Properties of Fluids in Fluid Mechanics
![Properties of fluids](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUdTVNaXphQDPTVy-BZzvTx_3d7iUbQeICeaFk_oSBhqtHR7iJvgjrVYUhU50bl3qc_YHWlQY3rXGQbhXmbaIA6NeRkoUwsSGsxb5KxZd6CJP9mAN4PK-YetkBuBeGdsZVN9UWHwdr9eWP/s640/properties+of+fluids.png)
Mass density (ρ)
Mass density,
![ρ=(Mass of fluid)/(Volume of fluid)=m/V](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiq9sremMbgl9IBh2Qiw6TEvXqzM6Q_DAsBt4Xr94KBCZMfy8-3agNfn1Jp_2KpCXV_2HYTV-Ox0noonP1S-23HNngG7QNwo8bbc2yXNgGht8RmbJ3uxog2-r2Pvh7SwnzQa5dVB5dNrsvo/s400/mass+density+of+fluid+equation.png)
The SI unit of density is kg/m3
Dimensionally, ρ = ML-3
Weight density/ specific density (w)
It is defined as the weight per unit volume. Mathematically,Specific density,
![w= (Weight of fluid)/(Volume of fluid)=mg/V=ρg](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_3LLsn7z21G1zOomS6j3BX4Z4g65-_Nx7U-AQ1iK1dohJ99iWuwNawVFyrnU2ZI8QFwKGnpkNiSjP3VnCSF_G1vbsWHK15t6DLPJk5JgFTAkeloXP_XialsWatp87XWXxT6mrexNP4TWx/s400/specific+density+equation.png)
Here ρ = mass density and g = acceleration due to gravity.
The unit of specific density is N/m3
Dimension,
![w=(MLT^(-2))/L^3 =ML^(-2) T^(-2)](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmkUYOqUCzbT-rWi87iyqU5N_psMp4fGqujzzhxcL7ycbRhrQV5Ok83kALucVN16lN2088ldY7q-o-iF45Nh57A1NFH9kBS_0-6KbK0S4Bg_szAtiuBULzuXSgDtrMHq1r-N2uodb3xwEP/s400/specific+density+dimension.png)
Specific volume
Dimension: M-1L3
Specific gravity (s)
![Specific gravity= (Density of fluid)/(Density of standard fluid)](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYKRw3tiijzS2cTqTrlo5RA8lH9vCgnxjRXGJ9n6XUN8Gu24422mos-cMoopmhj-_-D6jAj4rNE-1MhHkFtSlLkr26rVdFTcV33t9ervYlZk7MBNGOPa0Yz-FmQpqNG52NmaBs_SFQKGR6/s1600/specific+gravity+equation.png)
It is a dimensionless quantity.
Viscosity (dynamic viscosity, µ)
It is defined as the property of a fluid that offers resistance to the fluid flow.From newton’s law of viscosity,
![μ=τ/(du⁄dy)](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEivHyJZO3moUgVrhwzUpe1UJfcSf0M5wbGWMVyPXPGP9qTDDlWnyXZmsmfG-xM7o8ahke1tYBvFoHzG6t2lHj9LGanyqGuyno9DeYslh9-Nn49RA_dpTVVOY-cpPTvbss5kDUE0aAwD91cn/s400/from+newtons+law.png)
Dimension, µ = ML-1 T-1
Kinematic viscosity (ν)
![ν= (Dynamic viscosity)/Density= μ/ρ Dimension,ν= (ML^(-1) T^(-1))/(ML^(-3) )= L^2 T^(-1)](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgF8T0D_OizCNeFCBnmG_Fpet41tjKhF5nbGkwOwUC4TCzcdfO20s7JUNT9aVBCowdQPpAMEdGEEQaCgIgwJ_Wi6nLhRCe-XACnG9uMMjJOph5d1zhbQG6N4a6c33SgtEIwh-pnimqYn2Ah/s400/kinematic+viscosity+equation+dimension.png)