This article summarizes an experiment that investigated the effect of tube diameter and surface roughness on fluid flow friction factors. Three tubes were tested: a 1.14 mm diameter stainless steel tube, a 17 mm diameter smooth PVC tube, and a 15.5 mm diameter rough PVC tube coated internally with sand. The stainless steel tube results agreed with theoretical predictions. The 17 mm tube results deviated from theory likely due to the lack of a calming section. The rough 15.5 mm tube results showed friction factors were not significantly affected by Reynolds number in turbulent regimes and reasonably agreed with theoretical predictions, indicating diameter decrease has an insignificant effect on friction factor.

1. rssN..2mt4ttx
Yolune 1. Nomor 2. Edisi fafi - Iresenbr 20ll
JURNAL KEILMUAN DAN TERAPAN TEKNIK MESIN
i.la
I
l_
. Lorlrclcrc fclh

2. 7
J'_
V"t e No, 2 Juli 2Ol4
ISSXT ?OAUS&X
Dllltilttiltlllt tttlll
gtbrtifran&hJurusanTeknikbtclni*usTeknikUnhrerslbshlahramd€nganfrekt}Hd
*J't='ii'iiiiiii*il; -'6tp
Thlqy* m.g5* i,rnreram
ruama Reoaffil ll,lfr"r;;iliorn !*urut
r*n* unirrersitas lvlataram
J. Maiapahlt Xo' 62 til#ram Nusa ftttgglts Barat Kode Pc: 83125;
rdp. (0370) dlEff; fu6-it6; *t ip ru (SIoFgaJ
^^ ,
Email : Oi,nr*rXr*iiffiii*"*n* foriratana'gUn.lhrnram.ac'id
Dinenixerol0l,,( tlssfi? a&ld' xmd itmitsh.8€b4ai foum kunrrritasi. .{[am
rr$a Eori dar aphlkai
rd$ik lilecn varu mJtptd'ry1u. T1{Y,*#-il;'
P""'ksi dtr Enersi' Artikel vau
dhstimbnst€n ry grafg#rior il-r''ilvt u firutu pt**t dlts'bffin dau 6ftr
s"ffi'3ffif'ffiffi;
a.n: I K# trffins d;;;il-f"-tu o**'""'' ffi ;$tlt* ffit' du ta agn* {eeki'
ruNNAL THLUUAI{ DAN TENAPAN TEI(NIK HE3IN
DEWAN PENYUNTI}IG
: Sugimaa $T', MT', Ph'D'
: l lkde lrliratama' ST'' M'Sc" Ph'D'
: I Made Mara, ST" M'Sc'
: 1. Yesung Allo Padang' ST" MT'
2. Ir. EmmY DYah S'' MT'
3. t MadB Nrurss' ST''MT'
4. IDK' Okariawan' ST''MT'
. 5. I Made Wirauan' ST''MT'
6. IOAK Chatur Adhi W'A'' ST''MT'
: l. Aluncd lrYanto' ST'
2. Afiita Wulansari' A''Md'

3. ISSN: 2088-088X
Volume 4. Nomor 2. Edisi Juli-Desember 2014
JURNAL KEILMUAIT DAI[ TERAPAN TEKNIK MESIN
IilHflWmffiililflrmt$ffi
DAFTAR ISI
Effect of Tube Diameter and Surface Roughness on
Fluid Flow Friction Factor
Mirmanto, I GI[K Yudhyadi, Emmy Dyah S. 62 -70
Control Of The Two Dof Inverted Pendulum
7t -77Muhammad Fajar
Karakteristik Sifat Tarik Dan Mode Patahan Komposit Polyester Berpenguat Serat Tapis Kelapa
I Made Astika,I Gusti Komang Dwijana 78 -82
Analisa Unjuk Kerja N{otor Bakar Berbahan Bakar Biogas
Termurnikan Berbasis Absorber Fezot
Rudy Sutanto, Ida Bagus Alit, Nurchayati 83 - 87
Aplikasi Break Even PointPada Sistem Operasional Kapal Motor
Penyeberangan Roditha PT. Asdp Indonesia Ferry
(Persero) Cabang Lembar
Made Wijana, A.A.AIit Triadi, Firza Febriandi 88 - 95
Pengaruh Kadar Air Awal Kayu Jati Dan Suhu Curing Perekat
Pada Kekuatan Geser Sambungan Kayu Jati (Tectona Grandis)
Secara Perekatan
Sugiman, Abdul Hayyi Nu'man, Emmy Dyah Sulistyowati 96 - 102
Pengaruh Variasi Jumlah Blade Terhadap Aerodinamik Performan
Pada Rancangan Kincir Angin 300 Watt
I Made Adi Sayoga,I Kade Wiratama, Made Mara, Agus Dwi Catur 103 - 109
Pengaruh Jumlah Blade Dan Variasi Panjang Chord Terhadap
Performansi Turbin Angin Sumbu Horizontal (Tash)
I Kade Wiratama,I Made MararL. Edsona Furqan Prina. 110 - 116
Analisa Nilai Kalor Dan Laju Pembakaran Pada Briket Campuran
B ij i Nyamplung (Caloplryllm Inopltyllum) Dan Abu Sekam Padi
M. Afif Almu, Syahrul,Yesung Allo Padang lL1 -122

4. lr*e -**.llesrr. Volume 4 No. 2 Juli 201 4
s* lE&x
Mirmanto, Yudhyadi, Emmy: Effed Of Tube Dianeter
EFFECT OF TUBE DIAMETER AND SURFACE ROUGHNESS ON FLUID
FLOW FRICTION FACTOR
Mirmanto*, I GNK Yudhyadi, Emmy Dyah S.
