1st Edition by John R. Howell
Complete Chapter Solutions Manual
are included (Ch 1 to 12)
** Immediate Download
** Swift Response
** All Chapters included
,Table of Contents are given below
1. Why Study Radiation Energy Transfer?
2. The Basics of Thermal Radiation.
3. Radiative Properties at Interfaces.
4. Predicted and Measured Surface Properties.
5. Configuration Factors for Diffuse Surfaces.
6. Radiation Exchange in Enclosures Bounding Transparent Media.
7. Radiation Combined with Boundary Conduction and Convection.
8. Properties of Participating Media.
9. Radiative Transfer in Participating Media.
10. Numerical methods for radiative transfer problems.
11. Radiation in Solids, Windows, and Coatings.
12. Emerging Areas.
,Solutions Manual organized in reverse order, with the last chapter displayed first, to ensure
that all chapters are included in this document. (Complete Chapters included Ch12-1)
CHAPTER 12- SOLUTIONS
12.1 Consider a SiC grating similar to that reported by Greffet et al. (2002) (see Figure 12.5). Comment on
the structure of the grating and the emission wavelengths. List your suggestions for the use of such
structures.
SOLUTION: The Greffet group has shown how the angular profile of emissivity can be altered using a
diffraction grating [Greffet et al. (2002)]. They have fabricated gratings on a SiC substrate (see Figure 12.4).
The diffraction by the grating of surface waves, propagating at the surface of the SiC substrate, leads to
emissivity in narrow solid angles, as depicted in Figure 12.5. The emissivity thus obtained is about 20 times
larger compared to a flat source. Strong peak of emissivity is near a wavelength = 11.36m . This
extraordinary behavior is due to the coherence properties of surface waves that are observed only in the
near-field if the substrate is flat. These structures can be used to modify the radiative properties of different
materials with applications in energy harvesting, thermal imaging and advanced nanomanufacturing
processes.
12.2 A 2D enclosure consists of two opposing black surfaces with cold surroundings. The overall objective
of the inverse boundary condition design problem is to find the required temperature distribution on the
upper heater surface that produce the desired temperature and energy flux over the lower design surface,
T1 and q1(x1). L
x2
2 = 1, T 2(x 2) = ?
T surr = 0 T surr = 0 h
1 = 1, T 1, q1(x 1)
x1
(a) Show that the boundary conditions on the heater surface and design surface are related by a Fredholm IFK,
W
Eb2 ( x2 )k ( x1, x2 ) dx2 = Eb1 − q1 ( x1 ) where Eb2(x2) = T24(x2), or, in dimensionless form,
x2 = 0
1
2 ( X 2 )k ( X 1, X 2 )dX 2 = 1 − 1 ( X 1 ) with = Eb/T14, = q/sT24, and X = x/L.
X 2 =0
1 H2
The kernel of the integral is given by k ( X 1, X 2 ) = where H = h/L.
2 H 2 + ( X 2 − X 1 )2 3/2
(b) Discretize the integral equation so that the upper and lower surfaces are split into 30 uniform elements.
Following Equation (12.2), transform the integral equation into a matrix equation Ax = b, assuming that the
desired non-dimensional energy flux distribution over the design surface is 1 = AX12−BX1−C with A = B =
16 and C = 6, and the plates are separated by a dimensionless gap height of H = 0.4.
(c) Carry out a singular value decomposition on the A matrix and plot the singular values.
(d) Use TSVD to obtain 2 for different values of p and plot the corresponding values of 1 assuming that 1 is
known.
(e) Repeat Part (c) for different values of H and provide a physical explanation for the trends in the singular
values.
(f) Repeat Part (d) for H = 0.6, but this time using a constant energy flux of = −1. How do these results compare
to the temperature distribution predicted for a parabolic energy flux profile?
12.1
, 12. Applications of Radiation Energy Transfer
SOLUTION:
The integral equations describing the system are Equations (6.16.1) and (6.16.2). Discretizing the integral
equations results in a 30x30 matrix equation Ax = b. The singular values of A, plotted below, reveal the
matrix to be ill-conditioned because deconvolution of the Fredholm IFK is ill-posed. The plateau at 5x10-17
is due to finite numerical precision.
A set of solutions is found using TSVD with p = 25, 27, 29. Because of the problem symmetry, the
solutions obtained using p = 26 and p = 27, are identical, as are the solutions found with p = 28 and p =
29. The solution becomes more regular as the number of truncated summation terms increases. In all
cases the recovered energy flux over the design surface closely matches the desired energy flux.
The singular values of A change with H because of the smoothing action of the kernel. As H increases the
problem becomes more ill-posed because there is more geometric “blending” between the elements on the
heater surface and the design surface. Consequently, for larger values of H, many potential temperature
distributions over the heater surface produce similar irradiation distributions over the design surface.
12.2