Two-Dimensional and Axisymmetric Unsteady Flows due to Normally Expanding or Contracting Parallel Plates

Table 1

The analytic results of 𝑓(𝜂) at different terms of approximation compared with the numerical results (RK4) for the axisymmetric case.

𝑆	𝜂	3 Terms	5 Terms	7 Terms	Numerical (RK4)
–1.5	0.2	0.319474	0.319526	0.319526	0.319526
	0.4	0.603652	0.603825	0.603830	0.603830
	0.6	0.822574	0.822863	0.822875	0.822876
	0.8	0.956580	0.956789	0.956800	0.956801
–0.5	0.2	0.302545	0.302582	0.302582	0.302582
	0.4	0.578028	0.578082	0.578082	0.578082
	0.6	0.800737	0.800780	0.800780	0.800780
	0.8	0.947686	0.947702	0.947702	0.947702
0.5	0.2	0.290353	0.290322	0.290322	0.290322
	0.4	0.559299	0.559253	0.559252	0.559252
	0.6	0.784341	0.784304	0.784303	0.784303
	0.8	0.940717	0.940704	0.940703	0.940703
1.5	0.2	0.281032	0.281010	0.281010	0.281010
	0.4	0.544851	0.544780	0.544779	0.544779
	0.6	0.771493	0.771374	0.771371	0.771371
	0.8	0.935127	0.935038	0.935036	0.935036