface is subjected to sinusoidal disturbances. It is noticed that, as the angle of inclination is increased, the flow rate decreases initially and thereafter the effect is found to be reverse. However, the phenomenon is found to be periodic as the frequency of excitation is increased. It is seen that, for a constant angle of inclination, skin friction is periodic in nature. Such a pattern is attributed due to the sinusoidal movement of the fluid bed. Further, when the frequency of excitation is held constant as the angle of inclination is increased, the skin friction increases. An interesting observation is that, in the absence of angle of inclination, and irrespective of frequency of excitation, the skin friction is found to be absent. It is seen that, increase the concentration of the fluid contributes to the decrease in the flow rate. However, the effect seems to remain same, even when the frequency of excitation is held constant and the fluid concentration is increased. Further, when the concentration of the fluid medium is held constant, and increase in the frequency of excitation   the skin friction  decreases. In general it is seen that, increase in the porosity of the bounding the flow rate  increases.  Also, when the frequency of excitation is held constant, increase in the fluid concentration increases the flow rate.

Critical Analysis of on the Flow Rate and Skin Friction of an Incompressible Fluid of Second Order Type with Respect to the Frequency of Excitation when the Boundary is Subjected to Periodical Disturbances

In this paper the effect of various flow entities which influences the flow rate has been discussed in detail. It is observed that, for a constant frequency of excitation, the flow rate increases as the angle of inclination of the fluid bed increases. However, as the frequency of excitation increases, the flow pattern is found to be sinusoidal. Further, as the visco elasticity of the fluid increases, the flow rate decreases. Also, as the porosity of the fluid bed increases, the flow rate also increases. It is noticed that, as the time increases, the flow rate is found to be decreasing. All such observations are illustrated graphically. 

Keywords: Second order fluid, Porous media, Visco elasticity, Angle of inclination, Frequency of excitation and Flow rate.

https://ijma.info/index.php/ijma/article/download/67/26

Effect of frequency of excitation on the flow rate of an incompressible fluid of second order type by creating sinusoidal disturbances on the boundary

In this paper the effect of slope of the fluid bed with respect to various other fluid parameters such as visco elasticity, porosity, frequency of excitation and time on the behaviour of skin friction has been analyzed. When the angle of inclination is held constant and when , it is noticed that, the skin friction increases and when a reverse trend is observed. Also, when the frequency of excitation increases, the skin friction increases and when , the effect is found to be in the opposite direction. An interesting phenomenon is that, when the angle of inclination is increased, the skin friction remains constant till and thereafter it decreases. Also, irrespective of the visco elasticity of the fluid, the skin friction increases linearly with respect to the angle of inclination of the plate. However, for a fixed angle of inclination, as the visco elasticity of the fluid increases, the skin friction increases. Therefore, it can be concluded that, the participating parameters in the skin friction shows the significant effect on the skin friction. The skin friction is found to be linear (either positive or negative) depending upon time. Further, as the frequency of excitation increases, the skin friction is also on rise. Also, the angle of inclination does not show any effect as the porosity is varied and later shows significant effect. Further, the skin friction is directly proportional to the angle of inclination even when the density of the fluid is varied. The effects of all the above parameters on the skin friction have been presented graphically. 

Keywords: Porous media, second order fluid, Visco elasticity, Frequency of excitation, angle of inclination and Skin friction.

Characteristic behaviour of inclination of the fluid bed on the skin friction of an incompressible fluid of second order when the fluid bed is subjected to sinusoidal disturbances

In this paper the effect of time on the flow rate when the bounding surface is subjected to sinusoidal disturbances has been studied. The fluid under the consideration is of second order. When the angle of inclination of the fluid bed is increased, the flow rate is found to be periodic in its nature over a period of time. Further, it is noticed that, for constant angle of inclination, as the visco elasticity of the fluid is increased, still the periodic nature of flow rate is preserved. An interesting phenomenon that can be attributed for the above is due to the strong intra molecular forces in the fluid medium. Further, when the time parameter is constant and as the porosity of the fluid bed is increased, for a constant time, a decreasing trend in the flow rate is noticed. However, the graphical and analytical results illustrate an interesting phenomenon. Also, for a constant visco elasticity of the fluid and for a fixed angle of inclination and porosity, as the frequency of excitation of the fluid bed is increases, the flow rate is found to be sinusoidal. And at times, the back flow is also noticed and this is due to strong intra molecular forces in the fluid medium. Further, as the frequency of excitation increases, in general the flow rate increases. All such observations are illustrated graphically.

http://www.ijma.info/index.php/ijma/article/download/245/106

Analysis of effect of time on the flow rate of an incompressible fluid of second order type when the bounding surface is subjected to sinusoidal disturbances

In this paper the nature of skin friction with respect to various flow entities has been studied in detail. It is noticed that, as the porosity of the fluid bed increases, the skin friction decreases and as porosity increases not much of effect skin friction is noticed. As the visco elasticity of the fluid increases, the skin friction increases. Further, when the time parameter and frequency of excitation are held constant and even if porosity is varied, the skin friction is found to be constant. All such observations are illustrated graphically.

On the characteristic performance of porosity with respect to skin friction of an incompressible fluid of second order type by creating sinusoidal disturbances

K. Rama Krishnaiah

Papers

Effect of frequency of excitation on the flow rate of an incompressible fluid of second order type by creating sinusoidal disturbances on the boundary

Characteristic behaviour of inclination of the fluid bed on the skin friction of an incompressible fluid of second order when the fluid bed is subjected to sinusoidal disturbances

Analysis of effect of time on the flow rate of an incompressible fluid of second order type when the bounding surface is subjected to sinusoidal disturbances

On the characteristic performance of porosity with respect to skin friction of an incompressible fluid of second order type by creating sinusoidal disturbances

Critical Analysis of on the Flow Rate and Skin Friction of an Incompressible Fluid of Second Order Type with Respect to the Frequency of Excitation when the Boundary is Subjected to Periodical Disturbances