Thin Layers of Low TI Material
| Line 1: | Line 1: | ||
=Description= | =Description= | ||
| − | Running KRC cases with layering (see [[Material Properties and Regolith Layering]] for | + | Running KRC cases with layering (see [[Material Properties and Regolith Layering]] for information on layering), scenarios can be encountered where thin layers are desired. When sufficiently thin layers are encountered, the time step requirement can be very small and KRC will fail to run. In order to bypass this, we can enforce a smaller time step using the 'N2' field. |
The below examples are relevant to the case found in the '''thin.pdf''' (page 10) within directory '/doc'. | The below examples are relevant to the case found in the '''thin.pdf''' (page 10) within directory '/doc'. | ||
| Line 9: | Line 9: | ||
For the following examples, we consider default KRC values and a case where a lower-TI "dust-like" layer (50 J m^-2 K^-1 s^-1/2) overlies a higher-TI layer (250 J m^-2 K^-1 s^-1/2). | For the following examples, we consider default KRC values and a case where a lower-TI "dust-like" layer (50 J m^-2 K^-1 s^-1/2) overlies a higher-TI layer (250 J m^-2 K^-1 s^-1/2). | ||
| − | When the low-TI layer is thinner than ~100 microns, KRC | + | When the low-TI layer is thinner than ~100 microns, KRC may fail to run. |
| + | |||
| + | Example: | ||
krc(lat=0.,INERTIA=50.,INERTIA2=250.,thick=64.E-6,LKofT="T",ALBEDO=0.2) | krc(lat=0.,INERTIA=50.,INERTIA2=250.,thick=64.E-6,LKofT="T",ALBEDO=0.2) | ||
> | > | ||
'''KRC failed to run for some reason''' | '''KRC failed to run for some reason''' | ||
| − | For the reference material properties (default), the necessary time step in this case (64 micron upper layer thickness) | + | For the reference material properties (default), the necessary time step in this case (64 micron upper layer thickness) is N2=98304. |
| + | |||
| + | Re-running the case with the N2 field updated executes as expected: | ||
| + | |||
| + | krc(lat=0.,INERTIA=50.,INERTIA2=250.,thick=64.E-6,LKofT="T",ALBEDO=0.2,N2=98304) | ||
| + | |||
| + | The thinnest upper layer for these material properties is 32 microns. The associated time step requirement, N2=393216. | ||
krc(lat=0.,INERTIA=50.,INERTIA2=250.,thick=32.E-6,LKofT="T",ALBEDO=0.2,N2=393216) | krc(lat=0.,INERTIA=50.,INERTIA2=250.,thick=32.E-6,LKofT="T",ALBEDO=0.2,N2=393216) | ||
Latest revision as of 18:31, 11 January 2021
[edit] Description
Running KRC cases with layering (see Material Properties and Regolith Layering for information on layering), scenarios can be encountered where thin layers are desired. When sufficiently thin layers are encountered, the time step requirement can be very small and KRC will fail to run. In order to bypass this, we can enforce a smaller time step using the 'N2' field.
The below examples are relevant to the case found in the thin.pdf (page 10) within directory '/doc'.
[edit] Examples
For the following examples, we consider default KRC values and a case where a lower-TI "dust-like" layer (50 J m^-2 K^-1 s^-1/2) overlies a higher-TI layer (250 J m^-2 K^-1 s^-1/2).
When the low-TI layer is thinner than ~100 microns, KRC may fail to run.
Example:
krc(lat=0.,INERTIA=50.,INERTIA2=250.,thick=64.E-6,LKofT="T",ALBEDO=0.2) > KRC failed to run for some reason
For the reference material properties (default), the necessary time step in this case (64 micron upper layer thickness) is N2=98304.
Re-running the case with the N2 field updated executes as expected:
krc(lat=0.,INERTIA=50.,INERTIA2=250.,thick=64.E-6,LKofT="T",ALBEDO=0.2,N2=98304)
The thinnest upper layer for these material properties is 32 microns. The associated time step requirement, N2=393216.
krc(lat=0.,INERTIA=50.,INERTIA2=250.,thick=32.E-6,LKofT="T",ALBEDO=0.2,N2=393216)