Mechanical Engineering Department, Mataram University, Jl. Majapahit No. 62,
Mataram, NTB, 83125, lndonesia
*E-mail: mmlrmanto@gmall.com
Abstract
Experiments have been performed to investigate the effect of channel roughness and
:ameter on fluid friction. Three different diameters and roughness of tubes were used to
eramine the friction factor. The first tube made of stainless steel with an inner diameter of 1.14
-rn was investigated at Brunel University, whilst the others made of PVC with diameters of 17
-.r and 15.5 mm rough were tested at Mataram University. The stainless steelwas equipped
^fi a 200 mm calmihg section and smooth one. The 15.5 mm diameter tube was coated
-:emally with sand that had an average grain size of 0.5 mm so that the tube had a relative
:.Jghness of 0.032. The last tube with a diameter of 17 mm was smooth as explained in the
-e38 Fluid Friction Experimental Apparatus manual.
The results indicate that the llow in the stainless steel tube still obeys the theory and in
:e '7 mm tube shows a deviation in friction factor with the theory. However, this was due to no
= -:ng section installed in the test rig. Flow in the rough tube (15.5 mm diameter)
:eronitrates that the Reynolds number does not affect the friction factor in turbulent regimes
=-,: the experimental friction faclors were reasonably in a good agreement with the theory or
uoody diagram. Hence, the effect of decreasing in diameter of channels on friction fuctor is
-sgnificant.
(eyr,vords: ft iction faclor, 1
surface roughness, fl u id friction theory.
1. Background
Friction factors are important
parameters in a process that utilizes fluid
flow. This can cause high pressure drops
s,hich further cause high demands of
cumping energy. Processes that use small
:ubes/channels need carefully pressure drop
calculations because in smaller tubes, the
pressure drop becomes signi{icantly higher
than in bigger tubes. Even, in microchannels
the pressure drop is one of the major
problems that must be solved or eliminated
correctty and still being a concemed problem
in this field study. Researches on this field
are still challenging the microchannel
communities.
Still there are many contradictory
conclusions on the definition of
microchannels. Previous studies used flow
oehaviour as criteria to define microchannels,
e.g. Brauner and Moalem-Maron [1], Kew
and Comwell [2], and Peng and Wang [3].
Cn the other hand, some studies used a
dimension of channel3-to differ microchannel
tom macrochannel. Mehendale et al. [4]
dassified heat exchangers in general, in
terms of D6:
(a) Micro heat exchanger: D1, = 1 - 100
Fm.
(b) Meso heat exchanger: D1 = 100 pm - 1
mm.
(c) CompacUmacro heat exchange( Dh =
1 -6 mm.
(d) Conventional heat exchanger: Da > 6m.
Finally, based on engineering practice and
application areas, such as refrigeration
industry in small tonnage units, compact
evaporators, cryogenic industries, cooling
elements of microelectronics and micro
electro mechanical systems (MEMS)'
Kandlikar [5] subdivided channels into three
groups in terms of D6, as follows:
(a) Conventional channels: Dr, > 3 mm.
(b) Minichannels: D6 = 200 Pm - 3 mm.
(c) Microchannels: D6 = 10 - 200 Prn.
