Mechanical Design of a "Clam Shell" Type Dome For TÜBİTAK

National Observatory

BILKENT UNIVERSITY

Project Description

Milestones and Methods Results

Abstract

Conclusions Bibliography

Turkeywithadelicatelyinnovateddesign1.First step consisted of dis9nguishedtechnical perspec9ve and conceptualdes ign . Other s teps fo l lowed thepredetermined technical perspec9ve andthe design has achieved its current form.Pursuing such dis9nguished technicalperspec9ve allowed us to succeed infinalizing theproject,andperformprac9calandexperimental tests toproveour claimssuch as isola9ng the scien9fic instrumentsplacedinsidethedomefromoutereffects.

Clamshell domes are used to protect the telescope from the environmental condi9ons.Thatisneededbecause,telescopesareimmobilizedattheobservatoriesandtheyneedtostaythereinallweathercondi9ons. 2

Domes are designed to be in sphericalshapebecause,suchgeometry is thebestagainstharshenvironmentalcondi9ons,interms of par9culate and fluid flow. Thedesign consists of four slices and twomotorsthatactoneachhalfofthesphere.Abeltmechanism isused to transmit thetorquegeneratedbythemotorintermsoftensiontoallowmobilityofslices.

TechnicalProper.es• Resistantto300km/hwind• Wateranddustresistance• Impactresistance(eg.hail)• Reliabilityofslicemo9onthrough

•  Scaled down, 3D printedversion for a visual aid andmechanical analysis of thesystem.

•  Proper mechanisms, motors,gears are selected suited fort h e c o n d i 9 o n s a n drequirementsforthedesign

•  Recogni9on of the design tobuild a full-scale product byourmentor.

The main problem of tradi9onal clamshell domes is solved which was to prevent externalfactors such as dust, snow, water etc. from infiltra9ng inside of the dome and resultantlyinterfering with the proper opera9on of the telescopes and the dome itself. To test andevaluatethefunc9onalityandcompetenceofthedome,aprototypewasmanufacturedvia3Dprinter.Severaltestswereperformedonthejointareawhereslicesmeetaroundthepivottube3. Itwas seen that theprototype succeededandwithstood theeffectsofwind,dust and lowtemperature.Severaldesignchangessuchasthicknessandorienta9onweremadetoimprovethestrengthofthedesign.AtensiletestonthePLAmaterialwasperformedwhichshowedthattheprototypecouldwithstand27.3MPaofstress.The comparison of the standardclamshell domes and our design canbe seen aside. First figure containsgapswhichisaproblemsolvedinourdesign by a more compact andintelligentlayoutoftheslices.Originaldesign4implementsgreygasketsthatare added later by TNO as a way toblock incoming par9cles meanwhilenewdesignhasasmoothersurfaceontheoutsideforabeYerflowdeflec9onandalsohasnoexternalcomponents.

The produced clamshell dome is capable of preserving a small telescope to be used forDIMMobserva9ons onthesiteofTÜBİTAKNa9onalObservatory,attopoftheSaklıkentMountain-Antalya.Alterna9vely, it canalsobeapplicable formilitary cases. It is thefirstdomes9c clam-shell dome ever designed and produced in Turkey, with much lessproduc9oncostthanitsforeignequivalents.Domes9ca9onwillalsoeliminatetheposs ib le communica9on andtransporta9onproblemswithforeigndome companies, where most ofthem are located in U.S.A. orCanada. Moreover, if the case ofdome export trade may arise infuture, it will provide revenue tona9onaleconomyandrecogni9oninma r ke t s . T he r e s ea r ch anddevelopment (R&D) in this area iscurrently inac9ve. This projectassuresknow-howaccumula9onandwill lead possible future R&DprojectswiththeassistanceofTNO.

[1] “Solar -Differen9al ImageMo9onMonitor at the TÜBİTAK Na9onalObserva tory” , TUG, [On l ine ] .www.tug.tubitak.gov.tr/dokumanlar/tug_sdimm/[2] “Dome Types”, Vik Dhillon,University of Sheffield, [Online].www.vikdhil lon.staff.shef.ac.uk/t e a ch i n g / ph y217 / t e l e s c ope s /phy217_tel_domedes.html[3] “Introduc9on to Thermal andFluids Engineering”, Deborah A.Kaminski,MichaelK.Jensen,2011[4] “Astrohaven Domes”, Fiberglassclamshell domes for observatory,planetarium, radar tracking housing,portable backstand [Online].www.astrohaven.com/

•  Milestones for this project are determined in coopera9onwith TUG, and sa9sfiedthroughouttheprocessofdesignandproduc9on.

•  Acquisi9onofourownprojectthroughpersonalaYemptsandnetworkcapabili9es•  Sa9sfyingtheneedsforini9aldocumentsandrequirementsoftheprojectandobtainingBIDEBfund•  Completeliteraturesearchfor intendedclamshelldometypeandestablishingafinal

conceptsuitedforallunitsandindividualsinvolved.•  Successfuldesignofcomponentsof thedesiredend-productandadequatesolu9ons

totheproblemsgiveninthedefini9on.

Mechanical Design of a Clamshell Dome for TÜBİTAK Na9onal Observatory (TNO and itscommonnameofTUG)getsitsmo9va9onfromdesigningaclamshelldomewithadiameterof 1.5 m with an integrated controller mechanism, and pursue unorthodox methods toincrease isola9on at intersec9on points between slices and at joint sec9on around pivottube which also coincides with the standards of TÜBİTAK Na9onal Observatory, andrepresentsthenameof

bothwormgearandbreak-motor

Figure3:Simula9onAnalysisoftheWindResistanceCriteria.Windcan’tenterthe

dome

Figure5:Simula9onAnalysisoftheWindResistanceCriteriadoneviaCOMSOL.

Figure4:ComparisonofdomesbetweentheoneinAntalya(leo)andourdesign(right)

Figure6:Mechanicalassembly

Görkem Kavak Oğulcan Temiz

Osman Yalçınkaya

Samet Barış Yılmaz Akmeşe

Yiğitcan Coşkuntürk

Academic Advisor: Prof. İlker Temizer Company Advisor: Spc. Kadir Uluç

Figure1:Domewehavedesigned

Figure2:Sliceshavemorecompactlayoutinourdesign