1 files changed, 26 insertions, 0 deletions
diff --git a/858/CH4/EX4.21/example_21.sce b/858/CH4/EX4.21/example_21.sce
new file mode 100755
index 000000000..f00ef1cb9
--- /dev/null
+++ b/858/CH4/EX4.21/example_21.sce
@@ -0,0 +1,26 @@
+clc
+clear 
+printf("example 4.21 page number 160\n\n")
+
+//to find the pressure gradient
+
+Q=0.0003    //in m3/s
+d=0.05    //in m
+A=(3.14*d^2)/4;
+
+u=Q/A;
+
+density=1000;   //in kg/m3
+viscosity=0.001;  //in Pa-s
+e=0.3;
+dp=0.00125;   //particle diameter in m
+
+Re=(dp*u*density)/(viscosity*(1-e));
+fm=(150/Re)+1.75;
+L=0.5   //in m
+delta_Pf=fm*((density*L*u^2)/dp)*((1-e)/e^3);   //in Pa
+
+//applying bernoulli's equation, we get
+delta_P=delta_Pf-(density*9.8*L);
+pressure_gradient=delta_P/(L*1000);   //in kPa/m
+printf("required pressure gradient = %f kPa/m of packed height",pressure_gradient)