Research results published in the open
literatures are seem different each other.
Some previous studies stated that ftic'tion
factors in large diameter tubes difiered fom
those in small/micro tubes. Some indicated
higher friction factors, e.g. Urbanek et al' [6],
Pipautsky et al. [], Ptund et al. [8], Shen et
al. [9]. Other studies showed no distinclion
between experimental friction factors and
theory, e.g. Silverio and Moreira [11]' Akbari

5. Dinamika Teknik Mesin, Votume 4 No. Z Juti 2014
ISSN:2088488X Mirmanto, Yudhyadt Emny if* Cf Tube Diameter
.-
-
-
et al. [12], Mirmanto et at. [13]. However,
several studies presented friction factors that
are lower than the theory, e.g. Jiang et al.
[141
The reasons of being higher than the
theoy are u-sually due to enirance effect,
roughness effecl, dimension errors and flow
measurements. eu et al. [15] demonstrated
retativety high friction factors from
conventional theory when they measured
pressure drops for water flowing in
trapezoidal silicon microchannels with
hydrautic diameters ranging from ii pm to
169 pm. Their friction taitois *er" iUo-ui'ayo
to .l_879 hisher than theory. Xo*erei-inevjustified the deviation as bling iii"-r".uii or
the high retative roughness (i.S% rc-s.7,,/;).
Jiang et al. [16], who used L mfrocnann"l
IIh "
hydraulic diameter of 30O frr, "nOX,aqo]ilar et at. [17J, who emptoyeJ airr"Lr"
or 1.06 mm and 0.62 mm tubes elucidated
that because of the roughness their
-friction
|:^1:t wele.hjg!-er tnai tneory. Ho*"rur,
Kandtikar et al. [17] specified thaftne effect of
:rl1f roughness (retative roughness of
gj36yo) was significant onty to, tn-u
"rJfu"tdiameter test section (0.62 mm). Stren ei al.
tgl studied flow and treat
'trinsiei'tor
deionized water in rough-walled cooDer
microchannels assembled- in a ZO-.n"['n"r
.?I1v -I1"1:ctansutar
channets *"r" eOO J,yye and 800 pm deep. They apptied rhiee
different inlet temperatures; 3'0"i,' SO;C'
"na70oC and their iteynotos num-ueiJ ,"ilaftom 162 to 1257. They found tiiin"
"JiL"tgl.lurface roughness (ielative ,orghn"r-" i _
6%) on taminar flow was significait inO-tn"t
higher inlet temperatures- O"crers"O jnu
pressure drop. However, they did not exptiin
the effect of fluid temperature on the triitlon
fuctor.
ln this study, experimental friction
raoors obtained from flow in different
diameters of the tube are compared each
:I"-r :19 also.compared with ineot.-i;;arms are to see if there are any differerices of
investigated friction factors id;J i;;;"1
lube at the same Reynotdi
-
ilil;.Furthermore, as the test seciions ,r"O in ini.research were not equipped with ;lm-i;sectaons, pressure drop'predictions
-in
iiiE
inlet and.ouflet plenums are analped and
presented in the forms of graph.
2. Experimental Facility and Test Sections
.. Experiments using the 1.14 mm
diameter tube were perfoimed using the test
rig at Brunet Universrty, United Kinglom, see
Fig. 1 in Mirmanto ei at. [13]. Tn-e test ng
used in this work consisted of a reservoir
made of SS316, micropump (modet
Micropump GA-723, PF'SB),' iorioris
!o-1v119ter (model Micromotion
- -
Erit"
CMF0.10), preheaters and tesi- sections.
Deionized water was used as the working
fiuid that was set at 30"C. ttre water
temperature was measured using K type
the.rmomuple with an uncertainty 6f tO.i X
calibrated against the platinum precis-ion
Thermometer with an accuracy of t0.025 K.
To obtain pressure drops,
'two pr"r.rru
transducers modet Honeyweil 26piCO *itn
an uncertainty of t0.2 kpa were installed in
the inlet and ouflet and were ."[oirt"o
against the deadweight tester for n,gn
pressures and the water manometer for low
?le:sl1es The experiments using 15.S mm
and 17 mm tubes were conducted at
Mataram g.nry9rgity, lndonesia. ffre test rrg
used was H40B Fluid Friction Apparatus-isee
fig. t) and the test section *"re irort".i"lilv
TecQuipment Ltd, [10J.
