qua trinh hinh thanh hon hpp va chay cua dong co diesel dupe phan anh mpt each day du va chan thuc Tuy nhien, vi^c so hoa mo hinh de lam ca so ban dau chp mo hinh mo phdng van con nhieu
Trang 1Nghien cuu so hoa mo hinh 3D duang nap, thai
va buong chay, jam co so nghien CLTU mo phong dong co diesel
• ThS LE VIET H O N G - Trudng Dgi hoe Supham Ky thudt TR Ho ChiMmh
• ThS PHAM VAN GIANG; PGS TS K H 6 N G VU QUANG - TrUdng Dqi hgc Bach khoa Hd Noi
• PGS TS TRAN TH! THU HUONG - TrUdng Dai hoc Thdnh Tdy
• PGS.TS NGUYEN ANH THI -TrUdng Dgi hoc Qudc giaTPHd Chi Minh
TOW TAT: Nhung nam gan day, nghien cuu phat
tnen dpng co diesel da va dang dupe cac nha khoa
hpc trong nuoc va ngoai nuoc quan tam Bang cac
cong cu mo phong tien tien nhu AVL-Fire, Kiva,
Ansys ICE qua trinh hinh thanh hon hpp va chay
cua dong co diesel dupe phan anh mpt each day
du va chan thuc Tuy nhien, vi^c so hoa mo hinh de
lam ca so ban dau chp mo hinh mo phdng van con
nhieu han che nen da lam ^nh hudng den qua trinh
nghien cuu danh gia va cai tien ket cau dpng co
Bai bao nay, nhom tac g i l se dua ra quy trinh so
hoa mo hinh duang nap, t h l i va buong chay cCia
hai [o?i dgng co SLT dgng buong chay ngSn each va
thong nhat, dam bao dp chinh xac so vai dpng co
thuc voi sai so bang 01mm Ket q u i nghien cuu
se la CO so quan trpng trong viec nghien cuu mo
dong CO
TL/ KHOA Dpng co dot trong, buong chay, cong
nghe thiet ke ngupc,
ABSTRACT: In recent years, research and
development of diesel engines has been and is
concerned by scientists at home and abroad With
state-of-the-art simulation tools like AVL-Fire,
Kiva, Ansys ICE, etc., the mixture and combustion
process of the diesel engine is reflected fully and
accurately However, the numencal modeling as the
basis for the simulation model is still limited, so it
has greatly affected the process of evaluating and
improving the engine structure
This paper presents the process of digitalisation
of the intake, exhaust manifold and combustion
chamber of direct internal and indirect internal
engines, ensuring a deviation from the actual
engine of 0.1mm Research results will be an
important basis in the study of the simulation of
the operating cycle, the comparison of technical
features and easy to propose the engine structural
improvement options,
KEYWORDS: Internal combustion engine
Combustion chamber Reverse engineering
I.DATVANDi
Viec sd hda mot chi tiet, bg phan hay cum chi tiet
m i y khong con la van de kho khan bdi ngay nay da co Work, ProEngineer, Catia, NX Vdi nhCfng san pham co sin, viec xay dang mo hinh sd hoa can eo eae thong sd hinh hgc cu the, dieu nay trd nen rat kho khan neu cac chinh xac cac thong sd hinh hgc cua sin pham
Cong nghe quet 3D cung cap mo hinh cua san pham
quet dudi dang dam may diem (Point Cloud) da dem lai
loi ich to Idn, khae phuc dagc nhUng kho khan trong viec
do dac cac thong so hinh hgc cua sin pham DUa tren
mo hinh dam may diem, mo hinh so hoa cua san pham
do chinh xac cao
Md hinh so hoa dudng nap thai, buong chay dgng
CO dugc nhap vao phan mem mo phdng chuyen dyng ICE Fluent Qua trinh nap khong khi, hda tron hon hop nhien lieu va khong khi, dien bien I p suat cung nhaqua trinh chly xay ra ben trong dong co dagc the hien rd
net d tdng thdi diem goc quay true khuyu Dieu nay co y
nghla rat Idn trong nghien cUu che tao dgng co, cai tien
ket cau dgng eo hadng tdi tang hieu suat cua dgng ca,
g i l m p h i t t h i i ra moi tradng Lien quan den van de nay nudc [4,5] nghien cUu tdi Uu hinh hgc dUdng nap, budng
chly dgng ca bang phan mem CFD Ket q u i nghien cufu,
cac t i c g i l da phan tich va dua ra ket eau dudng nap cung nha ket cau buong chay mdi giup elt thien he sd nap, nang cao hieu suat lam viec cua dgng eo dot trong
Tuy nhien, cae cong trinh nghien edu chu yeu tap trung vao viec thiet ke mdi ma chua danh gia dugc vdi
