For readers wanting to know how computational fluid dynamics (CFD) modeling might help the Stirling engine realize its full potential as a source of sustainable energy, the “closure” from Mahkamov in the December 2007 issue (1), may have proved somewhat disappointing.

The author has chosen for the most part not to answer the specific questions raised by the three discussion contributors (Burton, Burton, and Kinnersly) regarding the large differences between test data and CFD computation (2), the detailed evaluation of Figs. 13 and 14 with regard to entrapment (3), and indeed the confusion arising from some of the figure captions of the original paper (4). Instead Mahkamov has preferred to concentrate on supposed “shortcomings” in the original $γ$ engine, which I designed and which he apparently converted to $α$ mode.

Before discussing in...

1.
Mahkamov
,
K.
, 2007, “
Closure: Discussion: Design Improvements to a Biomass Stirling Engine Using Mathematical Analysis and 3D CFD Modeling
,”
ASME J. Energy Resour. Technol.
0195-0738,
129
, pp.
364
365
.
2.
Kinnersly
,
R.
, 2007, “
Discussion: Design Improvements to a Biomass Stirling Engine Using Mathematical Analysis and 3D CFD Modeling
,”
ASME J. Energy Resour. Technol.
0195-0738,
129
, p.
279
.
3.
Burton
,
J. D.
, 2007, “
Discussion: Design Improvements to a Biomass Stirling Engine Using Mathematical Analysis and 3D CFD Modeling
,”
ASME J. Energy Resour. Technol.
0195-0738,
129
, p.
280
.
4.
Burton
,
R.
, 2007, “
Discussion: Design Improvements to a Biomass Stirling Engine Using Mathematical Analysis and 3D CFD Modeling
,”
ASME J. Energy Resour. Technol.
0195-0738,
129
, p.
278
.
5.
West
,
C. D.
, 1986,
Principles and Applications of Stirling Engines
,
Van Nostrand Reinhold
,
New York
, pp.
60
63
.
6.
Mahkamov
,
K.
, 2006, “
Design Improvements to a Biomass Stirling Engine Using Mathematical Analysis and 3D CFD Modeling
,”
ASME J. Energy Resour. Technol.
0195-0738,
128
, pp.
203
215
.
7.
Sustainable Engine Systems Ltd
., 2004, “
Statement to Shareholders, August 2004
.”