The lengths of the test sections were
200 mm for the 1S.5 mm tuOe- Oiimeie,
(tapping 30 and 31) and g12 mm roiin" izmm tube diameter (tapping 7 and g). The'ro.5 mm tube was roughen using sand orain
with.an average size of o.s mi, girinili"
relative roughness of 0.032, see fi[. i."fn"pressure drop was measured usin--q closed
manometer with a resolution of t mm:
Three test sections employed were (i)
a stainless steel tube with an'inner OiamltJr
of
. 1.14 mm (measured using , iSinmicroscope with an accuracy ofit prm, see
Fig. 3),.200 mm tong, equipped *itn ZOfi m,tong calming sections placed before and after
Ine test section, (ii) a pVC tube with an inner
dpmeter of 17 mm and a length of 912 mm
without a calming section, (iiD-a pVC iouof,
tube with an effective diamet,er of f S.S-m'#
and.a length of 200 mm without ,
"rlringsection.
63

6. )re.1ika Teknik Masin, Volume 4 No.2 Juli 2014
SSfl;2O88{88X
Mimanto, Yudhyadi, Emmy: Effed Of Tube Ciandq
--+
15
rm
]st
'ig
rir
€l
lis
te
s.
rg
€
K
n
h
n
t
1
V
t
I
)
I
Ccr$qadPdil!
lntemal
diamettl
=17 mm
tur
$dcnE$$ion *mcrfi6'lnnEc
Itfti0ulE&r
3rrdrqtrrf,2rrDitr
Figure 1. Experimental schematic diagram ['10]
Grains sf Send
lltriln 8.rd
lmfinEird
Figure 2. Rough PiPe test section
lil) rrnSatd
PIF*datiltlOfioi,
fi*ntilrnffiqt,
lxrrrdtdm,Are(hi*
l***frmriirusl#
ft'.*ffirrftSf*tlt
FlErcrlm*i1nriboGl'F
Sdtttlity
5rCfirr0trrff*l'sfth4.
Mrflfl,eBnmfut

7. Dinamika Teknik Mesin, Volume 4 No' 2 Juli 2014
,SSrr;2088-O88X
Miniqltc '-t1a Zar', Z@Of TubeDiameter
0.562
-0.a27
0.000
Figure 3. Stainless steel test section measured using a TSER microscope
I
!-{
-.1
-{
I
--{-raI
--tI
{
I<
J
t
I
-el--d I
g!-1
ril :I
-:5r1#-
*tt
=aB4
7@f
s =/
-za
.t*
t
I
I
I
li'
3. Data Reduction
ln this studY, the inlet and outlet
pressures were measured directly, therefore,
the pressure drop is obtained by subtracting
the outlet pressure from the inlet pressure
and called as total Pressure droP,
Lp, = p,- p. (1)
where p, is the measured inlet pressure and
po is the measured outlet pressure. The
channel pressure drop is then determined
using Eq. (3), however, for the test section
that ls equipped with a calming section, the
channel pressure drop is the same as the
total pressure droP, Eq. (2).
Lp* = Lp, (2)
LPo = LP, - LP, - LP" (3)
the inlet and outlet pressLlre drops are due to the
differences between iniet and outlet tube
diameters and channel diameter- Meanwhile, in
the outlet" there is a pressure recovery due to the
deceleration of the fluid. The inlet and outlet
pressure drops can be estimated as follows:
Lp, = Lp, + Lp" = p!t,v: l2 @
+ pv.:fr-Q,, r ,l')rz a,,
Lp. = Lp, - Lp, =
4,(r,,-v")'
tz ,r,L
- pv,:l - (,n"0 t .n,)' )r 2
where dp; is the static pressure drop, dp, is
the pressure drop due to ffuid acceleration
and Ap6 is the pressure recovery due to fluid
deceleration. A"; is the channel cross
sectional area, Aiis the inlet plenum cross
sectional area and Ao is the outlet plenum
cross sectional area. V"6 is the average
channel fluid velocity and %is the average
outlet plenum fluid velocity. & is the loss
coefficient that is equal to 'l for Eq. (5) and
dependent on the ratio of channel diameter
and inlet plenum diameter for Eq. (4)' see
Table 1, whilst p is the fluid density'
The experimental friclion factor, f, is
calculated using Eq. (6), whicft is given by
f =2Lp",D_* (6)
r - pLV:
where L is the channel length and D"n is the
channel diameler. The friction factor theory in
this study is the Darcy-Weisbach equation for
laminarwhich is given bY
.-e=
:,:FJe
-'tfr
=iE-tz
.r.E
Sr*
2|trt
3-€
f,
T=t.L
u
, -R.
