Characterization of the Ejector Pump Performance for the Assisted Bidirectional Glenn Procedure

This study introduces an algebraic model informed by computational fluid dynamics (CFD) simulations to investigate the performance of the assisted bidirectional Glenn (ABG) operation on a broad range of conditions. The performance of this operation, as measured by the superior vena cava (SVC) pressure, depends on the nozzle area in its ejector pump and the patient’s pulmonary vascular resistance (PVR). Using the developed algebraic model to explore this two-dimensional parameter space shows that the ejector pump can create a pressure difference between the pulmonary artery and the SVC as high as 5 mmHg. The lowest SVC pressure is produced at a nozzle area that decreases linearly with the PVR such that, at PVR =4.2 (Wood units-m2), there is no added benefit in utilizing the ejector pump effect (optimal nozzle area is zero, corresponding to the bidirectional Glenn circulation). At PVR =2 (Wood units-m2), the SVC pressure can be lowered to less than 4 mmHg by using an optimal nozzle area of ≈2.5 mm2. Regardless of the PVR, adding a 2 mm2 nozzle to the baseline bidirectional Glenn boosts the oxygen saturation and delivery by at least 15%. The SVC pressure for that 2 mm2 nozzle remains below 14 mmHg for all PVRs less than 7 Wood units-m2. The mechanical efficiency of the optimal designs consistently remains below 30%, indicating the potential for improvement in the future. A good agreement is observed between the algebraic model and high-fidelity CFD simulations.

KINERJA POMPA JET EJECTOR DENGAN MODIFIKASI HELMHOLTZ RESONATOR PADA PIPA NORMAL SHOCK

Setiap fluida yang mengalir selalu memiliki bunyi dengan intensitas dan frekwensi tertentu di dalam atau diluar ambang batas audio. Sifat akustik dari aliran fluida ini menjadi ide untuk memodifikasi normal shock diffuser dari suatu sistem fluida dengan menerapkan helmholtz resonator sebagai pengganti normal shock diffuser dengan menggabungkan dua pompa yang di aliri fluida, yaitu pompa sentrifugal tekanan rendah berkapasitas tinggi dan pompa injeksi tekanan tinggi berkapasitas rendah. Penelitian ini bertujuan untuk menentukan berapa besar pengaruh variasi jumlah pipa kapiler helmholtz resonator terhadap kinerja aliran fluida hidrolik booster-jet ejector pump. Penelitian ini bersifat eksperimental, dengan menerapkan sensor magneto flow meter arduino mega untuk mengukur kapasitas aliran fluida. Hasil penelitian ini menunjukan daya terbesar berada pada helmholtz resonator dengan jumlah 4 pipa kapiler yaitu sebesar 170,914353 Watt. Disimpulkan bahwa kinerja pompa jet-ejector mengalami peningkatan sebesar 36% dari daya sebesar 125 Watt sebelum modifikasi. Kata Kunci : Booster Jet Ejector, Resonator Helmholtz, Normal Shock Every fluid that flows always has a sound with a certain intensity and frequency, within or outside the audio threshold. The acoustic properties of this fluid flow became the idea to modify the normal shock diffuser of a fluid system by applying a Helmholtz resonator as a substitute for the normal shock diffuser by combining two pumps that are fed with fluid entering through a high-capacity low-pressure centrifugal pump and the other pump namely high pressure -low capacity injection pump. This study aims to determine how much the variation in the number of Helmholtz resonator capillaries towards performance of the hydraulic fluid flow of the booster-jet ejector pump. This research is experimental, by applying the arduino mega magneto flow meter sensor to measure the fluid flow capacity. The results of this study show that the greatest power is in the helmholtz resonator with a total of 4 capillary pipes, which is 170.914353 Watt. It is concluded that the performance of the jet-ejector pump has increased by 36% from the power of 125 Watt before modification. Keywords: Booster Jet Ejector, Helmholtz Resonator, Normal Shock

