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All Journal LONTAR Jurnal Teknik Mesin Undana (LJTMU )
Gurnawati, Gurnawati
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Mechanical Engineering

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Studi Eksperimental Efisiensi Rumah Pengering Umbi Porang Sistem Hibrid (Energi Surya–Biomassa) dengan Variasi Beban Pengeringan Gurnawati, Gurnawati; Kameo, Putry P. E.; Koehuan, Verdy A.
LONTAR Jurnal Teknik Mesin Undana (LJTMU ) Vol 9 No 02 (2022): Oktober 2022
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/ljtmu.v9i02.9389

Abstract

Pengeringan adalah salah satu proses tahapan pasca panen yang penting mengingat proses ini menyerap cukup banyak energi. Diperkirakan 12% dari total energi yang digunakan pada industri pangan dan pertanian adalah untuk pengeringan. Salah satu alternatif pengeringan adalah menggunakan Solar Dryer sebagai sarana penangkap energi. Panas yang terakumulasi tersebut dipakai untuk mengeringkan Porang yang berada dalam Solar Dryer. Hasil penelitian menunjukkan bahwa kadar air akhir umbi porang setelah pengeringan per hari untuk tiap variasi beban diperoleh nilai terendah 9,90 %bb pada variasi beban 10 kg dan laju pengeringan tertinggi 0,550 kg/jam dari asumsi kadar air awal 70 %bb. Sedangkan pada variasi beban 8,5 kg (H1) dan 14 kg (H3), kadar air akhirnya masih memenuhi standar yaitu 11,4 %bb dan 10,98 %bb dengan laju pengeringan terendah 0,330 kg/jam (H3). Jika dikaitkan antara distribusi temperature maupun kelembaban udara dalam rumah pengering dengan laju pengeringan, konsumsi energi spesifik (KES), dan efisiensi pengeringan, maka terdapat perbedaan antar variable tersebut. Hal ini menunjukkan hasil perbandingan terbalik antara konsumsi energi spesifik, namun berbanding lurus dengan laju pengeringan dan efisiensi pengeringan
Analisis Perubahan Tekanan Udara Perangkat Oscillating Water Column dengan Metode phi-Buchingham Kasi, Paulinus Sargius; Jasron, Jahirwan Ut; Gurnawati, Gurnawati
LONTAR Jurnal Teknik Mesin Undana (LJTMU ) Vol 10 No 01 (2023): April 2023
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/ljtmu.v10i01.11051

Abstract

ABSTRACT The increase in human population along with the times and technology must be increasingly difficult to separate from energy needs, one of which is the need for electrical energy. One source of energy that has not been widely utilized is ocean wave energy. Ocean wave power plants basically have a working principle, namely converting ocean wave energy (mechanical energy) into electrical energy. One of the wave energy conversion system technologies is the Oscillating water column (OWC) technology. Technology Oscillating Water Coloumn this, using the air pressure from the watertight chamber to movewells turbine This turbine will then be used to generate electricity. Forms of studies that can be carried out to study the phenomenon of changes in device air pressure Oscillating Water Coloumn is mathematical modeling. One of the mathematical modeling can be done by phi-Buchingham. Using Buckingham's Pi theorem dimensional analysis can make it easier to analyze and make experimental steps faster and more focused. Keywords: Ocean waves, Oscillating Water Coloumn (OWC), Barometric pressure, phi-Buchingham
Pengujian Skala Laboratorium Performa Rotor Turbin Angin Ganda Kontra-Rotasi Melalui Variasi Rasio Geometri PAE, KOSTAN; Koehuan, Verdy A.; Gurnawati, Gurnawati
LONTAR Jurnal Teknik Mesin Undana (LJTMU ) Vol 11 No 01 (2024): April 2024
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/ljtmu.v11i01.14082

Abstract

The aim of this research is to determine the performance of a double rotor counter-rotation wind turbine on the geometric configuration of the CRWT rotor ratio. Tests were carried out on a laboratory scale with a turbine rotor blade model using the S826 airfoil series issued by NREL (National Renewable Energy Laboratory), where the rotor diameter at field scale (full scale) was 0.944 m. The blade is made through a 3D printing process using PLA (polylactic acid) material with an S826 airfoil profile. Laboratory scale testing uses a wind tunnel with test section dimensions of 0.6 m long, 0.3 m wide and 0.3 m high and the wind speed is considered uniform, varying from 3 m/s to 5 m/s. The performance of CRWT with rotor geometry ratio D1/D2 < 1 is better than CRWT with rotor geometry ratio D1/D2 > 1 at rotor distance Z/D1= 0.4. Varying the turbine geometry ratio with a smaller front rotor diameter, the power coefficient of the front rotor turbine is higher than the turbine with a larger front rotor diameter.
Simulasi Kinerja Termodinamika Refrigerator Dengan Injeksi Cairan Menggunakan R515A Dan R515B Amalo, Alexander C.; Gurnawati, Gurnawati; Dwinanto, Matheus Magnus
LONTAR Jurnal Teknik Mesin Undana (LJTMU ) Vol 11 No 01 (2024): April 2024
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/ljtmu.v11i01.14914

Abstract

This research aims to analyze and compare the thermodynamic performance of refrigerators using two types of refrigerants, namely R515A and R515B, with liquid injection techniques. Refrigerators are important devices in a variety of applications, including the food, pharmaceutical, and household refrigeration industries. This simulation includes important variables such as pressure, temperature, mass flow, and thermophysical properties of both refrigerants. In addition, it also considers fluid injection technique variables such as injection amount, injection time, and injected fluid properties. The research results show a performance comparison between R515A and R515B in terms of thermal efficiency, cooling capacity, and power consumption. It was found that the use of R515B with certain liquid injection resulted in a significant increase in the overall efficiency of the refrigerator system. The results show that proper setting of the injection amount and injection time can optimize the performance of the refrigerator system. Selecting the right refrigerant and liquid injection strategy can produce a more efficient system. This research provides in-depth insight into the thermodynamic aspects of refrigerator systems and illustrates the importance of refrigerant selection and operational techniques in achieving maximum efficiency.
Simulasi Kinerja Thermodinamika AC Split Menggunakan Refrigeran R32, R1234yf, dan R290 Lamawuran, Marianus Adventus; Gurnawati, Gurnawati; Dwinanto, Matheus Magnus
LONTAR Jurnal Teknik Mesin Undana (LJTMU ) Vol 11 No 01 (2024): April 2024
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/ljtmu.v11i01.14937

Abstract

Split AC is the process of regulating temperature, humidity, cleanliness, and air distribution in a room so as to achieve thermal comfort conditions for the occupants in it. The purpose of this research is to simulate the thermodynamics of a Split AC using environmentally friendly refrigerants R32, R1234YF, and R290 using Genetron Propertis software version 1.4.1. The method used in this study is a standard air conditioning performance simulation using R32, R1234YF, and R290 refrigerants with Genetron Propertis software version 1.4.1. The simulation results of the basic cycle refrigeration system performance with the working fluid R32 for the condensation temperature are maintained constant, because the temperature of the refrigerant gas through the condenser must be higher than the ambient temperature, condensation occurs in the condenser, so that the refrigerant changes form to liquid. From the simulation of the split AC thermodynamic performance, an increase in the evaporation temperature will have a significant impact on increasing the consumption of pumping power, increasing the mass ratio, and COP in the system.
Co-Authors Amalo, Alexander C. Jahirwan Ut Jasron Kameo, Putry P. E. Kasi, Paulinus Sargius Lamawuran, Marianus Adventus Matheus M. Dwinanto PAE, KOSTAN Verdy A. Koehuan