65
(7)

8. lra-ra Teknik Mesin, Volume 4 No. 2 Juli 20i4
ssr 2068-088X
Mirmanto, Yudhyacli, Emmy: EtforI Of Tub Eiamder
z-c lar turbulent liow in the smooth pipe, the
-.=on factor equation used is' Alasius
3t-ation which is expressed as
,f = o.316Re{.25 (g)
*-rilst for turbulent flow in a rough channel,
::e friction factor formula sitecteO ii3olebrook-White equation or Moody diagram
,rhich is written as [18]:
where k is the channel absolute roughness
and Re is the Reynolds number.
The goodness of data is analyzed
using_enor analysis proposed by Coleman
and Steele [19]. ln this study the errors
consist of bias/systematic and random erors.
Systematic erors can be minimized with a
calibration whilst random erors cannot.
Following Coleman and Steete [19J, the
random uncertainty of a measured-variable,
X, is estimated as the standard deviation, S,,
of a sample of N measurements of the
variable, X, calculated as follows:
i--l -,^i
-J: =.1-- I(-Xt - X'
Y N-1,=l
lil
X=-ZX,
Ni=l I
where Xis the mean value of the sample
population. By contrast, the systematic
uncertainty of a measured variabie, X is
calculated as the root sum (RSS) given by
Eq. (12).
a, ' ,,, , ( a, ' .,,
^--luvtl-lUvdx, ) At
l)X, ) A1
rt _
(14)
(L.
fi=r.to_osoer,f
Dis.z
I *,
(.*E)
!.qqat!9n
(14) gives the absotute uncertainty,
Ur, in the result.
Table 1. k1 , loss coefficient for the sudden
contraclion
Drl",i D, k,
0
a2
0rl
0.6
08
r0
0.*ct
043
fi aA
0.:t8
014
0
(12)
Where (8,) is the Jh of the etementat
systematic uncertainties (8,)r, (Br)z
(81)r. . ... (Br)u, estimated from, for example
calibration data and instrument specifications
given by the manufacturers. The combined
erot uc is then given by Eq. (13) and the
propagated errer can be estimated using Eq.
(14).
Source [10]
4. Results and Discussions
The inlet and ouflet pressures have
been measured and the total pressure drop
obtained from the three test section is
presented in Fig. 4. The test section #1 is the
smooth test section with a diameter of 1.14
mm equipped with calming sections installed
before and after the test section, therefore,
the total pressure drop is the same as the
channel pressure drop and the associated
flow is fully developed i?ow. The test section
#2 is the smooth test section with a diameter
of 17 mm and without a calming section and
the test #3 is the rough test section with an
average diameter of ,t5.5 mm (the actual
diameter is 17 mm and the effective diameter
is 15.5 mm) and without a calming section.
From Fig. 4, it is clear that decreasing in
diameter increases the pressure drop
significantly. For example, the decrease in
diameter ftom 17 mm to 1S.5 mm, the
pressure drop deviates of about 400% of the
pressure drop obtained in the 17 mm tube
diameter at the same Reynolds number of
20000, whilst ftom 17 mm to 1.14 mm the
qlessure drop deviates of approximately
1665670/o of the pressure drop-lained in the
17 mm tube diameter at the same Reynolds
number of 3000. This is becoming a serious
problem in the use of small to micro
channels.
ln Fig. 4, the pressure drops were
measured in the test section with diameters
of 15.5 mm and 17 mm and without a calming
(10)
(1 1)
Eb.x
Bj +sjuc= (13)
66

9. ISSN: 20884t88X ' '
rv'
' ru't zu71 Mimanto, yudhyadi,
Emmy: Efied Of TubeDiametar
m
OA
9.r.". zris the mass flow rate. For the i7
ffi:FIl1rj'j# Y.ql
-ro
;il';'i, E;:
,t?l;';::r. 1'-1r:, it"ji"i-,; i';: I #,'*
Hl"*1m:1"j31"_^_isr"i.ir,,i'iiiJ!,liiiJ?mm tube diameter. rii_
-._., .,,voE ril .ne 1t
llte sr rrfaaa ,^, r_L- ^ , s was obviously due tothe. surface rougrrness-
'rqc e.,vreusty oue to
?nft chanaar .r;^_^^- or rough channel walland channetoiimetli.
e '0',}
!ln
co tr.