mo hinh so hoa cua dong cO De g i l i quyet van de nay, nhom nghien cUu da nghien cUu sd hoa mo hinh 3D dudng nap, thai va buong chly cua dgng co diesel bang cong nghe thiet ke ngagc, sCf dyng may quet 3D va phan mem RapidForm X0R3 Ket qua dat dUoe rat k h i quan
va CO the lam co sd cho cac nghien cUu mo phong chu trinh hoat dong dgng co, gop phan eho sa p h i t tnen eua nganh san xuat dgng co trong nadc
2 PHUONG PHAP NGHI6N CljfU 2.1 Ctf sd thiet ke j
Mo hinh dudng nap thai va buong chly dgng co i
137
Trang 2thu duoc dudi dang d i m may diem (Point Cloud) bang
cong nghe quet 3D Cong nghe quet 3D mat dat (TLS 3D
- Terrestrial Laser Scaning) la cong nghe tien tien dang
duoc i^ng dung trong nhieu ITnh vUc nhU:Thiet ke co khi,
kien true, y te, hgi hga, cong trinh xay dung Cong nghe
vdi toe do thu nhan rl't cao va the hien hinh anh chan
thae, chinh xac bang phuong phap do toe do phan xa
3D thu nhan dugc la tap hgp cac diem trong khong gian
ba chieu tao thanh d i m may diem
2.2 PhUcmg phap thiet ke
- M o hinh d i m may diem trong khong gian 3 chieu
thu dagc bang cdng nghe quet 3D vdi thiet bi la m i y
quet3DAT0S
- M o hinh dam may diem dugc xCrly, dung mo hinh
so hda va so sanh vdi mo hinh quet bang phan mem
RapidForm X0R3
2.3 Doi tiiting nghien cuTu
Dong eo diesel sin xuat trong nudc va dgng co
nhap khau tUThai Lan co cung dai cong suat Day la 2
dgng CO SLf dung buong chly ngan each (IDI) vasCf dung
buong ehay thong nhat (Dl)
2.4 Li^a chon thiet bj
eg rat nhieu loai may quet 3D tren thj trudng
hien nay cua cac hang noi tieng nhU: GOME, TH0R3D,
iSence, Shining 3D May quet laser ATOS la thiet bi cua
hang GOME, CHLB DUc May dugc trang bi he thong hai
camera lap the (mo phong dang mat ngadi) hoat dgng
tren nguyen tac dmh vi 3 chieu va cong nghe do triple
scan.Day la thiet bj phu hop duoc lua chon sCfdung bdi
sUcan thiet ve do chinh xac cao ma khong can lay thong
tin mau sac cua san pham quet
2.5 Xay dUng mo hinh so hoa dUdng nap thiii va
buong chay dpng cd b^ng cong nghe thiet ke ngUpc
Hinh 2.1: Quy trinh xay dung md hinh sdhda dudng nap thii v,
buong chiy dpng co
Hinh 2.2: Mau nap may duoe dat tren ban
Mo hinh so hoa dudng nap thai va buong ehay
dongcodugcthachien theo quy trinh nha Hinh 2, J Sai
so cho phep giQa mo hinh so hoa vdi dU lieu quet 3D
(dam may diem) do ngudi dung ta dinh nghla Qua trinh
so sanh, sai so daoc the hien b3ng bang mau giup ngadl
dung de dang quan sat thay vung eo sai so Idn hOn mien sai so cho phep
2.6 Quy t r i n h thae hien
2.6.1 Chuan bi thiet bi
May quet dUOc dat cd djnh tren gi^ dd Nap miy
dugc dat tren ban xoay Khoing cich XU camera den nSp
m i y khoing 50cm (Hinh 2.2) Mau quet dagc dat sao eho
anh sang xanh quet dagc het cac be mat
2.6.2 Ong dung phdn mem RapidForm X0R3 xd 1;^ dd lieu quet vd dung md hinh so hda
Hinh 2.3a: Md hinh dam miy diem ddng eo Dl
Hinh 2.3b: Md hinh dim miy diem ddng eolDI
Mo hinh so hoa dudng nap t h i i , buong chay dong
CO la mo hinh xay dung nguyen dang khoi khong khi quet 3D {dam may diem) dugc nhap vao phan mem RapidForm X0R3 va dUOc eat bo nhQng phan khong can thiet bang cong cuMesh Buildup Hinfj2.3 the hien
mo hinh dam may diem cua hai loai dgng eo cd nhd tren thi trUdng
- Sda loi be mat quet: Be mat mo hinh quet 3D xly
ra rat nhieu loi do be mat co elc di vat dan den xuat hien elc 16 hong hoac cac vet lot, lom cue bp Bang cac cong
cy trong che do Mesh nhU: Healing V\^i2ard, Decimate, Fill holes, Remove Marker , be mat cua mo hinh dUOc khSc phuc toi da, thuan lgi eho q u i trinh xay dyng mo hinh khoi 3D de dang hon
- Lam mugt be mdt ludi: iam magt be mat tong the
bang cong cu Enhance Shape giup qua trinh dung cac Sketch don g i l n hon
Hinh 2.4: Dd lieu quet da dupe phan vung
- Phdn vung doi tugng: Phan vung doi tUOng bSng
cong cy Region Group la viec phan tach mo hinh quet ra thanh elc vung co cac dang hinh hgc eO b i n nhudddng, mat phang, mat cong, mat try Viec phan vung doi tugng
