more paper stuff

Author: zingale

paper/paper.md

@@ -24,15 +24,18 @@ affiliations:
   index: 1
 - name: University of Southampton
   index: 2
-  
+
 date: 10 August 2018
 
 bibliography: paper.bib
 ---
 
 # Summary
 
-pyro
+pyro is a python-based simulation framework designed for ease of
+implementation and exploration of hydrodynamics methods.  It is
+built in a object-oriented fashion, allowing for the reuse of
+the core components and fast prototyping of new methods.
 
 In the time since the first pyro paper [@pyroI], the code has
 undergone considerable development, gained a large number of solvers,
@@ -49,13 +52,14 @@ with new undergraduate researchers in our group to introduce them to
 the ideas of computational hydrodynamics.  But the current framework
 has evolved to the point where pyro is used for prototyping
 hydrodynamics solvers before implementing them into science codes.  An
-example of this is the 4th-order compressible solver built on the ideas
-of spectral deferred corrections (the `compressible_sdc` solver).  This
-implementation was used as the model for the development of higher-order
-schemes in the Castro hydrodynamics code [@castro].  The low Mach
-number atmospheric solver (`lm_atm`) is based on the Maestro code [@maestro]
-and the pyro implementation will be used to prototype new low Mach number
-algorithms before porting them to science codes.
+example of this is the 4th-order compressible solver built on the
+ideas of spectral deferred corrections (the `compressible_sdc`
+solver).  This implementation was used as the model for the
+development of higher-order schemes in the Castro hydrodynamics code
+[@castro].  The low Mach number atmospheric solver (`lm_atm`) is based
+on the Maestro code [@maestro] and the pyro implementation will be
+used to prototype new low Mach number algorithms before porting them
+to science codes.
 
 The current pyro solvers are:
 
@@ -64,21 +68,25 @@ The current pyro solvers are:
     finite-volume scheme$^\star$, and a WENO method$^\star$)
 
   * compressible hydrodynamics (including a second-order unsplit CTU
-    scheme, a method-of-lines piecewise linear solver$^\star$,
-    and two 4th-order finite-volume schemes, one with Runge-Kutta
-    integration and the other using a spectral deferred corrections method$^\star$)
+    scheme, a method-of-lines piecewise linear solver$^\star$, and two
+    4th-order finite-volume schemes, one with Runge-Kutta integration
+    and the other using a spectral deferred corrections
+    method$^\star$)
 
-  * diffusion using a second-order discretization
+  * diffusion using a second-order implicit discretization
 
-  * incompressible
+  * incompressible hydrodynamics using a second-order approximate
+    projection method.
 
-  * low Mach number atmospheric solver
+  * low Mach number atmospheric solver$^\star$, using an approximate
+    projection method.
 
-  * shallow water equations solver
+  * shallow water equations solver$^\star$
 
 (solvers since the first pyro paper are marked with a $^\star$).  Also
 new is support for Lagrangian tracer particles, which can be added to
 any solver that has a velocity field.
 
 
+
 # References