.f = 12.55Re{.e2
-f*ard".dld.r
-!r&
-L{I&trrO ll=U4r
r 0=l7r
r D=EJrril
Ifr.i@I3)
yction, unless for the 1.14 mm tube
!11fg. Therefore, to obtain t"""r,"ri"Tr
lf_T"".dr:n Eo. (3) to rsl-rr,orii"'ol
.9rqpy"d The cross'sectiodi,"h;;;Lr;
Lhr"ir:i.:hi!i:"1rn'j"ixl1fl ]jorameter is O.OOO22z ,., tt"i"mi": ;ffivetocities in the channet can-be-i,illrii#E}S:
bc
! ,.,
I
b
(15)
::fl,ol:TY: droP
.becaus. t l-'i,eianJ
[T,t1?i"3,::!i?I' Eq (4) ,;; (o;"; i; l0o rt.o rele 100000
,?l,rij,fl::1i311q""t-i, ffi il-",:ffi
".::
tr
Frgure 5. Experimental friction factorsl3;j:*:jjq1"i"i, *!,;, ii,. il: EI",H
;;l",*, "j:*,j-ii ;;: [: j,
:""Jffi
"TI:l*,.t1,,: *f : 1 .
y r
-'r,;il='"il;:iJ;"'T,:
-r, ;li5
',,
F
.,=il-qr
"i,f,/
Figure 4. Total on
ooia ineo irorn' ;;^IrT:fi ,.i:K l:l,fr?",
. As there are m
rn experiments 6rPnlf-onttdictory
results
gggli i;i
"in,J'"l.ijS,;,ilr:?,#i:?
r.rctton factors are o
flt$fiHffilt'3,ffifrHtr
ffi #*,*iffiifql}',"H,:!'ffi r?tr
1si, o +sti ,ii' ffi #T ,ffrTffiffi:fll":
,HT[?",},,T;";::lJ:"'"'J?;ffi ffi 'ft,l;
rts ln the Fio_ 5, the experimental frictionre factors are in Iq. Ia"" il-" ii,"i"fl"B'"f,n!::T:,,Hrr
#m tube diameter ol
i tn =;;i; Tff $i
Meodv,:lXr#i,T
o subtracted from I
il deviati;il;il;1",i,5'3;::ffi
i',,:f lljchannel pressur
roe,z". rJriil"'f, fflf *t1, :i#"lg,"lil
g*:::r:x"fl:ff:-".: *eir witr' dr'"ill p,t
r s. s *iii l,ii' ii' lffioLlJl";H,:[:,H,'*?experiments coutd- not b. p#;;;,i.j" ,otheir lengths. if thr
*'"n in ilmin; ti:T$?"Hi"iffi,.1"f"?could be read. Adr
obtiained in tt" rinlolally'
the friction factor
h,gili ;a;' t;,i
"lL'r,*T, ?f"", i,ffi:?^,trs not due ro ttre
!1ae aiai"iur',[,]i
,tnu
roughness. Meanwrril- -;;:,=.=:-
":: ..
?rypo".d ov
^a#r'#1",?0,
Slr rr?JHfH:clata, because the corelation was created fordeveloping florv cr
,:;lrii]t#r:;H"ks,ij#n?ii
ffi:lil$*Tr'x3l^ 1'- "'tt"n- ilffi on,
19
",,*iJ ;^"ji',",]'JT,f#,ff 1fl1,"[*agree with the theon
:::, .""rv.[";Iy; "' ";fj "?1[:,,..U:cxamples of excel anatvsic ;;; :--I] ']::T"i
are described f^ll.s't
and eror analysis
experimentar data .i?l?- ,
consider ir,"
ru6e oiamef,r,;;o":1:lled in the 17 mm
regression), 6" .;o;,6"IT-l -analysis
(ANQvA
".,i.,
p","a ffi
-iy;
i'ffi: f"i:'. r.il:il,f
"?:
rs no deviation betw
results ;il;"1f1- the exPerimental
nooitionarri,-
"r- sTry- ?"? Tab{e 2.
s"[",T: ill ffi;,;: Ti+,,*j,;$:(16)
67

10. I
l
n0
}* Tdotik Mesin, Volume 4 No. 2 Juli 2014
g*N4'EEX
Mirmanto, Yudhyadi, Emnry EMOf Tube Aanxf,er
ar*r. The first point with big enor bars
rffing the furthers point, still coverc the
bius [21] correlation, henc,e, the data are
n a good agreement with the theory. The
error bars for the experimental ftiction factor
sfu,Yn in Fig. 6 are given by:
The uncertainty of the pressure drop,
diameter, tube length and fluid velocity are
known from the experiments, hence, the
relative error of friction factors can be found
and shown in Fig. 6.