CO y nghia quan trgng bdi qua trinh dUng mo hinh CAD 3D can lay cie vung doi tugng co b i n neu tren lam coscf
(Hinh 2.5)
Hinh 2.5: Dung md hinh 3D trin casdcdcSlceteh 2D
- Dung md hinh CAD 3D: Cung nhU mot so phan
mem khic, mo hinh 3D duac xay dung tr^n ca sd c^c
Trang 3Sketch 2D Cac budc xay dUng cac Sketch 2D dugc thae
Sketch da duoc tao, sCr d u n g cac cong cu Extrude, Plot,
Chamfer, Fillet de tao m o hinh so hoa t r o n g khdng gian
3 chieu n h u H/nh 2.5
- So sdnh md hinh vdi ddlieu ddm mdy diem:
M o t t r o n g nhUng tinh nang Uu viet cua phan m e m
Rapid Form X0R3 la k h i nang so sanh d U lieu may diem
va m o hinh 3D dugc xay d u n g
a) b)
Hinh 2.6: Ket qui so sanh: a) - Ddng eo co buong ehay NC;
b) • Ddng ea cd budng chiy thdng nhat
Hinh 2.7: Bing mau the hien muc sai so cua md hinh
M6 hinh so hoa dagc so sanh vdi m o hinh dam
may diem (Hinh 2.6) Can c d bang mau (Hinh 2.7) cho
thay mo hinh sd hda d a d n g nap t h i i cua d g n g co d i m
b i o sai so 0.1 m m
Do buong chay phy cua dong co sCf d y n g b u o n g
chay ngan c i e h co ket cau khuat nen anh s i n g xanh
khdng t h e chieu vao ben trong D e khac phuc dieu nay,
dugc m o t nCfa t r o n g de dang hon, phan con lai dugc xay
dung tren co sd dam may diem t h u dugc ket h g p vdi cac
cong cy do
3 KET QUA NGHIEN Cl>U VA BAN L U A N
DUa ra dUOc quy trinh xay dUng m o hinh sd hoa,
dong thdi d u n g dugc m o hinh so hoa hai loai ddng eo
CO cong suat t u o n g d u o n g d a m b i o sal sd 0.1 m m so vdi
s i n pham that
Mo hinh so hda dugc xay d u n g (Hinh 3.1) la s i n
pham can thiet cho viec m o p h o n g qua trinh hoat d g n g
cua dgng co d i m b i o d o t i n cay cao
Co the Ung dung quy trinh neu tren de xay dung mo hinh so hoa dUdng nap, t h l i va buong chay cua cac loai dgng eo khac
Tuy nhien, doi vdi mot so loai dudng nap co do cong 16n tao ra goc khuat, I n h sang xanh khong the may diem day du, gay kho khan trong viec xay dUng mo hinh so hoa Mat khac, do ehinh xac ciia md hinh so hoa phy thuoc hoan toan vao dp chinh xle eua thiet bj quet Doi vdi elc bg phan can do chinh xac cao hon, de khac phyc sai so, can p h l i lua chgn cac thiet bj quet ed do tin bjdo
4 K^T L U A N
M6 hinh so hoa dUdng nap t h l i va buong chay
dong CO thuc dugc xay dUng b^ng cong nghe thiet ke
ngugc la mot phuong phap hUu hieu, cd nhieu au diem trong viec nghien cUu md phdng chu trinh hoat dpng dgng co dot trong
Lfng dung quy trinh xay dUng mo hinh so hoa tren
CO the xay dung duoc cac mo hinh sd hoa ket cau cac loai dong CO dot trong khac; rut ngIn thdi gian, g i l m ehi phi thiet ke cat tien dgng co
Doi vdi cac loai dong co eo ket cau nhieu goc khuat,
viee quet 3D se kho c6 the thuc hien duac V\ vay, can
thien mo hinh may diem Q Tai lieu tham kh^o
[1] S.K Sabale (2013), Design and Analysis of Intake
Port of Diesel Engine for Target Value of Swirl India
[2] H.Mohamed Ntyaz (2013), Design Optimization
of Intake Port in Diesel Engine By Using CFD Analysis,
International Journal of Engineering Research & Technology, India
[3] A.M Indrodia (2014), Investigation of diference
combustion chamber geometry of diesel engine using CFD modelling ofincylinder flow for improving the performance
of engine, India
[4] Nguyen DUc Khanh [20] 4], Nghien cdu qud trinh
hinh thdnh hon hgp cua dgng ca chdy do nen bang phdn
mem Ansys/Cf, Tap chi Khoa hgc va Cong nghe
[5] V6 Thanh Vang (2015), Ndng cao hieu sudt nap
dong CO diesel mot xy-lanh trin ca sd cai tiin biin dgng hgng nap, Tap chi P h i t t n e n Khoa hoc Cong nghe
Ngay n h a n b a i : 2 0 / 1 0 / 2 0 1 8
N g i i y c h a p n h a n d d n g : 0 2 / 1 1 / 2 0 1 8
N g U c I p h i i n b i e n : PGS TS.Tran V a n LUOng
a) b)
Hinh 3.1: Ket qui xay dung mo hinh sdhda dudng nap thii,
budng chiy hai mau dpng eo
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