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An investigation of boat-tail helmet to reduce drag
Pathan, Khizar A.,Khan, Sher A.,Shaikh, Aadil N.,Pathan, Arsalan A.,Khan, Shahnawaz A. Techno-Press 2021 Advances in aircraft and spacecraft science Vol.8 No.3
A helmet is a kind of shielding equipment used to shield the head from fatal injuries. The helmet experiences drag while moving at a certain velocity. The total drag on the helmet increases with an increase in velocity. The drag force at high velocity has a significant effect on the rider's neck and may result in cervical spondylosis. Now a day's neck pain, neck sprain, spondylosis have become significant issues related to the human body. The reduction of drag on the helmet will be a boon for society, which will reduce the force on the neck. The decrease in drag is an essential field of study. The drag force can be reduced by various methods like coating on the surface, modifying the helmet's shape, etc. The study's purpose is to decrease drag on the helmet by improving the helmet's shape. The CFD analysis is carried out to find the best profile of the helmet and fineness ratio of the boat-tailed helmet to minimize drag. The CFD results are validated with the wind tunnel laboratory outcomes. Based on the findings, a considerable reduction in the drag is accomplished at the velocity of 32.5 m/s.
An investigation of boat-tail helmet to reduce drag
Pathan, Khizar A.,Khan, Sher A.,Shaikh, Aadil N.,Pathan, Arsalan A.,Khan, Shahnawaz A. Techno-Press 2021 Advances in aircraft and spacecraft science Vol.8 No.3
A helmet is a kind of shielding equipment used to shield the head from fatal injuries. The helmet experiences drag while moving at a certain velocity. The total drag on the helmet increases with an increase in velocity. The drag force at high velocity has a significant effect on the rider's neck and may result in cervical spondylosis. Now a day's neck pain, neck sprain, spondylosis have become significant issues related to the human body. The reduction of drag on the helmet will be a boon for society, which will reduce the force on the neck. The decrease in drag is an essential field of study. The drag force can be reduced by various methods like coating on the surface, modifying the helmet's shape, etc. The study's purpose is to decrease drag on the helmet by improving the helmet's shape. The CFD analysis is carried out to find the best profile of the helmet and fineness ratio of the boat-tailed helmet to minimize drag. The CFD results are validated with the wind tunnel laboratory outcomes. Based on the findings, a considerable reduction in the drag is accomplished at the velocity of 32.5 m/s.
A NEW CLASS OF GENERALIZED APOSTOL-TYPE FROBENIUS-EULER-HERMITE POLYNOMIALS
( M. A. Pathan ),( Waseem A. Khan ) 호남수학회 2020 호남수학학술지 Vol.42 No.3
In this paper, we introduce a new class of general-ized Apostol-type Frobenius-Euler-Hermite polynomials and derive some explicit and implicit summation formulae and symmetric iden- tities by using different analytical means and applying generating functions. These results extend some known summations and iden-tities of generalized Frobenius-Euler type polynomials and Hermite-based Apostol-Euler and Apostol-Genocchi polynomials studied by Pathan and Khan, Kurt and Simsek.
Representation Theory of the Lie Group T<sub>3</sub> and Three Index Bessel Functions
Pathan, Mahmood Ahmad,Shahwan, Mohannad Jamal Said Department of Mathematics 2013 Kyungpook mathematical journal Vol.53 No.1
The theory of generalized Bessel functions is reformulated within the framework of an operational formalism using the multiplier representation of the Lie group $T_3$ as suggested by Miller. This point of view provides more efficient tools which allow the derivation of generating functions of generalized Bessel functions. A few special cases of interest are also discussed.
Studies on Plant Parasitic Nematodes Associated with Banana in Sindh, Pakistan
Pathan, M.A.,Talpur, Muzaffar A.,Jiskani, M.M.,Wagan, K.H. Korean Society of Applied Entomology 2004 Journal of Asia-Pacific Entomology Vol.7 No.2
A survey of banana was conducted to study the occurrence and distribution of plant parasitic nematodes. The samples of soil and banana plants showing retarded growth were collected from three fields of Nasimabad (Khisano Mori), Tando Allah Yar and Mirpurkhas. The nematodes isolated from the roots and soil samples showed the presence of seven genera of plant parasitic nematodes, Hoplolaimus columbus, Belonolaimus longicaudatus, Helicotylenchus dihystera, Meloidogyne incognita, Xiphinema brevicol/e, Longidorus africanus and Trichodorus christiei. The maximum population densities (M. P. D %) and maximum frequency occurrence (M. F. 0 %) and prominence values (P. V %) were calculated for each nematode genus. The M. P. D %, M. F. 0 % and P. V % of H columbus (lance nematode), B. longicaudatus (sting nematode), M incognita (root-knot nematode) and Heli. dihystera (spiral nematode) were higher than those of other nematodes. The occurrence of these nematodes in relatively high population suggests their potential role in reducing banana production.
Enlarge duct length optimization for suddenly expanded flows
Pathan, Khizar A.,Dabeer, Prakash S.,Khan, Sher A. Techno-Press 2020 Advances in aircraft and spacecraft science Vol.7 No.3
In many applications like the aircraft or the rockets/missiles, the flow from a nozzle needs to be expanded suddenly in an enlarged duct of larger diameter. The enlarged duct is provided after the nozzle to maximize the thrust created by the flow from the nozzle. When the fluid is suddenly expanded in an enlarged duct, the base pressure is generally lower than the atmospheric pressure, which results in base drag. The objective of this research work is to optimize the length to diameter (L/D) ratio of the enlarged duct using the CFD analysis in the flow field from the supersonic nozzle. The flow from the nozzle drained in an enlarged duct, the thrust, and the base pressure are studied. The Mach numbers for the study were 1.5, 2.0 and 2.5. The nozzle pressure ratios (NPR) of the study were 2, 5 and 8. The L/D ratios of the study were 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. Based on the results, it is concluded that the L/D ratio should be increased to an optimum value to reattach the flow to an enlarged duct and to increase the thrust. The supersonic suddenly expanded flow field is wave dominant, and the results cannot be generalized. The optimized L/D ratios for various combinations of flow and geometrical parameters are given in the conclusion section.