-Eir
r l)=l?r
lrt
tt
lHS
Figure 6. Enor analysis for data obtained for
the 17 mm tube diameter
0
I
Iur0
Ita
rfffl.ffi'.)" (16,
t0
Table 2. Excelanalysis using ANOVA regression
s{JMnL^tRT &IIPLTT
E.trdss{rx ,*6err.5
Mr{tiple R it64487317
Rsqrraa 0-930235785
.{djDsrdB.
Sqrrac $914869307
SnodardError fi.ffi0?9)979
Ob*rr*io6s 15
.{NOy.{
q
Regrcssion I
Rcridrnl 11
Ss lA ? swnLtue.F
1-49809E-95 14988-05 1?1.v195 6.8X)13E{9
I 12351E46 8i42E48
Tsr2l 14 l-61044E45
-
ldcr€ar fin{,2fig9)78 0-0m361599 7.4&$n 4fiif46 0.l)01918091 030348el65 0-$01918091 018348&165
0-1i27819 8 0-fi11ffi)31 13.165919 632E.ig 0-127772102 0.1T}851575 0.ATJ72592 9.777851575
5. Conclusion
Experiments to see the difference of
friction factors obtained for flow in several
different diameter tubes have been
performed. For the 1.14 tube diameter, the
experiments were conducted at the Brunel
Univareity, whilst for other test sections were
performed at the Mataram University. The
results show that, for both experiments
conducted in different locations, the
experimental friction factors are not
influenced by the size ofthe tubes but by the
condition of the entrance and surface
roughness, and they obey the theory very
well. However, as the size of the tubes
reduces, the pressure drop increases
drastieally.
Acknowledgement
The first author would like to
acknowledge the lndonesia Higher Educatiqn
for the funding, and the Brund Unlversity antl
Mataram University fur the facilities.

11. r uunyaoL Emmy: Effed Of Tube Diameter
Nomenclature
R
Re
&
uc
U,
v
X
X
A
B,
D
df
f
k
kt
L
M
m
N
Cross sectional area [m2]
Systematic uncertain;
Diameter
Degree of freedom
Friction factor
) fl P..r^"_l
r.,rent sysrematic uncerrai nty
Aosorute rouglmess [m]
Losses coefficient
Tube length [m]
Maximum number of element systematic
uncertainty
l4ass flow rate [kgls]
Number of measurements
,leasured pressure [pa]
Keglesslon
Re,rnolds nurnber
Standard deviation
Combined error
Propagated error ofr function
Channel average velocity [m/s]
Measured variable
Average of measured variable
Subscript
ch Channel
i Intet
o Outlet
, Total
Greek symbol
lp Pressure drop [pa]
p Fluid density tkg;rl
I
I
I
Refercnces
t1] Brauner, N.
.&..Moalem-Maron, D.,1992, ,,tdentification
"i ii,"'l_ri" ""r
smail diameter co.nduits *O"ii,rgtwo-phase flow panem tr"n.liloi.j,Internationat Commu nicaiiin; ;;riMass Transfer vor. rg, zg _-i- ' 'qc
I2l Kew, p.A. a_ comw+ r]] rgsz"Conetations for the pr.oiltion-ii
boiting heat transfer i, .irrrr j""#"tJ,
channets", Apptiei iiii,i."i,,
13, F!i!:w f,
'iiJ:;],,a??-t
i;"Forced convection-' ,ni', #;";characteristics in ,roo"r,"].,-#rlproc. of llt HTc, 1, l6d,i;1=,1390.
t41 llrtahendate, S.S., Jacobi, A.M. &Shah, R.K., 2000, ,,Ftuid
no* ii,r,"ritran-sfer at micro and messo s;;i;;thapprication to heat
"r"n"ng"i
dliii;:,
lpy1lra Mechanics C"riJr",'.,V[1.
53(7),175 _ 193.
l5l Ka.ndtikar S.C., ioOz, ,,Two_phase
flowpattems, pressure Orop,
"nJ-f,"-ritransfer during boiting i,i'ri",.n"illi
Py_ .passases of
"il;;;ievaporators", Heat i;;".;;
16r
ffWrnY#,:t:;i:;;"]M:_A, investisation
"f
6;r;lr;;oependence of poiseuile
"il;;;. l;
microchannel
. llow,,, J. Micromech.