Studi Kinerja Fresh Water Generator Di Kapal AHTS PETEKA 5401

Fresh water is one of the primary needs on board. Shortage of fresh water on board, has a considerable risk, and to overcome the problem of lack of fresh water, commercial vessels are generally equipped with fresh water generators where the aircraft works with the process of evaporating seawater in the evaporator and seawater vapor is cooled with the way condensation in the distillation plane to produce fresh water. The fresh water genertaor parts are Evaporator, Condenser, Demister, Water ejector, Ejector Pump, and Destillate Pump. Then the Cause of Declining Freshwater Production in Fresh Water Generators is a decrease in fresh water production in fresh water generators. As for how to overcome so that the production of fresh water produced by fresh water generators does not decrease ie when the evaporator plate is cleaned, make sure the gasket on the plate must be in good condition, then cleaned from the crust attached to the plate, once every six months the nozzle and diffuser ( throwers) are removed and examined. And check the ejector pump for leaks and from corrosion such as impellers, casings, rings and shafts. In generating data the author uses descriptive research that is used to find the broadest possible knowledge of the object of research at a particular time. Descriptive research is research whose purpose is to explain or describe an event, condition, object whether a person, or everything related to variables that can be explained using either numbers or words. Keywords : Fresh Water Generator, Evaporator, Ejector Pump Air tawar merupakan salah satu kebutuhan primer di atas kapal. Kekurangan air tawar di atas kapal, mempunyai resiko yang cukup besar, dan untuk mengatasi masalah kekurangan air tawar, kapal-kapal niaga pada umumnya dilengkapi dengan fresh water generator dimana pesawat ini bekerja dengan proses menguapkan air laut di dalam evaporator dan uap air laut didinginkan dengan cara kondensasi di dalam pesawat destilasi sehingga menghasilkan air tawar. Bagian-bagian fresh water genertaor adalah Evaporator, Kondensor, Demister, Air ejektor, Pompa ejektor, dan Pompa destillate. Kemudian Penyebab Menurunnya Produksi Air Tawar Pada Fresh Water Generator adalah menurunnya produksi air tawar pada fresh water generator. Adapun cara mengatasi agar produksi air tawar yang di hasilakan fresh water generator tidak menurun yaitu pada saat plat evaporator dibersihkan, pastikan gasket pada plat harus dalam kondisi baik, kemudian dibersihkan dari kerak-kerak yang menempel pada plat, setiap enam bulan sekali nozzle dan difuser (penyembur) dilepas dan diperiksa. Dan periksa pompa ejektor dari kebocoran dan dari korosi seperti impeller, casing, ring, dan shaft. Dalam menghasilkan data penulis menggunakan penelitian deskriptif yang digunakan untuk menemukan pengetahuan yang seluas-luasnya terhadap objek penelitian pada suatu masa tertentu. Penelitian deskriptif adalah penelitian yang tujuannya untuk menjelaskan atau mendeskripsikan suatu peristiwa, keadaan, objek apakah orang, atau segala sesuatu yang terkait dengan variabel-variebel yang bisa dijelaskan baik menggunakan angka-angka maupun kata-kata. Kata Kunci : Fresh Water Generator, Evaporator, Pompa Ejektor

MENJAGA KESTABILAN SUHU RUANG EVAPORATOR BERDAMPAK PADA HASIL PRODUKSI AIR TAWAR FRESH WATER GENERATOR

<p><em>Maintaining a Fresh Water Generator from the loss of vacuuming means getting the best fresh water production process. The balance of the heated substance and the heater measurement inside the evaporator could effect on the steam result or even could influence the steam process. There are many factors that could cause the loss or the decreasing of vacuuming when operating Fresh Water Generator, such as system leakage, the lack of sea water volume used for vacuuming, the balance of water ejector capability to maintain the steam volume inside Fresh Water Generator, the brine ejector capability to maintain the unused brine water and condension water being exhaust of Fresh Water Generator. </em></p><p><em><strong>Keywords</strong>: Condenser, Evaporator, Ejector, Ejector Pump</em></p><p>Menjaga serta mempertahankan kondisi Fresh Water Generator dari kevakuman merupakan hal yang harus selalu diperhatikan secara baik,dengan tujuan untuk mendapatkan proses produksi air tawar secara optimal. Pengaturan keseimbangan antara media untuk memanaskan dan media untuk dipanaskan didalam ruang evaporator berdampak pada hasil uap yang diproduksi ataupun justru berpengaruh terhadap proses penguapan. Banyak faktor penyebab hilangnya ataupun turunnya kevakuman pada saat pengoperasian fresh water generator,seperti kebocoran pada sistem,kurangnya kapasitas volume air laut yang digunakan oleh ejector pump untuk proses kevakuman, tidak seimbangnya kemampuan air ejector menjaga jumlah uap yang ada di dalam ruang fresh water generator , kemampuan brine ejector menjaga jumlah air brine dan air kondensasi yang tidak tertampung diruang kondensor untuk di buang keluar dari ruang fresh water generator.</p><p><strong>Kata kunci</strong> : Kondensor, Evaporator, Ejector, Ejector Pump</p>