Microeng., Vo,. 3, 20b _'208."", ",,,",
papautsky, 1.,
_Brazzte,.l.l n-meef , f ., A
lrlzier, A., B, rsss'
-;La;'i;
h;iabehavior in micro .hrnrur ,rinJ'ri.ropolar fluid !"ory", s"rir.i.'.r-roActuator, Vot. 73, lOl _ tOA.""'"
s,
Ltl rapautsky, 1., Brazzte, J., Ameel, T. &
lryiel A., 8., rsge, ;;i;i;Jr,flrio
behaviour in
.
micro
'"ilil''r.ilg
micro polar fluid theory;, Srr"r^ ,raActuator, Vot. 73, 101'_ii;.""v'e
4,,
I8l llylo, D., Recror, o a sri-exaniz, A.,2000, ',pressure drop ,;";;;;;ffi,in a microchannet,,, Hri;-M;;;;:;,;,
Xlf't,'{ilY:fu o7'
n o ii n i',
- " "
i) oi
t91 .9h"1, _S , Xr, J.1., Zhou, J.J. & Chen.y., 2006, ',Ftow and h"; i;r;#;l;microchannets with ;ilil'1;iigyrface,', Energy Conreiin ;;;Management, v oi. qt, i g11' I| izs",,'l10l Anonymous, 20
oe o iiiiiir ;;1a','{:K{;tr::, f,LJakarta.
U1l Stverio, V. & Moreira, A.L.N., 2008.,,pressure
drop and t,""t *]irt,#i;singte-phase nrtty_Oevetoi;, ;;;;flow in microchannel.
"fji;Jl;ilSsection", f European nJirtScr-ence Co n fe rence, the Neded;;;.
.",
69

12. lanika Teknik Mesin, Volume 4 No.2 Juli 2014
ESt-21 88{88X
Mirmanto, Yudhyadi, Emmy: Etred Of Tub lliamdq
t121 Akbari, M., Sinton, D. & Bahrami, M.,
2009, "Pressure drop in rectangular
microchannels as compared with
theory based on arbitrary cross
section", J. Fluid Engineering, Yol.
131, 1 - 8.
t13] Mirmanto, Kenning, D.B.R., Lewis,
J.S. & Karayiannis, T.G., 2012,
"Pressure drop and heat transfer
characteristics for single-phase
developing flow of water in rectangular
m'rcrochannels, Joumal of Physics:
Conference Sen'es doi:10.'108811742-
6596/395/1/01 2085
t141 Jiang, J., Hao, Y. & Shi, M., 2008,
"Fluid flow and heat transfer
characteristics in rectangular
microchannel", Heat Transfer-Asian
Research, Vol.37, 197 -2O7.
t15l Qu, W., Mala, G.M. & Li, D., 2000,
"Pressure-driven water flows in
trapezoidal silicon microchannels", /nf.
J. Heat Mass Transfe4 Vol, 43, 353 -
304.
t16l Jiang, P.X., Fan, M.H., Si, c.S. & Ren,
2.P., 2001, "Thermal-hydraulic
performance of small scale micro-
channel and porou+media heat-
exchangers", lnt. J. Heat and Mass
Transfer, Vol. 44, 1039 - 1051.
1171 Kandlikar, S.G., Joshi, S. & Tian, S.,
2003, "Effecl of surface roughness on
heat transfer and fluid flow
characleristics at low Reynolds
numbers in small diameter tubes",
Heat Transfer Engineeing, Yol. 24
(3), 4 - 16.
118l Olson, R.M., 1993, "Dasar4asar
mekanika fluida teknik', Edisi 2,
Gramedia Pustaka Utama, Jakarta.
t19] Coleman, H.W. & Steele, W.G.,2009,
"Expeimentation, Validatian, and
Unceftainty Analysis for Engineers'',
3d edition, John Wiley and Son, lnc.,
Hoboken, New Jersey, USA.
t20l Mirmanto, 2013, "Single-phas flow and
flow boiling of water in rectangular
microchannels", IhesLs, Brunel
University, Uxbridge, West London,
UK.
1211 Hager W.H., 2003, "Blasius: A life in
research and education", Experiments
in Fluids, Vol. S, 566-571 doi
1 0. I 007/s00348-002-0582-9.